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Influence of infrared energy on early growth rates of poultry 1973

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INFLUENCE OF INFRARED ENERGY ON EARLY GROWTH RATES OF POULTRY BY NOUREDDINE B. ABDALLAH B.Sc. Texas A & M U n i v e r s i t y , 1969 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE i n the Department of A g r i c u l t u r a l E n g i n e e r i n g We accept t h i s t h e s i s as conforming to the r e q u i r e d standard THE UNIVERSITY OF BRITISH COLUMBIA December, 1973. In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f the r e q u i r e m e n t s f o r an advanced degree at the U n i v e r s i t y o f B r i t i s h Columbia, I agree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y purposes may be g r a n t e d by the Head o f my Department o r by h i s r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . Department o f A g r i c u l t u r a l E n g i n e e r i n g The U n i v e r s i t y o f B r i t i s h Columbia Vancouver 8 , Canada Date December 1 7 , 1 9 7 3 ABSTRACT The r a d i o s i t y method of r a d i a n t interchange a n a l y s i s of e n c l o s u r e s was used to p r e d i c t the i n t e n s i t y and the u n i f o r m i t y of thermal r a d i a t i o n w i t h i n a c o n t r o l l e d e n v i r o n - ment chamber. The chamber was designed f o r t e s t i n g the e f f e c t s of i n f r a r e d r a d i a t i o n on young b r o i l e r s . The w a l l s of the chamber were assumed to be grey and separated by a r a d i a t i v e l y n o n - p a r t i c i p a t i n g medium. A l s o the b l a c k globe thermometer method was used to c a l c u l a t e the i n c i d e n t r a d i a t i o n a t d i f f e r e n t l o c a t i o n s i n the chamber. Then, the r e s u l t s o b tained by the two mentioned methods, were compared. Two separate experiments were designed f o r d i f f e r e n t purposes. The f i r s t experiment was to study the i n f l u e n c e of i n f r a r e d r a d i a t i o n on p o u l t r y . In t h i s experiment, two l e v e l s of r a d i a t i o n were t e s t e d and the r e s u l t s were compared to those obtained by use of a c o n v e n t i o n a l heat lamp brooding system. The second experiment was to compare a c o n t r o l l e d temperature, warm a i r brooding system, to a c o n v e n t i o n a l heat lamp brooding system. The r e l a t i v e e f f e c t s i n both sets of experiments were measured by use of the weekly growth r a t e index. TABLE OF CONTENTS PAGE TITLE PAGE ABSTRACT i i TABLE OF CONTENTS i i i LIST OF FIGURES V LIST OF TABLES v i LIST OF SYMBOLS XX. ACKNOWLEDGEMENTS x i i i INTRODUCTION 1 LITERATURE REVIEW 3 EXPERIMENTAL DESIGN 7 EXPERIMENTAL MATERIAL AND PROCEDURE 12 DESCRIPTION OF EXPERIMENTAL EQUIPMENT 15 1. Thermal R a d i a t i o n Brooding Experiment 15 2. Warm A i r Brooding Experiment 17. DETERMINATION OF THE RADIANT HEAT LOAD DISTRIBUTION IN THE CHAMBER 19 1. R a d i o s i t y Method 19 Assumptions 19 Theory 20 S o l u t i o n and R e s u l t s 22 2. Black Globe Thermometer Method 27 Temperature of Radiant Heat Panels 27 Mean Radiant Temperature (MRT), Radiant Heat Load (RHL) and Black Globe Temperature (BGT) 28 R e s u l t s . 34 3. Comparison of Radiant Heat Load R e s u l t s Obtained. .- by the R a d i o s i t y Method and the Black Globe Thermometer Method 34 i v . PAGE DATA ANALYSIS 3 8 1. General Models 3 8 (a) A n a l y s i s of v a r i a n c e of the experimental d a t a 38 (b) Regression a n a l y s i s of the experimental data 39 2. R e s u l t s and D i s c u s s i o n of the Analyses of Va r i a n c e 40 (a) I n f r a r e d brooding experiment 40 TEST 1: New Hampshires 40 TEST 2: U.B.C. B r o i l e r s 44 TEST 3: U.B.C. B r o i l e r s . 46 TEST 4: U.B.C. B r o i l e r s 49 (b) Warm a i r brooding experiment: Commercial B r o i l e r s 50 TESTS: 5 and 6 50 3. R e s u l t s of the L i n e a r M u l t i p l e Regression Analyses 51 (a) I n f r a r e d brooding experiment 51 (b) Warm a i r brooding experiment 52 4. I n f r a r e d and Warm A i r Brooding: A Comparison 53 CONCLUSIONS 57 LIST OF REFERENCES 59 APPENDIX A 62 APPENDIX B 69 APPENDIX C 7 8 APPENDIX D 87 V . LIST OF FIGURES FIGURE PAGE 1 Schematic of the a i r c o n d i t i o n i n g system used with the i n f r a r e d r a d i a t i o n e x p e r i - ment 16 2 Development of the chamber showing s u r f a c e i d e n t i f i c a t i o n number and the 9 l o c a t i o n s of the globe 21 3 B a s i c geometry used to c a l c u l a t e the c o n f i g u r a t i o n f a c t o r s by equations 7, 8 and 18. 25 4 Mean Radiant Temperature nomograph f o r 2-in diameter b l a c k globe thermometer 32 V I , LIST OF TABLES TABLE PAGE Black globe temperature (BGT) and r a d i a n t heat load (RHL) as per treatment and brooding p e r i o d f o r t e s t s 1, 2 and 3 8 Black globe temperautre (BGT) and r a d i a n t heat l o a d (RHL) as per brooding p e r i o d for t e s t 4 9 Dry bulb temperautre (°F) as per brooding p e r i o d f o r t e s t s 5 and 6. ( R e l a t i v e humidity - 5Q%) 11 Computer output f o r the value of the r a d i o s i t y (B) i n BTU hr f t f o r the 10 s u r f a c e s of the chamber as s p e c i f i e d i n F i g u r e 2. 27 P r e d i c t e d and experimental RHL (BTU h r ^ 1 f t ~ 2 ) d i s t r i b u t i o n i n the environmental chamber 37 Average weekly body weights i n grams and average weekly growth, r a t e s as by treatment, f o r t e s t s 2, 3, 4, 5 and 6 (males) 54 S c h e f f e ' s l i m i t s a t the 95% c o n f i d e n c e l e v e l f o r the s p e c i f i e d c o n t r a s t s f o r t e s t s 2, 3, 5 and 6 (males) 55 LIST OF TABLES APPENDIX A Average s u r f a c e temperature, emmittance and s u r f a c e area of the s u r f a c e of the chamber C o n f i g u r a t i o n f a c t o r s between the s u r f a c e s of the chamber M a t r i x of c o e f f i c i e n t s and column v e c t o r of c onstants f o r the s o l u t i o n o f the system of l i n e a r non-homogeneous equations C o n f i g u r a t i o n f a c t o r between the sphere a t d i f f e r e n t l o c a t i o n s and the w a l l s of the chamber I n c i d e n t r a d i a t i o n on the globe f o r the 9 l o c a t i o n s A i r v e l o c i t y , a i r temperature, globe temperature and r e s u l t i n g mean r a d i a n t temperature of the globe f o r the 9 l o c a t i o n s LIST OF TABLES APPENDIX B TABLE B l Average weekly body weights and t h e i r analyses of v a r i a n c e , t e s t 1 B2 Average growth r a t e s and t h e i r analyses of v a r i a n c e , t e s t . 1 B3 Average weekly body weights and t h e i r a nalyses of v a r i a n c e , t e s t 2 B4 Average growth r a t e s and t h e i r analyses of v a r i a n c e , t e s t 2 B5 Average weekly body weights and t h e i r a nalyses of v a r i a n c e , t e s t 3 B6 Average growth r a t e s and t h e i r analyses of v a r i a n c e , t e s t 3 B7 Average weekly body weights and t h e i r a nalyses of v a r i a n c e , t e s t 4 B8 Average growth r a t e s and t h e i r analyses of v a r i a n c e , t e s t 4 i x LIST OF TABLES APPENDIX C TABLE PAGE C l Average weekly body weights and t h e i r a nalyses of v a r i a n c e , t e s t 5 (males) 79 C2 Average growth r a t e s and t h e i r analyses of v a r i a n c e , t e s t 5 (males) 80 C3 Average weekly body weights and t h e i r a nalyses of v a r i a n c e , t e s t 5 (females) 81 C4 Average growth r a t e s and t h e i r analyses of v a r i a n c e , t e s t 5 (females) 82 C5 Average weekly body weights and t h e i r a nalyses of v a r i a n c e , t e s t 6 (males) 83 C6 Average growth r a t e s and t h e i r analyses o f v a r i a n c e , t e s t 6 (males) 84 C7 Average weekly body weights and t h e i r a nalyses of v a r i a n c e , t e s t 6 (females) C8 Average growth r a t e s and t h e i r analyses of v a r i a n c e , t e s t 6 (females) 8 6 X . LIST OF TABLES APPENDIX D TABLE PAGE Dl M u l t i p l e l i n e a r r e g r e s s i o n analyses f o r t e s t s 1 to 4, w i t h 3-week body weight as dependent v a r i a b l e D2 M u l t i p l e l i n e a r r e g r e s s i o n analyses f o r t e s t s 1 to 4, wit h 7-week body weight as dependent v a r i a b l e 8 9 D3 M u l t i p l e l i n e a r r e g r e s s i o n analyses f o r t e s t 5, w i t h 3-week body weight as dependent v a r i a b l e 90 D4 M u l t i p l e l i n e a r r e g r e s s i o n analyses f o r t e s t 6, wit h 3-week body weight as dependent v a r i a b l e 91 x i . LIST OF SYMBOLS A. = Surface area of an a r b i t r a r y s u r f a c e ' j ' of the 3 3 g 3 chamber. B_. = R a d i o s i t y of s u r f a c e ' j ' as d e f i n e d by equation [1] . F = Kata f a c t o r s u p p l i e d by the manufacturer of the Kata thermometer. G. .= C o n f i g u r a t i o n f a c t o r between s u r f a c e s ' j ' and ' i ' . Gg_^= C o n f i g u r a t i o n f a c t o r between the globe and s u r f a c e ' i ' I . = I n c i d e n t r a d i a n t energy on any s u r f a c e 1 j ' of the chamber, I . = I n c i d e n t r a d i a n t energy on the globe due to s u r f a c e ^ 1 1 i 1 of the chamber. I = T o t a l i n c i d e n t r a d i a n t energy on the globe from a l l s u r f a c e s of the chamber. T. = Absolute temperature of any s u r f a c e ' j ' of the chamber. Tg = Absolute temperature of the b l a c k globe. T g = Absolute mean r a d i a n t temperature. V = A i r speed i n the chamber as determined by the Kata thermometer. a & b Constants used i n the Kata equation [ 17 ] depending upon the type of the instrument, the c o o l i n g range and the a i r speed range to be measured. h = Convective heat t r a n s f e r c o e f f i c i e n t f o r the black globe thermometer depending upon the s i z e of the globe. q c = Convective heat l o s s or g a i n by the globe. q r = R a d i a t i v e heat l o s s or g a i n by the globe, t = Dry bulb temperature of a i r i n the chamber. x i i . t = Black globe temperature, g t = Mean r a d i a n t temperature. t = Mean temperature of the Kata thermometer depending m upon the c o o l i n g range of the instrument. 0 = C o o l i n g time of the Kata thermometer. £j = T o t a l h e m i s p h e r i c a l e m i s s i v i t y of s u r f a c e ' j 1 . e = T o t a l h e m i s p h e r i c a l e m i s s i v i t y of the b l a c k globe. a_. = T o t a l h e m i s p h e r i c a l a b s o r p t i v i t y of s u r f a c e 1 j ' . Pj = T o t a l h e m i s p h e r i c a l r e f l e c t i v i t y of s u r f a c e ' j 1 . a = Stefan-Boltzmann c o n s t a n t . BGT = Black globe temperature t MRT = Mean r a d i a n t temperature + t RHL = Radiant heat l o a d -»- I *•• g x i i i . ACKNOWLEDGEMENTS The author wishes to express h i s a p p r e c i a t i o n f o r a s s i s t a n c e i n t h i s study by: P r o f e s s o r L.M. S t a l e y , of the A g r i c u l t u r a l E n g i n e e r i n g Department, who p r o v i d e d guidance, a d v i c e , and encouragement d u r i n g t h i s r e s e a r c h p r o j e c t ; Dr. CW. Roberts, P o u l t r y Science Department; Dr. N.R. B u l l e y , Dr. E.O. Nyborg and P r o f e s s o r E.L. Watson, A g r i c u l - t u r a l E n g i n e e r i n g Department, f o r s e r v i n g on the r e s e a r c h committee and reviewing t h i s paper; Mr. A l Crompton, Foreman, and other s t a f f members of the P o u l t r y Farm who helped d u r i n g prehatch stage of t h i s study; Mr. J . Pehlke, E l e c t r o n i c T e c h n i c i a n , f o r counsel on e l e c - t r o n i c aspects o f the temperature c o n t r o l l e r s . Thanks i s a l s o extended to the N a t i o n a l Research C o u n c i l of Canada who pr o v i d e d f i n a n c i a l support f o r t h i s p r o j e c t . 1. INTRODUCTION Reduction i n the o v e r a l l h e a t i n g requirement of b r o i l e r houses can be accomplished by t a k i n g advantage of the thermal and o p t i c a l p r o p e r t i e s of i n f r a r e d r a d i a t i o n . Due to the d i r e c t i o n a l p r o p e r t y of thermal r a d i a - t i o n , the r a d i a n t energy can be t r a n s m i t t e d d i r e c t l y from the source of r a d i a t i o n to the b i r d s ; thus e l i m i n a t i n g the u s u a l process of p r e h e a t i n g l a r g e masses of a i r and the conveyance system a s s o c i a t e d with i t . By a v o i d i n g the n e c e s s i t y of h e a t i n g the a i r i n the b r o i l e r house a s u b s t a n t i a l r e d u c t i o n i n conductive heat l o s s through the s t r u c t u r e can be e f f e c t e d due to the decrease i n the temperature g r a d i e n t between the i n s i d e and o u t s i d e a i r . Another p r o p e r t y of thermal r a d i a t i o n of primary importance i s based on the f a c t t h a t the exchange of r a d i a n t energy between two bodies i s p r o p o r t i o n a l to the d i f f e r e n c e of the f o u r t h power of t h e i r r e s p e c t i v e a b s o l u t e temperatures (Stefan-Boltzmann Law). Because of t h i s f o u r t h power law, the amount of energy t h a t can be exchanged i s i n c r e a s e d s i g n i f i c a n t l y , w i t h s m a l l d i f f e r e n c e s i n s u r f a c e temperature. I n s t a n t heat i s the other p r o p e r t y of i n f r a r e d r a d i a t i o n of p r a c t i c a l importance compared to the r e l a t i v e l y long p e r i o d of time c o n v e n t i o n a l warm a i r systems r e q u i r e to b r i n g the temperature of the a i r i n the b u i l d i n g to a comfortable l e v e l f o r young c h i c k s . Even though i n f r a r e d r a d i a n t h e a t i n g systems would appear to be more economical than warm a i r systems, the e f f e c t s of such r a d i a t i o n on b i o l o g i c a l systems and a s s o c i a t e d e n v i r o n - mental parameters must be known b e f o r e r a d i a n t h e a t i n g systems can be wi d e l y adopted. U n f o r t u n a t e l y , l i m i t e d data are a v a i l a b l e about the e f f e c t s o f i n f r a r e d r a d i a t i o n on the growth of b i r d s and l e s s about t h e i r thermal s u r f a c e p r o p e r t i e s Consequently, the purpose of t h i s i n v e s t i g a t i o n was to study the e f f e c t s of i n f r a r e d r a d i a t i o n on b r o i l e r c h i c k s , u s i n g growth r a t e s as an index. The thermal r a d i a t i o n was from sources o p e r a t i n g a t temperatures of l e s s than 200°F (93°C). 3 . LITERATURE REVIEW Researchers i n the environmental aspects of p o u l t r y agree t h a t the brooding phase, hatch t o about t h r e e or f o u r weeks of age, i s the most important and most c r i t i c a l p e r i o d i n the l i f e o f the b i r d . The performance of the b i r d d u r i n g i t s m a t u r i t y i s mainly dependent upon i t s brooding phase h i s t o r y . Environmental f a c t o r s which are important f o r the comfort of the c h i c k s are not, as y e t , f u l l y d e f i n e d . These f a c t o r s may be c l a s s i f i e d , a c c o r d i n g to t h e i r nature, i n t o thermal, p h y s i c a l and s o c i o l o g i c a l . In most i n s t a n c e s , environmental f a c t o r s t h a t were found to i n f l u e n c e the comfort of the b i r d s were i n v e s t i g a t e d s e p a r a t e l y , thus, i g n o r i n g i n t e r a c t i o n s which may e x i s t between the simple f a c t o r s . The- e f f e c t s of a i r speed, a i r composition, n o i s e - and r a d i a t i o n have r e c e i v e d l i m i t e d a t t e n t i o n . Most of the a v a i l a b l e data are on the e f f e c t s of dry-bulb temperature and r e l a t i v e humidity on growth r a t e s of p o u l t r y ( S t a l e y e t a l . 1970) . Data on the e f f e c t of q u a l i t y and q u a n t i t y of l i g h t on b r o i l e r s are n e g l i g i b l e . McCluskey and A r s c o t t (1967) have i n v e s t i g a t e d the i n f l u e n c e of incandescent and i n f r a r e d lamps upon c h i c k s . They found t h a t body weights and f e e d c o n v e r s i o n of b i r d s , a t 56 days of age, r e a r e d under continuous l i g h t 4 . from 250 watt, c l e a r g l a s s , i n f r a r e d heat lamps d e l i v e r i n g a maximum of 600 f o o t candles (55.7 l u x ) , were s i g n i f i c a n t l y (P < 0.05) lower than b i r d s r e a r e d under continuous l i g h t from 250 watt, red g l a s s , i n f r a r e d heat lamps d e l i v e r i n g a maximum l i g h t i n t e n s i t y of 62 f o o t candles (5.8 l u x ) . Furthermore, the 8-week body weights of b i r d s r e a r e d under continuous l i g h t from 60 watt incandescent lamps w i t h a maximum i n t e n s i t y o f 1.2 f o o t candles (.11 lux) were h i g h e r , though not s t a t i s t i c a l l y s i g n i f i c a n t , than the 8-week body weights of b i r d s r e a r e d under red g l a s s heat lamps. Unfor- t u n a t e l y , we cannot conclude t h a t incandescent lamps are b e t t e r than i n f r a r e d lamps f o r the purpose of p o u l t r y r e a r i n g , because the lower body weight a s s o c i a t e d with the i n f r a r e d heat lamp treatments was probably due to tempera- ture d i f f e r e n c e r a t h e r than l i g h t s i n c e temperatures w i t h i n the pens were n e i t h e r c o n t r o l l e d nor measured. These temperatures were o b v i o u s l y d i f f e r e n t because the energy i n p u t to the pens were d i f f e r e n t , 250 watts compared to 60 watts. Because of the nature of t h i s experiment, i t i s probably s a f e r to conclude t h a t the red g l a s s heat lamps are b e t t e r than c l e a r g l a s s heat lamps f o r brooding c h i c k s . T h i s d i f f e r e n c e was due to ,the q u a l i t y r a t h e r than the q u a n t i t y of r a d i a t i o n . Longhouse and Garver (.1964) found l i t t l e d i f f e r e n c e between incandescent and f l u o r e s c e n t l i g h t s w i t h r e s p e c t to the p h y s i c a l c o n d i t i o n s of b r o i l e r s . 5. The i n f l u e n c e of l i g h t i n t e n s i t y was i n v e s t i g a t e d by Skoglund and Palmer (1962). They concluded t h a t b i r d s r e a r e d under a l i g h t i n t e n s i t y of 120 f o o t candles (11.1 lux) had s i g n i f i c a n t l y (P < 0.05) lower body weights than b i r d s r e a r e d under 10, 5, 2 and 0.5 f o o t candles (.93, .46, .19, .05 l u x ) . A l s o , they found no s i g n i f i c a n t d i f f e r e n c e among the low l i g h t i n t e n s i t y treatments but there was a tendency to a s m a l l i n c r e a s e of body weight with a decrease i n l i g h t i n t e n s i t y . Some p r e l i m i n a r y work was done on i n f r a r e d r a d i a t i o n brooding by Baker and Bywaters (1951), S t a l e y , Roberts and Crober (1967), Baxter, Maddox and S h i r l e y (1970). A l l of the mentioned i n v e s t i g a t o r s have used i n t h e i r experiments, i n d u s t r i a l i n f r a r e d heat lamps, h i g h temperature sources of r a d i a t i o n . These heat lamps were purchased from d i f f e r e n t manufacturers with d i f f e r e n t i n t e n s i t y and q u a l i t y of r a d i a t i o n . Baker and Bywaters (1951) have concluded t h a t the energy ..requirement f o r w i n t e r brooding was from 2 to 3 kWh per c h i c k w i t h continuous o p e r a t i o n of the heat lamps f o r the f i r s t 8 weeks. They have a l s o found t h a t the m o r t a l i t y r a t e f o r i n f r a r e d brooding ;was as low or lower than f o r other methods of brooding. No s i g n i f i c a n t d i f f e r e n c e s were found i n body weight or degree of f e a t h e r i n g between c h i c k s brooded under i n f r a r e d heat lamps and c h i c k s brooded w i t h o t h e r systems. F i n a l l y , these authors have found t h a t p u l l e t s 6 . r e a r e d w i t h i n f r a r e d r a d i a t i o n s t a r t e d to l a y 2 to 3 weeks e a r l i e r than t h e i r s i s t e r s brooded w i t h other systems. S t a l e y e t a l . (1967) have used a c l e a r g l a s s 250-watt heat lamp p l a c e d a t 24 inches (61 cm) above the ce n t r e of the pen. The pen was d i v i d e d i n t o two r a d i a t i o n l e v e l s w i t h approximate averages of 145 BTU/hr/sq f t (451 Wm~2) and 185 BTU/hr/sq f t (583 Wm~2) r e s p e c t i v e l y . The r e s u l t i n g 2-in b l a c k globe thermometer readings were 76.5°F (24.8°C)and 82°F (27.8°C) r e s p e c t i v e l y . They found s i g n i f i c a n t d i f f e r e n c e s (P < 0.05) i n body weights i n favour of the low r a d i a t i o n l e v e l . Baxter e t a l . (1970) have e s t a b l i s h e d comfort zones f o r c h i c k s a t d i f f e r e n t ages by c r e a t i n g a heat g r a d i e n t u s i n g three 375-watt i n d u s t r i a l i n f r a r e d heat lamps. The temperature g r a d i e n t was d i v i d e d i n t o equal c i r c u l a r zones with known e q u i v a l e n t b l a c k globe temperatures, and u s i n g as c r i t e r i o n of comfort the number of b i r d s r e s t i n g i n a s p e c i f i c zone. From the r e s u l t s of t h e i r experiments, the comfort e q u i v a l e n t globe temperature a t one week of age was about 79°F (26°C) and a t f i v e seeks of age i t was about 72°F (22°C) . 7 . EXPERIMENTAL DESIGN The e n t i r e experiment c o n s i s t e d of s i x t e s t s which may be d i v i d e d i n t o two c a t e g o r i e s or i n t o two sub-experiments. The f i r s t sub-experiment was designed p r i m a r i l y to study the e f f e c t of thermal r a d i a t i o n on growth r a t e of young b r o i l e r c h i c k s . T h i s sub-experiment was composed of fo u r t e s t s . In these t e s t s the independent v a r i a b l e of concern was the mean r a d i a n t temperature as c a l c u l a t e d from the b l a c k globe thermometer data; w h i l e the dependent v a r i a b l e was the weekly growth r a t e as c a l c u l a t e d from the weekly body weight d a t a . The f i r s t t h ree t e s t s c o n s i s t e d of t h r e e treatments each; a h i g h l e v e l of r a d i a t i o n , a low l e v e l of r a d i a t i o n and a c o n v e n t i o n a l brooding. The globe temperatures and the r e s u l t i n g r a d i a n t heat l o a d as a f u n c t i o n of the age of the b i r d s i n days from hatch, are i l l u s t r a t e d i n Table 1. For the h i g h l e v e l o f r a d i a t i o n the s t a r t i n g globe temperature was 88°F (31.1°C) dropping a t the r a t e of 3°F (1.7°C) every three days to a minimum of 70°F (21.1°C) on the n i n e t e e n t h day of age. For the low l e v e l of r a d i a t i o n , the s t a r t i n g globe temperature was,82°F (27.8°C) dropping a t the r a t e of 2°F (.1.1°C) every three days to a minimum of 70°F (21.1.°C) on the n i n e t e e n t h day of age. For both l e v e l s of r a d i a t i o n , the b i r d s were removed from the c o n t r o l l e d environment chambers on the t w e n t y - f i r s t day and t r a n s f e r r e d to separate pens i n the same house where TABLE 1. Black g l o b e temperature (BGT) and r a d i a n t heat l o a d (RHL) as per treatment and brooding p e r i o d f o r t e s t s 1, 2 and 3. Brooding P e r i o d (days) 1-3 4-6 7-9 10-12 13-15 16-18 19-21 High r a d i a t i o n l e v e l BGT (°F) 88 85 82 79 76 73 70 RHL (BTU h r " 1 f t " 2 ) 163 158 153 149 144 140 135 Low r a d i a t i o n l e v e l BGT (°F) 82 80 78 76 74 72 70 RHL (BTU h r " 1 f t " 2 ) 151 148 145 143 140 137 135 9 . the c o n v e n t i o n a l brooding treatment was l o c a t e d s i n c e the s t a r t of the t e s t . From the end of the t h i r d week to the t e r m i n a t i o n of the t e s t a t the end of the seventh week, the three t r e a t - ments were managed i n the same manner. TABLE 2. Black globe temperature (BGT) and r a d i a n t heat lo a d (RHL) as per brooding p e r i o d f o r t e s t 4. Brooding P e r i o d (days) 1-7 8-14 15-21 BGT (°F) 88 84 80 RHL (BTU/hr" 1 f t " 2 ) 163 156 151 The f o u r t h t e s t o f t h i s f i r s t experiment was designed to determine the e f f e c t of a lower r a t e of the b l a c k globe temperature drop as a f u n c t i o n of the age of the b i r d s . The f i n a l b l a c k globe temperature of 80°F (26.7°C) was chosen i n s t e a d of the 70°F (21.1°C) used d u r i n g the f i r s t three t e s t s of the experiment. T e s t 4 c o n s i s t e d of two treatments. One treatment s t a r t i n g at a globe temperature of 88°F (31.1°C) dropping 4°F (2.2°C) per week to 80°F (26.7°C) d u r i n g the t h i r d week of growth i n the chamber. The other treatment was a c o n v e n t i o n a l f l o o r brooding system u s i n g i n d u s t r i a l heat lamps. The globe temperature and the RHL f o r t e s t 4 as a f u n c t i o n of the brood- i n g p e r i o d are i l l u s t r a t e d i n Table 2. As mentioned e a r l i e r , the purpose of the previous 10. f o u r t e s t s , j u s t d e s c r i b e d , was to determine the e f f e c t of thermal r a d i a t i o n on the r a t e of growth of young c h i c k s . The second p a r t of the experiment or sub-experiment number two, was designed f o r three major purposes: 1) To t e s t the performance of a 300 c u b i c f e e t per min 3 —1 (8.5 m min ) a i r c o n d i t i o n i n g u n i t made by AMINCO- AIRE and i t s a d a p t a b i l i t y i n environmental c o n t r o l e x p erimentation with p o u l t r y . 2) To compare i n f r a r e d r a d i a t i o n brooding with warm a i r b r o o d i n g . 3) To study the e f f e c t of the environmental chambers. The second p a r t of t h i s experiment c o n s i s t e d of two t e s t s . In these t e s t s the independent v a r i a b l e of concern was the dry bulb temperature, w h i l e the dependent v a r i a b l e was the same as b e f o r e . Each t e s t c o n s i s t e d of three t r e a t - ments; chamber 1, chamber 2, and f l o o r b i r d s . The e n v i r o n - mental c o n d i t i o n s i n the two chambers were kept as c l o s e as p o s s i b l e with the a v a i l a b l e f a c i l i t i e s . The dry bulb temperature as a f u n c t i o n of the age of the c h i c k s i n days from hatch, f o r t e s t 5 and t e s t 6, are shown i n Table 3. For both t e s t s the s t a r t i n g dry b u l b temperature was 90°F (32.2°C) dropping a t the r a t e of 3°F (1.6°C) every three days to a minimum of 78°F (25.6°C) on the t h i r t e e n t h day f o r t e s t 5 and to a minimum of 72°F (22.2°C) on the n i n e t e e n t h day of age f o r t e s t 6. T e s t 5 and t e s t 6 were terminated on the TABLE 3. Dry-bulb temperature (°F) as per brooding p e r i o d f o r t e s t s 5 and 6. ( R e l a t i v e humidity = 50%) . Brooding P e r i o d (days) 1-3 4-6 7-9 10-12 13-15 16-18 19-21 T e s t 5 90.0 87.0 84.0 81.0 78.0 78.0 78.0 T e s t 6 90.0 87.0 84.0 81.0 78.0 75.0 72.0 t w e n t y - f i r s t day of age. During the e n t i r e i n v e s t i g a t i o n , the f l o o r b i r d s were re a r e d under i n d u s t r i a l heat lamps u s i n g a .conven t i o n a l brooding system. EXPERIMENTAL. MATERIAL AND PROCEDURE The experimental b i r d s f o r the f i r s t t e s t were U n i v e r s i t y of B r i t i s h Columbia New Hampshires, a s p e c i f i c g e n e t i c l i n e . T h i s c h o i c e of experimental m a t e r i a l was an attempt to reduce the experimental e r r o r thus i n c r e a s i n g the s e n s i t i v i t y of the experiment to the environmental e f f e c t of concern. During the f o l l o w i n g three t e s t s , U.B.C. b r o i l e r s , a l e s s homogeneous g e n e t i c l i n e than the New Hampshires, were used as experimental b i r d s . For the warm a i r experiment which i n c l u d e d t e s t s 5 and 6, the experimental b i r d s were commercial b r o i l e r s from J . J . Hambley H a t c h e r i e s (B.C.) L t d . , Ab b o t s f o r d . The eggs were hatched a t the U.B.C. p o u l t r y farm. For each of the t e s t s , one through f o u r , 120 male c h i c k s t h a t hatched on the t w e n t y - f i r s t day were randomly d i v i d e d and assign e d so t h a t a t o t a l of 40 b i r d s were i n each of the three treatments. A l l c h i c k s were completely dry on removal from the i n c u b a t o r and w i t h i n two hours r e c e i v e d a v a c c i n a t i o n f o r Marek 1s d i s e a s e . A f t e r the v a c c i n a t i o n and the assignment of the b i r d s to t h e i r treatments, they were wing banded f o r i d e n t i f i - c a t i o n , and weighed to the n e a r e s t gram. The subsequent weighings were randomized so t h a t no one order c o u l d be repeated on the next weighing. An a n t i b i o t i c was mixed with water f o r the f i r s t seven days of age. The b i r d s were fe d ad. li.bi.tam a standard b r o i l e r r a t i o n c o n t a i n i n g about 23 p e r c e n t p r o t e i n , 3.5 p e r c e n t f a t and 5 percent f i b r e . A l l b i r d s were i n d i v i d u a l l y weighed every week up to seven weeks of age. I n d i v i d u a l weekly body weights were punched on computer cards and the i n d i v i d u a l weekly growth r a t e s , the one to three week growth r a t e and the three to seven week growth r a t e were c a l c u l a t e d u s i n g the power func- t i o n r e l a t i o n s h i p g i v e n by Roberts (1964). The i n d i v i d u a l growth r a t e (r) f o r the p e r i o d between times t ^ and t.^ was computed by the f o l l o w i n g e x p r e s s i o n : LOG (=^) 1 r = H LOG {-M 1 where = body weight of b i r d a t time t ^ from c o n c e p t i o n Y 2 = body weight of b i r d a t time from c o n c e p t i o n t ^ and t ^ = age + 3 (on a weekly base) Once the t e s t was terminated, the b i r d s were k i l l e d and t h e i r sex v e r i f i e d by i n t e r n a l i n s p e c t i o n . The females were n e g l e c t e d from the a n l y s i s along with the b i r d s t h a t d i e d d u r i n g the seven weeks' t e s t . For t e s t 5 and t e s t 6, the same procedure was used w i t h the f o l l o w i n g m o d i f i c a t i o n s : The b i r d s were mixed i n s t e a d of a l l males. The t e s t s were terminated a t the end of t h r e e weeks of age i n s t e a d of seven weeks. And, f o r t e s t 6 o n l y , the d e n s i t y was reduced from 40 b i r d s to 36 b i r d s per treatment. At the end of each t e s t the b i r d s were k i l l e d and sexed by i n t e r n a l i n s p e c t i o n , then the males and females were analyzed s e p a r a t e l y . 15. DESCRIPTION OF EXPERIMENTAL EQUIPMENT 1. Thermal R a d i a t i o n Brooding Experiment The experimental system may be d i v i d e d i n t o two major systems: a) The c o n t r o l l e d environment chambers and t h e i r r a d i a n t heat sources. b) The a i r c o n d i t i o n i n g and conveying system. Two c o n t r o l l e d environment growth chambers o f s i m i l a r d e s i g n were used d u r i n g the e n t i r e i n v e s t i g a t i o n . Each chamber was c o n s t r u c t e d to house up to f o r t y b i r d s a t three weeks of age. The o v e r a l l i n s i d e dimensions of the chamber were 4X4 f e e t s u r f a c e area by 3 f e e t h i g h . The a i r e n t e r i n g the chambers was i n the same c o n d i t i o n f o r both chambers. T h i s a i r was kept a t the lowest dew-point temperature p o s s i b l e with the a v a i l a b l e a i r c o n d i t i o n i n g f a c i l i t i e s . T h i s was accom - p l i s h e d by c i r c u l a t i n g the r e t u r n a i r from the chambers over c h i l l e d water c o i l s then p a s s i n g i t through a f i n e water spray a t the same temperature as t h a t of the c o o l i n g c o i l s . The purpose of the spray chamber i s t w o f o l d . One, to ensure s a t u r a t i o n a t a c o n s t a n t dew-point temperature; two, to p a r t i a l l y c l e a n the r e t u r n a i r mixture from f i n e d u s t , ammonia and carbon d i o x i d e gases (Figure 1 ) . Throughout the thermal r a d i a t i o n experiment, t e s t s 1 through 4, the a i r l e a v i n g the a i r c o n d i t i o n i n g system and e n t e r i n g the growth chamber was s a t u r a t e d a t a c o n s t a n t 16 . FIGURE 1. SCHEMATIC OF THE AIR CONDITIONING SYSTEM USED WITH THE INFRARED RADIATION EXPERIMENT. H N M NOMENCLATURE A B C D E F G H I J K L M N 0 R e c i r c u l a t e d a i r from chambers F i b r e g l a s s f i l t e r Make-up a i r i n t a k e Damper f o r make-up a i r c o n t r o l C e n t r i f u g a l f a n (3 speeds) Fan e l e c t r i c motor C h i l l e d w ater c o o l i n g c o i l B a f f l e Hot water r e h e a t c o i l C o n d i t i o n e d a i r to chambers C o n t r o l l e d environment chambers Water r e c i r c u l a t i n g pump Water h e a t e r Water c h i l l e r Spray chamber 17 . temperature of about 45°F (7.2°C). T h i s s a t u r a t e d a i r was conveyed to the growth cham- bers through f l e x i b l e p l a s t i c d u c t s . The a i r entered the chambers near c e i l i n g l e v e l and exhausted below f l o o r l e v e l , then r e t u r n e d through f l e x i b l e ducts to a f i b r e g l a s s f i l t e r b e f o r e p a s s i n g over g a s - f i l l e d wet and dry bulbs of a tempera- t u r e r e c o r d e r c o n t r o l l e r . The r e t u r n a i r was then mixed with make up f r e s h a i r b e f o r e e n t e r i n g a 3-speed f a n to s t a r t a new c y c l e . The use of the low s a t u r a t i o n temperature of 45°F (7.2°C) was to make sure t h a t the young b i r d s got p r a c t i c a l l y a l l t h e i r heat requirement from the r a d i a n t heat source. The r a d i a n t heat source was composed of 4 r a d i a n t heat panels of 750 watts c a p a c i t y each, a t o t a l of 3 k i l o w a t t s per chamber. The r a d i a n t heat panels were l o c a t e d a t about 18 inches (45.7 cm) high from the wire f l o o r and p r o v i d e d almost f u l l coverage of the c e i l i n g s u r f a c e area o f the chambers. 2. Warm A i r Brooding Experiment The two c o n t r o l l e d environment chambers used with the thermal r a d i a t i o n experiment were a l s o used d u r i n g t h i s experiment, but wit h the r a d i a n t heat panels turned o f f . In order to keep the a i r i n the chambers a t some d e s i r e d s t a t e 3 -1 a 300 c u b i c f e e t per min (8.5 m min ) a i r c o n d i t i o n i n g u n i t was i n s t a l l e d , r e p l a c i n g the a i r c o n d i t i o n i n g system used w i t h the termal r a d i a t i o n experiment. 18. During t h i s warm a i r brooding experiment, t e s t s f i v e and s i x , the a i r was kept a t a c o n s t a n t r e l a t i v e humidity of 50 p e r c e n t , w h i l e the dry bulb temperature was v a r y i n g as s p e c i f i e d i n the experimental d e s i g n s e c t i o n , Table 3. S t a l e y and Roberts (1969) d e s c r i b e d i n d e t a i l the d e s i g n and development of the c o n t r o l l e d environment chambers used d u r i n g the i n v e s t i g a t i o n . DETERMINATION OF THE RADIANT HEAT LOAD DISTRIBUTION IN THE CHAMBER 1. R a d i o s i t y Method Assumptions In order to perform the r a d i a n t energy exchange a n a l y s i s among the d i f f e r e n t s u r f a c e s of the chamber, the f o l l o w i n g assumptions are made: 1. A l l the p a r t i c i p a t i n g s u r f a c e s of the chamber are grey, t h a t i s the emittance of anyone of the s u r f a c e s i s equal to i t s absorptance (e = a) f o r a l l wave- leng t h s f o r the range under study; 2. Each of the p a r t i c i p a t i n g s u r f a c e s i s i s o t h e r m a l . 3. The r a d i o s i t y of any s u r f a c e i s uniform along t h a t s u r f a c e . 4. The r a d i a t i o n emitted from any s u r f a c e i s d i f f u s e . 5. The r a d i a t i o n r e f l e c t e d from any s u r f a c e i s d i f f u s e . 6. The s u r f a c e s are separated by a non-absorbing, non- e m i t t i n g and n o n - s c a t t e r i n g medium. Assumption number two may be achieved by s u b d i v i - d i n g non-isothermal s u r f a c e i n t o s m a l l e r s u r f a c e s . The number of s u b d i v i s i o n s w i l l depend on the nature of the problem and the degree of accuracy d e s i r e d . The t h i r d assumption i s , p a r t i a l l y f u l f i l l e d by meeting assumption number two, but i n a d d i t i o n c o n s t a n t thermal p r o p e r t i e s of the s u r - face are r e q u i r e d . 20. For the purpose of p a r t i a l l y meeting the above mentioned assumptions, the w a l l s of the chamber were d i v i d e d i n t o t en s u r f a c e s , each one of which i s assumed i s o t h e r m a l . The development of the chamber and the i d e n t i f i c a t i o n number of the d i f f e r e n t s u r f a c e s are shown i n F i g u r e 2. Theory p a r t i c i p a t i n g s u r f a c e s . Surface ' j 1 i s r e c e i v i n g r a d i a t i o n from a l l s u r f a c e s of the chamber i n c l u d i n g i t s e l f i f s u r f a c e ' j ' i s concave. L e t t h i s t o t a l i n c i d e n t r a d i a t i o n on s u r f a c e ' j ' be I j . P a r t of t h i s i n c i d e n t r a d i a t i o n i s r e f l e c t e d from s u r f a c e ' j ' a t a r a t e of p. I , . The remaining i n c i d e n t 3 3 r a d i a n t energy i s absorbed by s u r f a c e ' j ' a t a r a t e o i j l j . A p o r t i o n of the absorbed r a d i a t i o n i s emitted back a t a r a t e EJOTJ and the remainder i s l o s t by cond u c t i o n through the chamber w a l l s and by c o n v e c t i o n to the a i r stream. There- f o r e , the t o t a l r a d i a n t energy l e a v i n g a s u r f a c e ' j ' per u n i t s u r f a c e area per u n i t time i s termed r a d i o s i t y . R a d i o s i t y (B) i s the sum of the r e f l e c t e d energy and the emitted energy. In e q u a t i o n form, the r a d i o s i t y of a s u r f a c e ' j ' may be s t a t e d as: L e t sur face ' j ' be any a r b i t r a r y s u r f a c e of the e.aT. + p • I 3 3 3 j [1] and f o r a grey-body (e=a). T h e r e f o r e p . = 1-e . 3 3 and equation [1] becomes, [2] globe loco Hons FIGURE 2. Development of the chamber showing surface i d e n t i f i c a t i o n number and the 9 locations of the globe. B i = e.aT. 4 + (1 - e.) I. [3] 3 D D J 3 But, I j , the t o t a l i n c i d e n t r a d i a t i o n on s u r f a c e ' j ' i s the sum of the r a d i a n t energy, r e f l e c t e d and emitted, l e a v i n g every one of the p a r t i c i p a t i n g s u r f a c e s of the chamber t h a t i s r e a c h i n g s u r f a c e 1 j 1 . Or i n equation form, n I . = E B i G • [4] 3 i = l ^ where, G. . i s the c o n f i g u r a t i o n f a c t o r between the a r b i t r a r y 3 - 1 s u r f a c e ' j ' and the s u r f a c e . ' i 1 . n = number of p a r t i c i p a t i n g s u r f a c e s making up the e n c l o s u r e . By i n s e r t i n g the v a l u e of I., i n t o the g e n e r a l r a d i o s i t y equation [1], we get, 4 n B • = e.oT •* + p E B i G . • . [5] 3 i = l J From the above d i s c u s s i o n i t i s c l e a r t h a t there are as many r a d i o s i t i e s as s u r f a c e s . T h e r e f o r e , an equation of the form of e q u a t i o n [5] may be w r i t t e n f o r each s u r f a c e . Thus, we o b t a i n a system of 'n' l i n e a r non-homogeneous a l g e b r a i c equations with 'n' unknown r a d i o s i t i e s . S o l u t i o n and R e s u l t s T h i s sytem of l i n e a r a l g e b r a i c equations may be w r i t t e n i n simple matrix form: A X - b [6] where A = matr i x of c o e f f i c i e n t s , b = column v e c t o r of co n s t a n t s , and X = column v e c t o r of unknowns. Our problem i s to f i n d the column v e c t o r of unknowns which r e p r e s e n t s the r a d i o s i t i e s , g i v e n the column v e c t o r of con- s t a n t s and the matr i x of c o e f f i c i e n t s . With some simple a l g e b r a i c m a n i p u l a t i o n , equation [5] may be changed to the matrix form: d - P l G i - i ) B l - P l G i - 2 B 2 - P l G i _ 3 B 3 - - p l G l - 1 0 B l 0 = £ 1 ° T 1 4 4 " p 2 G 2 - l B i + ( 1 ~ P 2 G 2 - 2 ) B 2 " P 2 G 2 - 3 B 3 _ ~ P2G2-10 B10 = e 2 a T 2 - p 1 0 G 1 0-l B r P 1 0 GlO _ 2 B 2 " P 1 0 G 1 0 - 3 B 3 ' - - + ( 1 - p l 0 G 1 0 - 1 0 ) B 1 0 = £ l 0 a T l To s o l v e the system of l i n e a r a l g e b r a i c equations f o r the ten unknown r a d i o s i t i e s , the s u r f a c e temperatures as w e l l as the c o n f i g u r a t i o n f a c t o r between each p a i r of s u r f a c e s i n the chamber must be known. A minimum of thr e e temperatures a t d i f f e r e n t l o c a t i o n s on each s u r f a c e of the chamber were measured. The. mean of the three or more measurements i s taken as the temperature of t h a t s p e c i f i c s u r f a c e . These means are i n c l u d e d i n Appendix A, Table A l along with the s u r f a c e a r e a , the m a t e r i a l and the assumed emittance of each s u r f a c e . The c o n f i g u r a t i o n f a c t o r s f o r a r e c t a n g u l a r enclos- ure are easy to c a l c u l a t e s i n c e only two b a s i c types of con- f i g u r a t i o n are presen t : 1. Opposite and equal p a r a l l e l r e c t a n g l e s , and 2. P e r p e n d i c u l a r r e c t a n g l e s with a common edge. Equations, t a b l e s and graphs used to determine the c o n f i g u r a t i o n f a c t o r s f o r these two common geometries are a v a i l a b l e i n most r a d i a t i o n heat t r a n s f e r t e x t books. The two equations used i n t h i s paper are given by S i e g e l and Howell (1972). For the two equal, p a r a l l e l , d i r e c t l y opposed r e c t a n g l e s , * G 1-2 T T X Y l+X + Y 1/2 + X /^ + Y2 a r c t a n X + Y A [7] l+X a r c t a n - (X a r c t a n X) - ( Y a r c t a n Y ) where X = a/c and Y = b/c. For the two f i n i t e r e c t a n g l e s of the same l e n g t h , having one common edge, and p e r p e n d i c u l a r to each other i — 1 ** G 1-2 1 TTX X a r c t a n — + Y a r c t a n X x 1 - / y2.„2 X + Y a r c t a n X' [8] 2„ + \ m { [ ( 1 + x ^ ^ : Y ^ ] [ x * < j ; + x y > ] ^ 2 ( I + X 2 + Y 2 ) 2 2 (l+X + Y ) 2 2 2  1 2 2 2 (l+X )(X + Y ) (1+ Y ) ( X + Y ) } * For d e f i n i t i o n of terms r e f e r to F i g u r e 3a For d e f i n i t i o n of terms r e f e r to F i g u r e 3b  With the use of equations [7] and [8] along w i t h the symmetry r e l a t i o n s , the f l u x - a l g e b r a or a n g l e - f a c t o r a l g e b r a , and the c o n f i g u r a t i o n f a c t o r r e c i p r o c i t y r u l e ; a l l the one hundred c o n f i g u r a t i o n f a c t o r s r e q u i r e d can e a s i l y be determined. The c o n f i g u r a t i o n f a c t o r r e c i p r o c i t y r u l e i s The c a l c u l a t i o n s f o r c o n f i g u r a t i o n f a c t o r s use the f l u x a l g e b r a method which has been e x p l a i n e d by Sparrow and Cess (1970) . Using the dimensions o f F i g u r e 2 and the above equations and r u l e s , the c o n f i g u r a t i o n f a c t o r s were c a l c u l a t e d and the r e s u l t s are shown i n Appendix A, Table A2. The sum of a l l the c o n f i g u r a t i o n f a c t o r s from any s u r f a c e ' j 1 to a l l the s u r f a c e s making up the e n c l o s u r e must equal u n i t y , or i n e quation form: n E G. . = 1.0. [10] i = l 3 1 T h i s sum i s a l s o shown i n Table A2 as a check f o r e r r o r s i n c a l c u l a t i n g c o n f i g u r a t i o n f a c t o r s . With these c o n f i g u r a t i o n f a c t o r s and the s u r f a c e temperatures, the system of l i n e a r nonhomogeneous equations can be s o l v e d on the d i g i t a l computer. The m a t r i x of c o e f f i c i e n t s and the column v e c t o r of c onstants are shown i n Appendix A, T a b l e A3. The s o l u t i o n of the m a t r i x was o btained by u s i n g the Gaussian e l i m i n a t i o n method wi t h p a r t i a l p i v o t i n g . The r e s u l t s are summarized i n Table 4. TABLE 4. Computer output f o r the v a l u e of the r a d i o s i t y (B) i n BTU hr f t f o r the 10 s u r f a c e s of the chamber as s p e c i f i e d i n F i g u r e 2. Surface R a d i o s i t y Surface R a d i o s i t y 1 210.96 6 166.07 2 152.66 7 151.38 3 172.84 8 166.85 4 165.58 9 174 .48 5 173.44 10 166.29 2. Black Globe Thermometer Method Temperature of r a d i a n t heat panels Temperature r e g u l a t i o n of the r a d i a n t heat panels was c r i t i c a l because of the f o u r t h power law of r a d i a t i o n 4 (q <x T ) . An on-off Honeywell c o n t r o l l e r was t e s t e d f i r s t ; i t was found t h a t there were f l u c t u a t i o n s up to 7°F (4°C) i n the s u r f a c e temperatures of the heat p a n e l s . In order to minimize these f l u c t u a t i o n s , the on - o f f c o n t r o l l e r was r e p l a c e d by an e l e c t r o n i c p r o p o r t i o n a l c o n t r o l l e r with r e s i s t a n c e type temperature sensor cemented to the s u r f a c e of the r a d i a n t heat p a n e l . With t h i s p r o p o r t i o n a l c o n t r o l l e r a maximum f l u c t u a t i o n of 4°F (2.2°C) was encountered. 28 . The l o c a t i o n o f t h e t e m p e r a t u r e s e n s o r on t h e h e a t p a n e l was d e t e r m i n e d by m e a s u r i n g t h e t e m p e r a t u r e on i t s s u r f a c e a t n i n e l o c a t i o n s s i m u l t a n e o u s l y . The m easured d i f f e r e n c e i n t e m p e r a t u r e between l o c a t i o n s were w i t h i n 2°F ( 1 ° C ) . S i n c e t h e s e d i f f e r e n c e s were w e l l w i t h i n t h e t e m p e r a - t u r e f l u c t u a t i o n r a n g e , t h e l o c a t i o n o f t h e s e n s o r on t h e h e a t p a n e l was i m m a t e r i a l . Mean R a d i a n t T e m p e r a t u r e (MRT), R a d i a n t H e a t L o a d (RHL) and B l a c k G l o b e T e m p e r a t u r e (BGT). The MRT, l i k e t h e e f f e c t i v e t e m p e r a t u r e , t h e e q u i v a l e n t t e m p e r a t u r e and s i m i l a r t e r m s , i s an e n v i r o n m e n t a l i n d e x r a t h e r t h a n a r e a l t e m p e r a t u r e . T h e r e f o r e , l i k e o t h e r t h e r m a l e n v i r o n m e n t a l i n d i c e s , i t c a n n o t be m easured d i r e c t l y . The MRT i s a measure o f t h e combined e f f e c t s o f t h r e e o f t h e m a i n e n v i r o n m e n t a l f a c t o r s , namely a m b i e n t a i r t e m p e r a t u r e , a i r v e l o c i t y and t h e r m a l r a d i a t i o n . The MRT c a n o n l y be computed f r o m t h e b l a c k g l o b e t h ermometer d a t a . Few p a p e r s have b e e n w r i t t e n on t h e t h e o r y o f t h e b l a c k g l o b e t h e rmometer and i t s a p p l i c a t i o n t o t h e r m a l e n v i r o n m e n t a l s t u d i e s i n a g r i c u l t u r e and o t h e r f i e l d s . Among t h e s e , B e d f o r d and Warner (1934), Bond and K e l l y ( 1 9 5 5 ) , P e r e i r a e t a l . (1966) and P a r k e r e t a l . (1967) a r e n o t a b l e e x a m p l e s . The b a s i c b l a c k globe thermometer c o n s i s t e d of a temperature sensor p l a c e d a t the c e n t r e o f a hollow, blackened, copper sphere. P e r e i r a e t a l . (1966) c o n s i d e r e d u s i n g a t a b l e t e n n i s b a l l as a b l a c k globe thermometer; they found t h a t the response time of the b l a c k globe thermometer made of a t a b l e t e n n i s b a l l was c o n s i d e r a b l y f a s t e r than t h a t of the copper b l a c k globe thermometer. The s e l e c t i o n of the s i z e of the sphere, the type and s i z e of the temperature sensor i s dependent on the a p p l i c a - t i o n and the response time d e s i r e d . The e f f e c t of the diameter of the sphere on the b l a c k globe temperature was d i s c u s s e d by Bond and K e l l y (1955) and Bedford and Warner (1934) . Parker e t a l . (1967) d i s c u s s e d the e f f e c t of thermo- couple wire s i z e on the b l a c k globe thermometer r e a d i n g ; they a l s o estimated the pe r c e n t e r r o r due to heat conduction f o r v a r i o u s wire s i z e s . The s i z e of the globe was s e l e c t e d u s i n g the s u r f a c e area to volume r a t i o c r i t e r i o n . For young c h i c k s , the s u r f a c e area to volume r a t i o decreases w i t h age from about 2.6 a t hatch to 0.8 a t 7 weeks of age. When the e q u i v a l e n t diameter o f the b i r d i s taken as the diameter o f the sphere having the same s u r f a c e a r e a , the 2 i n c h (.5 cm) diameter globe w i l l have approximately the same s u r f a c e area to volume r a t i o as a ha t c h i n g b i r d . T h e r e f o r e , the 2 i n c h (5 cm) diameter b l a c k globe thermometer, p a i n t e d w i t h two coats of f l a t b l a c k l a c q u e r , was chosen as the standard to c o r r e l a t e the growth 30 . r a t e of young b r o i l e r s to the BGT. Iron-constantan thermocouples were used to measure the a i r and globe temperatures. The s i z e of the thermocouples (24 gauge) i n t h i s experiment was not c r i t i c a l because of the s t e a d y - s t a t e c o n d i t i o n of the environmental chambers. For a b e t t e r understanding of how the MRT i s r e l a t e d to the b l a c k globe temperature, i t i s h e l p f u l to examine the f i n a l r e s u l t of the theory of the b l a c k globe thermometer. I f i t i s assumed t h a t the globe i s a t e q u i l i b r i u m w i t h i t s surroundings and i t i s under steady s t a t e c o n d i t i o n s , and i f conduction through the thermocouple wires and the support i s n e g l e c t e d , then the heat l o s s or g a i n by r a d i a t i o n must equal the heat l o s s o r g a i n by c o n v e c t i o n , (q^ = q „ ) , thus H C ^ % " t a ) = £ g O ( T s 4 - T g4) [11] S o l v i n g the above eq u a t i o n f o r the mean r a d i a n t temperature, T s , i n degrees Rankine, we get, T = 100 s h C „0.5 — 4 - ^ 4 - 4 — V ^g " V + <1*0> 0 . 25 [12 ] and i n degrees F a r h e n h e i t MRT = T g - 459.69 In the above e q u a t i o n s , the c o n v e c t i v e heat t r a n s f e r c o e f f i c i e n t (h ) f o r d i f f e r e n t diameters of the globe are g i v e n by the ASHVE Research T e c h n i c a l A d v i s o r y Committee on 31 Instruments (1942). For the 2 i n c h diameter globe, they suggest the v a l u e of 0.202. A l s o , i n the above equations, the emmissiv- i t y of the b l a c k globe may be taken as t h a t of the f l a t b l a c k lacquer p a i n t ( e = .95). By equation [12] i t may be seen t h a t i n order to compute the MRT, measured v a l u e s of the globe temperature, the a i r temperature and the a i r v e l o c i t y near the globe are r e q u i r e d . A l s o , i t may be seen from equation [12] t h a t the MRT approaches the BGT i f the d i f f e r e n c e between BGT and a i r temperature approaches zero or the v e l o c i t y of the a i r approaches zero (calm environmental c o n d i t i o n s ) . In e i t h e r case e q u a t i o n [12] becomes 4 4 % e a (T - T ) = O h o ] g s g i J which i m p l i e s t h a t , T = T . s g The MRT i s a measure of the e q u i v a l e n t temperature of the surrounding s u r f a c e s with which the animals are exchang- ing r a d i a n t energy. A l s o , the MRT i s a d i r e c t i n d i c a t o r of the r a d i a n t energy i n c i d e n t on the animals. T h i s i n c i d e n t r a d i a t i o n , r e f e r r e d to as r a d i a n t heat l o a d (RHL) by Bond and K e l l y (1955), i s p r o p o r t i o n a l t o the f o u r t h power of the MRT, or 4 RHL = a T g . [14 ] The MRT may be c a l c u l a t e d u s i n g equation [12] or read d i r e c t l y from the nomograph, F i g u r e 4. DIFFERENCE BETWEEN GLOBE .AND AIR TEMPERATURE ( t g - t j , °F. a H r 1 c . o v • TJ co cn M tn o z c HfJ O » ~ 2 tt tn o w a s jo o > S 13 tn a cn S3- o ?J f o I H z D H > tt W o o sr rc i ll II o o o. Ul M \ \ \ \ V \ \ \ \ \ \ \ \ \ \ \ \ \ s \ \ \ \ \ •2 v > S. ^ (to n o 00 o o! i l l \ Co f MEAN PADT.ANT TEMPERATURE, °F In order to check the v a r i a t i o n s i n RHL i n s i d e the chamber the MRT was determined a t nine l o c a t i o n s * of the f l o o r s u r f a c e area. The c e n t r e of the globe was kept a t about 13 inches (33 cm) from the heat panels d u r i n g a l l the nine measure- ments. The a i r temperature was measured a t about 2 inches (5 cm) from the globe by a s h i e l d e d i r o n - c o n s t a n t a n thermo- couple. The c o o l i n g r a t e of a Kata thermometer was used to determine the a i r v e l o c i t y near the b l a c k globe at each l o c a - t i o n . The Kata thermometer was chosen because of the low v e l o c i t y range encountered i n the chamber. The equation used to r e l a t e the c o o l i n g time to the a i r v e l o c i t y was g i v e n by Bruce (1960) as, " 2 I - a /b where V V F 0 t F/0 m t = (t - t ) m a a i r v e l o c i t y i n fpm Kata f a c t o r average c o o l i n g time i n sees mean temperature of the Kata thermometer i n °F [15] a i r temperature i n °F a and b = c o n s t a n t s . The Kata f a c t o r F i s s u p p l i e d w i t h each thermometer by the manufacturer. The F f a c t o r f o r the n o n - s i l v e r e d thermometer employed i n t h i s experiment was 473 ( c o o l i n g range 100 - 95°F) The v a l u e s of a and b as w e l l as the mean tempera- t u r e , t , are gi v e n by Bruce (1960) f o r low v e l o c i t i e s * Refer to F i g u r e 2, on page 21. (< 180 fpm). In t h i s experiment the v e l o c i t y equation 0.111 "" 2 V (97.7-ta) 0.0158 L was used. R e s u l t s The computed a i r v e l o c i t i e s , mean r a d i a n t tempera- t u r e s , and r a d i a n t heat loads f o r the nine l o c a t i o n s are t a b u l a t e d i n Appendix A, Table A6, along w i t h the measured a i r temperatures and globe temperatures f o r a constant heat panel temperature of 136°F (58°C). A c o r r e c t i o n was r e q u i r e d to account f o r the s i z e of the globe. Bond and K e l l y (1955) have shown t h a t there i s an i n c r e a s e i n globe temperature w i t h i n c r e a s e i n globe s i z e . They a l s o i n d i c a t e d t h a t the 6 and 8 i n c h (15.2- 20.3 cm) globes gave the c l o s e s t v a l u e s to the s p h e r i c a l radiometer r e a d i n g s . A maximum temperature d i f f e r e n c e of 7°F (3.8°C) between the 2 and 6 i n c h globe thermometer was r e p o r t e d . The e q u i v a l e n t r a d i a n t heat l o a d v a l u e s c o r r e c t e d to the standard 6 i n c h (15.2 cm) diameter b l a c k globe thermometer are shown i n the l a s t row of Table A6. 3. Comparison of Radiant Heat Load R e s u l t s Obtained by the R a d i o s i t y Method and the Black Globe Thermometer Method In order to compare the r e s u l t s of the two methods i t i s necessary t o c a l c u l a t e the i n c i d e n t r a d i a t i o n (RHL) on the globe u s i n g the p r e d i c t e d r a d i o s i t i e s of the chamber w a l l s and heat p a n e l s . T h i s i n c i d e n t r a d i a t i o n i s the sum of the r a d i a t i o n streaming away from each s u r f a c e of the chamber t h a t i s r e a c h i n g the globe. L e t t h i s i n c i d e n t r a d i a n t energy be termed I , then i n equation form, n I = I G.G . (n = 10) [17] g i = 1 i g - i where n Z G . = 1 i = l G . = c o n f i g u r a t i o n f a c t o r between the Q — i y globe and s u r f a c e ' i 1 of the chamber. The c o n f i g u r a t i o n f a c t o r s between the globe and the ten s u r f a c e s of chamber f o r each of the nine l o c a t i o n s * of the globe were determined by the use of equation [18], along with the symmetry r e l a t i o n s and f l u x - a l g e b r a . G . = -.— a r c s i n [18] 4u r 2 2 2 2 l+X +Y +X Y The c o n f i g u r a t i o n f a c t o r s f o r the globe a t any l o c a t i o n (A^, A^, A^, B.̂ , B^, B^, C^, C^, C^) to any of the ten s u r f a c e s of the chamber are t a b u l a t e d i n Appendix A,Table A4 Using equation [17] and the c o n f i g u r a t i o n f a c t o r s of Table A4, the t h e o r e t i c a l i n c i d e n t r a d i a t i o n on the globe at each l o c a t i o n may be c a l c u l a t e d . The r e s u l t s are shown i n * Appendix A ** For d e f i n i t i o n of terms r e f e r to F i g u r e 3c, Appendix A, Table A5. For the purpose of comparison, the p r e d i c t e d and experimental r a d i a n t heat l o a d v a l u e s f o r the nine l o c a t i o n s of the globe i n the chamber, are reproduced i n Table 5. The experimental v a l u e s of the i n c i d e n t r a d i a n t energy of the globe (RHL), u s i n g the bl a c k globe thermometer method, are taken from Table A6*; and the p r e d i c t e d v a l u e s u s i n g the r a d i o s i t y method are taken from Table A5*. Table 5 shows t h a t the p r e d i c t e d mean r a d i a n t heat -1 -2 -2 load i n the chamber was 8.8 BTU hr f t (27.75 Wm ) highe r than the experimental mean v a l u e . T h i s i m p l i e s , i f the r a d i o s i t y method was to be used to des i g n such environmental chambers f o r a s p e c i f i c r a d i a n t heat l o a d on c e r t a i n s u r f a c e of the en c l o s u r e , then the a c t u a l mean r a d i a n t heat l o a d , as determined by the b l a c k globe thermometer would be about 5 percent lower than the r e q u i r e d v a l u e . For most d e s i g n purposes t h i s e r r o r i s ac c e p t a b l e ; t h e r e f o r e , the r a d i o s i t y method i s a v a l u a b l e d e s i g n t o o l , i f a d i g i t a l computer i s a c c e s s i b l e . The main advantage of the r a d i o s i t y method i s probably the a b i l i t y to change the p r o p e r t i e s of the s u r f a c e s as w e l l as the shape o f the s t r u c t u r e , i n order to o b t a i n an even r a d i a n t energy d i s t r i b u t i o n with the most e f f i c i e n t r a d i a n t energy u t i l i z a t i o n . In the presen t experiment the p r e d i c t e d maxiumum d i f f e r e n c e i n r a d i a n t heat l o a d between l o c a t i o n s , a t the f l o o r l e v e l of the chamber, was 4.0 BTU h r " 1 f t " 2 (12.6 Wm"2), as -1 -2 compared to the measured maxiumum va l u e of 6.1 BTU hr f t (19.2 Wm~2). * Appendix A TABLE 5. P r e d i c t e d and experimental RHL (BTU hr f t ) d i s t r i b u t i o n i n the environmental chamber. L o c a t i o n of the globe i n the chamber A l A2 A3 BI B2 B3 C l C2 C3 P r e d i c t e d 170 .9 171.6 171.0 174. 0 174 .9 174 .2 173 .3 174 .4 173 . 5 E x p e r i - mental 163 .8 161.8 166.2 162. 7 163 .3 167 .9 163 .6 163 .3 166 .3 D i f f e r e n c e 7 .1 9.8 4.8 11. 3 11 .6 6 .3 9 .7 11 .1 7 .2 % E r r o r 4 .3 6.0 2.8 6. 9 7 .1 3 .7 5 .9 6 .7 4 .3 P r e d i c t e d mean RHL i n the chamber = 173.1 BTU hr f t = 545.88 Wm-2 -1 -2 Experimental mean RHL i n the chamber = 164.3 BTU hr f t = 518.13 Wm-2 P r e d i c t e d maximum d i f f e r e n c e between l o c a t i o n s i n the chamber = 4,0 BTU hr 1 f t - 2 (12.6 Wm-2) Experimental maximum d i f f e r e n c e between l o c a t i o n s i n the chamber =6.1 BTU h r - 1 f t - 2 (19.2 Wm"2) Maximum d i f f e r e n c e between experimental and p r e d i c t e d RHL s 11.6 BTU h r - 1 f t " 2 (36.58 Wm"2) Mean d i f f e r e n c e between experimental and p r e d i c t e d RHL = 8.8 BTU h r ^ 1 f t " 2 (27.75 Wm-2) Mean p e r c e n t e r r o r = 17 3.1 - 164.3 x 1 0 Q _ 5 _ 3 % 164.3 DATA ANALYSIS 1. General Models (a) A n a l y s i s of v a r i a n c e of the experimental data The weekly body weights and growth r a t e s were analyzed u s i n g the f o l l o w i n g s t a t i s t i c a l model: Y i j = y + d ± + e ± j [19] where, Y^. = the weekly body weight or growth r a t e of -1 b i r d ' j ' i n treatment ' i ' , y = the t r u e p o p u l a t i o n mean, d^ = the f i x e d e f f e c t of treatment ' i ' , e . . = independent random normal d e v i a t e s w i t h 1-1 mean zero and v a r i a n c e a e 2 , i = treatments = 1-3 f o r a l l t e s t s except f o r t e s t 4, where i = 1, 2 and j = 1 - = i n d i v i d u a l s w i t h i n treatments. In order to perform the a n a l y s i s of the data f o r the case of unequal number of o b s e r v a t i o n s per treatment, a F o r t r a n program was w r i t t e n f o l l o w i n g the procedure of a n a l y s i s o u t l i n e d by Brownlee (1960), chapter 10. For the s i n g l e degree of freedom c o n t r a s t s , and the e s t i m a t i o n of the confidence i n t e r v a l s , the S c h e f f e ' s method was used, Brownlee (1960). The c o n f i d e n c e i n t e r v a l f o r any c o n t r a s t 9, where k e = z c, y. 120] i = i 1 with an estimated v a r i a n c e 2 k V[@] = a e z z ( C i / r i i ) [21] i = l 39 k and w i t h the r e s t r i c t i o n , E = 0. [22] i = l Then, the S c h e f f e ' s l i m i t s f o r the c o n t r a s t are + S (V [ 9 ] ) 0 - 5 r 2 3 ] where, S 2 = (k-1) F±_a (k-1, v) [24] k = number o f treatments, v = degrees of freedom f o r the e r r o r term, (b) Regression a n a l y s i s of the experimental data M u l t i p l e l i n e a r r e g r e s s i o n was used to determine the 2 c o e f f i c i e n t of d e t e r m i n a t i o n , R . Three mathematical models were f i t t e d to the i n f r a r e d brooding experimental d a t a . These models are: i) Y = a Q + h1 X]_ + b 2 X 2 + b 3 X 3 [25] where, Y = 3-week body weight i n grams, Xj_ = 1-week body weight i n grams, X 2 = 1-2 week growth r a t e , X-j = 2^3 week growth r a t e and a , b , b„ and b, are m u l t i p l e l i n e a r r e g r e s s i o n c o e f f i c i e n t s o 1 I ~> where, i i ) Y 1 = a Q + b{ X-L + b' X 4 [26] I Y 1 = 3--week body weight i n grams, X^ = l^week body weight i n grams, X^ = 1--3 week growth r a t e , and a^, b j and b^ are m u l t i p l e l i n e a r r e g r e s s i o n c o e f f i c i e n t s . 40. i i i . ) Y" ~ + X x + X 2 + X 5 [27] where, y" f= 7^-week body weight i n grams, X-̂  = 1-week body weight i n grams, X 2 ?= 1^3 week growth r a t e , X^ = 3-7 week growth r a t e , and a", b", b o and b, are m u l t i p l e l i n e a r r e g r e s s i o n c o e f f i c i e n t s , o For the warm a i r brooding experimental d a t a , only the f i r s t two models were used, s i n c e the experiment was terminated at three weeks of age r a t h e r than seven weeks. 2. R e s u l t s and D i s c u s s i o n of the Analyses of Var i a n c e a) I n f r a r e d brooding experiment TEST 1: New Hampshires The average weekly body weights and t h e i r analyses of va r i a n c e are i n c l u d e d i n Appendix B, Table BI. The average weekly growth r a t e s as w e l l as the average growth r a t e s f o r the 1 to 3-week p e r i o d and the 3 to 7-week p e r i o d with t h e i r analyses of v a r i a n c e are i n c l u d e d i n Appendix B, Table B2. In the above mentioned two t a b l e s , the treatments were as f o l l o w s : F l o o r ( c o n v e n t i o n a l heat lamp b r o o d i n g ) . Chamber 1 (low r a d i a t i o n l e v e l b r o o d i n g ) . Chamber 2 (high r a d i a t i o n l e v e l b r o o d i n g ) . The analyses of v a r i a n c e of average weekly body weights (Table B l (b)) show t h a t f o r the f i r s t t h ree weeks of age, the average weekly body weights of b i r d s r e a r e d i n the two chambers 41. were s i g n i f i c a n t l y h i g h e r (probably < 0.01) than the average weekly body weights of b i r d s r e a r e d on the f l o o r . Table BI, a l s o i n d i c a t e s t h a t there was no s i g n i f i c a n t d i f f e r e n c e i n average weekly body weights between b i r d s brooded under the high l e v e l of thermal r a d i a t i o n (chamber 2) and b i r d s brooded under the low l e v e l of r a d i a t i o n (chamber 1). However, the average 7-week body weight of b i r d s brooded i n the high r a d i a t i o n l e v e l chamber was 25 grams hig h e r (though s t a t i s t i c a l l y n o n - s i g n i f i c a n t ) than t h a t of b i r d s brooded i n the low r a d i a t i o n l e v e l chamber. The f a i l u r e of the a n a l y s i s to d e t e c t the above d i f f e r e n c e was due to the ^random v a r i a t i o n s which accounted f o r more than 9 8 percent of the t o t a l sums of squares. Furthermore, the analyses of v a r i a n c e of average weekly body weights (Table B l (b)) i n d i c a t e s t h a t the d i f f e r e n c e i n average weekly body weights, between b i r d s brooded i n chambers and b i r d s brooded on the f l o o r , became n o n - s i g n i f i c a n t d u r i n g the l a t e r weeks of the t e s t (4 to 7 weeks), when the c h i c k s r e a r e d i n the chamber f o r the f i r s t three weeks of age were t r a n s f e r r e d to the f l o o r . The f a i l u r e of the b i r d s brooded i n the chambers to m a i n t a i n t h e i r advantage i n body weights over the f l o o r b i r d s , i m p l i e s t h a t they s u f f e r e d a d e p r e s s i o n i n growth r a t e . T h i s d e p r e s s i o n s t a r t e d as e a r l y as the second week of growth as i n d i c a t e d by the analyses of v a r i a n c e of average growth r a t e s (Table B2 ( b ) ) . I t i s important to n o t i c e the h i g h l y s i g n i f i c a n t average d i f f e r e n c e i n the f i r s t week growth r a t e i n favour of the c h i c k s r e a r e d i n the chambers. The average f i r s t week growth r a t e s were 2.62 and 1.9 5 f o r chambers and f o r f l o o r b i r d s , r e s p e c t i v e l y (Table B2). But, d u r i n g the growth p e r i o d s (1 to 3) and (3 to 7) weeks, the f l o o r b i r d s had s i g n i f i c a n t l y h i g h e r ( p r o b a b i l i t y < 0.01) growth r a t e s than the corres p o n d i n g growth r a t e s f o r b i r d s r e a r e d i n the chambers. Even though the average growth r a t e of b i r d s brooded i n the chambers was 2.77 compared to 3.0 8 f o r f l o o r b i r d s f o r the same p e r i o d , the b i r d s r e a r e d i n chambers f i n i s h e d w i t h a h i g h l y ' s i g n i f i c a n t average 3-week body weight over f l o o r b i r d s . The h i g h e s t d e c l i n e i n growth r a t e f o r b i r d s i n the chambers was du r i n g the 3 to 4-week p e r i o d . T h i s p e r i o d corresponded to the t r a n s f e r of the young c h i c k s from the chambers to the f l o o r . The average growth r a t e s f o r the 3 to 4-week p e r i o d were 2.38 and 2.67 f o r chamber and f l o o r b i r d s , r e s p e c t i v e l y . The cause of the r e d u c t i o n i n growth r a t e d u r i n g the 3 to 4-week p e r i o d was due to the sudden environmental change from chambers to f l o o r . However, i t seems t h a t a f t e r a p e r i o d of a c c l i m a t i z a - t i o n o f one week, the b i r d s , which have been t r a n s f e r r e d from the chambers to the f l o o r , a d j u s t e d to the new environment. T h i s adjustment to the new environment i s i n d i c a t e d by the equal average weekly growth r a t e s d u r i n g the growth p e r i o d between 4 and 7 weeks, (Table B2).. The e q u a l i t y of weekly growth r a t e s d u r i n g the 4 to 7-weeks p e r i o d i m p l i e s t h a t the s i g n i f i c a n c e of the d i f f e r e n c e i n the 3 to 7-week p e r i o d growth r a t e i n favour of the f l o o r b i r d s , was mainly due to the s i g n i f i c a n t d i f f e r e n c e i n the 3 to 4-week growth r a t e . The high r e d u c t i o n i n growth r a t e d u r i n g the 3 to 4-week p e r i o d i s an i n d i c a t i o n t h a t the t r a n s f e r o f b i r d s from the chambers to the f l o o r was c r i t i c a l . In the subsequent t e s t s , care was taken to minimize p h y s i c a l and environmental s t r e s s e s d u r i n g the t r a n s f e r p e r i o d . The cause of the low growth r a t e , d u r i n g the second and t h i r d week of growth of b i r d s i n the two chambers compared to f l o o r b i r d s (Table B2), remains to be i n v e s t i g a t e d . The c o n f i d e n c e i n t e r v a l f o r the c o n t r a s t , chamber 1 and chamber 2 b i r d s versus f l o o r b i r d s may be estimated d u r i n g S c h e f f e ' s method. In equation form the c o n t r a s t may be expressed as, / \ / \ e = \i1 + y 2 - 2y 3 where, ^1' ^2' a n c ^ ^3 a r e e s t i m a t e s °f the tr u e mean of chamber 1, chamber 2, and f l o o r b i r d s r e s p e c t i v e l y . For the 1-week body weight, we have 0 = 89 + 89 - 2(74) = 30 grams, with an estimated v a r i a n c e V V [0] = [ ( l ) 2 '+ ( l ) 2 + (-2) 2] - 16.33 By equation [24], S 2 = 6.24; then, by equation [23], the 95 percent confidence l i m i t s a r e : 9 = 3 0 + 1 0 grams. S i m i l a r l y f o r the 2-week body weight we get, 9 = 3 6 + 2 1 grams, and, f o r the 3-week body weight, 9 = 3 5 + 3 3 grams. The 95 percent c o n f i d e n c e l e v e l l i m i t s f o r the d i f f e r e n c e i n weekly body weights between the hig h r a d i a t i o n l e v e l (chamber 2) and the c o n v e n t i o n a l brooding ( f l o o r ) treatments, may be c a l c u l a t e d i n a s i m i l a r manner. We have the c o n t r a s t , 9 = u 2 - -u 3. For the 1-week body weight, 9 = 1 5 + 6 grams. For the 2-week body weight, 9 = 2 0 + 9 grams. And f o r the 3-week body weight, 9 = 2 0 + 1 1 grams. TEST 2: U.B.C. B r o i l e r s The average weekly body weights and t h e i r analyses v a r i a n c e are shown i n Appendix B, Table B3. The average weekly growth r a t e s as w e l l as the average growth r a t e s f o r the 1 to 3-week p e r i o d and the 3 to 7-week p e r i o d and t h e i r analyses of v a r i a n c e are shown i n Appendix B, Table B4. In thesej two t a b l e s , the treatments were as f o l l o w s : F l o o r ( c o n v e n t i o n a l pen b r o o d i n g ) . Chamber 1 (high r a d i a t i o n l e v e l b r o o d i n g ) . Chamber 2 (low r a d i a t i o n l e v e l b r o o d i n g ) . The a n a l y s i s of v a r i a n c e of the average f i r s t week body weights i n d i c a t e d t h a t c h i c k s brooded i n the two chambers were s i g n i f i c a n t l y s u p e r i o r (probability < 0.01) than c h i c k s brooded with the c o n v e n t i o n a l system. T h i s i s i n agreement wit h the r e s u l t s of t e s t 2. But, u n l i k e t e s t 1, there was a h i g h l y s i g n i f i c a n t d i f f e r e n c e (11 grams) i n 1-week body weight between the two l e v e l s of thermal r a d i a t i o n i n favour of the high l e v e l (chamber 1). During the f o l l o w i n g weeks of the t e s t , there was a steady d e c l i n e i n growth r a t e s of b i r d s r e a r e d i n the chambers, as i n d i c a t e d by the average weekly growth r a t e analyses of v a r i a n c e (Table B4). T h i s d e c l i n e i n growth r a t e s , s t a r t i n g d u r i n g the second week of growth, was mainly due to a d i s e a s e (porosis) which was observed, i n the chambers o n l y , e a r l y d u r i n g the second week of growth. Dead and v i s i b l y d i s e a s e d b i r d s were n e g l e c t e d from the r e p o r t e d a n a l y s e s . Using S c h e f f e ' s method, the 95 per c e n t confidence l e v e l l i m i t s f o r the c o n t r a s t between c h i c k s brooded i n the chambers and c h i c k s brooded on the f l o o r , may be c a l c u l a t e d . We have the c o n t r a s t , /N /\ /\ © = + v2 ~ 2v3- For the 1-week body weight, 0 = 7 5 + 1 7 grams. For the 2-week body weight, 0 = 2 8 + 3 4 grams. And f o r t h e 3-week body w e i g h t , 0 = -44 + 53 grams. S i m i l a r l y , t h e 95 p e r c e n t c o n f i d e n c e l e v e l l i m i t s f o r t h e d i f f e r e n c e i n w e e k l y body w e i g h t s , between h i g h l e v e l o f r a d i a t i o n (chamber 1) and f l o o r t r e a t m e n t s may be c o n s t r u c t e d . We have t h e c o n t r a s t , e = u 1 - u 3- F o r t h e 1-week body w e i g h t , 9 = 4 3 + 1 0 grams. F o r t h e 2-week body w e i g h t , 9 = 1 9 + 2 0 grams. And f o r t h e 3-week body w e i g h t , 0 = - 8 + 3 1 grams. TEST 3: U.B.C. B r o i l e r s The a v e r a g e w e e k l y body w e i g h t s w i t h t h e i r a n a l y s e s o f v a r i a n c e a r e shown i n A p p e n d i x B, T a b l e B5. The a v e r a g e w e e k l y g r o w t h r a t e s as w e l l as t h e a v e r a g e 1 t o 3-week p e r i o d and t h e a v e r a g e 3 t o 7-week p e r i o d g r o w t h r a t e s a r e i n c l u d e d i n A p p e n d i x B, T a b l e B6. I n t h e s e t a b l e s t h e t r e a t m e n t s a r e as f o l l o w s : F l o o r ( c o n v e n t i o n a l h e a t lamp b r o o d i n g ) . Chamber 1 (low r a d i a t i o n l e v e l b r o o d i n g ) . Chamber 2 ( h i g h r a d i a t i o n l e v e l b r o o d i n g ) . From t h e w e e k l y body w e i g h t a n a l y s e s o f v a r i a n c e , T a b l e B5, we c a n c o n c l u d e : F i r s t , on the average, week one and week two body weights of the c h i c k s brooded i n the two chambers were s i g n i f i c a n t l y higher ( p r o b a b i l i t y < 0.01) than the c o r r e s - ponding body weights of b i r d s brooded under heat lamps. Second, from week three to week seven, there was no s i g n i f i c a n t d i f f e r e n c e between the average value of weekly body weights of the b i r d s i n the chambers and the f l o o r b i r d s T h i r d , from week two to week f i v e , the weekly body weights f o r b i r d s brooded under high thermal r a d i a t i o n l e v e l (chamber 2) were s i g n i f i c a n t l y h i g h e r ( p r o b a b i l i t y < 0.01) than the weekly body weights f o r b i r d s brooded under low r a d i a t i o n l e v e l (chamber 1). The S c h e f f e ' s l i m i t s a t the 95 percent l e v e l of con f i d e n c e f o r the c o n t r a s t /\ S\ 0 = V ± + y 2 - 2y 3 are, f o r the 1-week body weight, 6 = 1 9 + 1 3 grams. For the 2-week body weight, 0 = 2 6 + 2 4 grams. For the 3-week body weight, 0 = 2 2 + 4 0 grams. For the 4-week body weight, © = - 5 + 5 7 grams. And, f o r the 5-week body weight, 0 = 2 1 + 7 7 grams. 48 . S i m i l a r l y , the'Scheffe 1 s l i m i t s f o r the d i f f e r e n c e i n weekly body weights, between the hig h l e v e l of thermal r a d i a t i o n (chamber 2) and f l o o r treatments, are: 0 = y 2 - y 3 f o r the 1-week body weight, 9 - 8 + 7 grams. For the 2-week body weight, 6 = 2 0 + 1 4 grams. For the 3-week body weight, © - 3 1 + 2 3 grams. For the 4-week body weight, 0 = 2 4 + 3 3 grams. And f o r the 5-week body weight, 0 = 3 8 + 4 5 grams. The analyses of v a r i a n c e of the mean weekly growth r a t e s f o r the f i r s t three week p e r i o d of growth, i n d i c a t e d the same tr e n d as the pr e v i o u s two t e s t s . On the average,- the hatch to 1-week growth r a t e of b i r d s r e a r e d i n the two chambers, was higher compared to the growth r a t e f o r the same p e r i o d of t h e i r contemporaries r e a r e d on the f l o o r . However, the s i t u a t i o n was r e v e r s e d d u r i n g the f o l l o w i n g two weeks of growth (Table B6). I t i s of importance to mention t h a t the same d i s e a s e as i n t e s t 2 was observed again w i t h i n the b i r d s i n the chambers, but to a l e s s e r degree. TEST 4: U.B.C. B r o i l e r s The average weekly body weights and t h e i r analyses of v a r i a n c e are shown i n Appendix B, Table B7. The average weekly growth r a t e s , the 1 to 3-week and the 3 to 7-week growth r a t e s and t h e i r analyses of v a r i a n c e are shown i n Appendix B, Table B8. In these t a b l e s , the two•treatments are as f o l l o w s : F l o o r ( c o n v e n t i o n a l heat lamp b r o o d i n g ) . Chamber 2 (high r a d i a t i o n l e v e l , the same s t a r t i n g b l a c k globe temperature as i n the p r e v i o u s t e s t s , but the f i n a l globe temperature was i n c r e a s e d from 70°F (21°C) to"80°F (26.7°C)). The average weekly growth r a t e analyses of v a r i a n c e show an a l t e r n a t i n g t rend of s i g n i f i c a n c e and n o n - s i g n i f i c a n c e . T h i s t r e n d i s unique to t h i s t e s t , and i t i s probably a r e s u l t of the m o d i f i e d r a t e of b l a c k globe temperature drop. In the p r e v i o u s t e s t s , the average hatch to 1-week growth r a t e of b i r d s brooded i n the chambers was s i g n i f i c a n t l y h i g h e r than t h a t of b i r d s brooded on the f l o o r , w h i l e i n t h i s t e s t the s i t u a t i o n was r e v e r s e d . T h e r e f o r e , m a i n t a i n i n g a b l a c k globe temperature of 88°F (31.1°C), Table 2, f o r the whole f i r s t week of the t e s t had an adverse e f f e c t on growth r a t e of chamber b i r d s . The r e v e r s e s i t u a t i o n o c c u r r e d again d u r i n g the second week of growth. The chamber b i r d s had a s u p e r i o r 1 to 2-week growth r a t e to f l o o r b i r d s , w h i l e i n the p r e v i o u s t e s t s , the o p p o s i t e s i t u a t i o n o c c u r r e d . There- f o r e , d u r i n g the second week of growth, a b l a c k globe 50 . temperature o f 84°F (28.9°C), Table 2, was b e t t e r f o r growth than a b l a c k globe temperature of 82°F (27.8°C) dropping to 76°F (24.4°C) d u r i n g the l a t e r p a r t of the week, Table 1. F i n a l l y , the p r e s e n t t e s t i n d i c a t e d no s i g n i f i c a n t d i f f e r e n c e i n the 2 to 3-week growth r a t e between chamber and f l o o r b i r d s , w h i l e p r e v i o u s t e s t s showed a s u p e r i o r growth r a t e d u r i n g the t h i r d week of growth i n favour of f l o o r b i r d s . T h e r e f o r e , a b l a c k globe temperature of 80°F (26.7°C) d u r i n g the t h i r d week gave s l i g h t l y b e t t e r r e s u l t s than a globe temperature of 73°F (22.8°C) dropping to 70°F (21°C). b) Warm A i r Brooding Experiment: Commercial B r o i l e r s TESTS: 5 and 6 The mean weekly body weight with t h e i r analyses of v a r i a n c e f o r t e s t 5 and f o r t e s t 6, females and males, are i n c l u d e d i n Appendix C, Tables C l , C3, C5 and C7, r e s p e c t i v e l y . The average weekly growth r a t e s as w e l l as the 1 to 3-week growth r a t e s with t h e i r analyses of v a r i a n c e are a l s o i n c l u d e d i n Appendix C, Tables C2, C4, C6 and C8, r e s p e c t i v e l y . The body weight analyses of v a r i a n c e i n d i c a t e d a s i g n i f i c a n t d i f f e r e n c e i n the 1-week body weights i n favour of the b i r d s reared i n the chambers compared to b i r d s r e a r e d on the f l o o r . T h i s d i f f e r e n c e was presen t i n both t e s t s and f o r fc?oth sexes. But, d u r i n g the f o l l o w i n g two weeks, the d i f f e r e n c e i n body weights remained s i g n i f i c a n t f o r females o n l y . I t i s important to note the s i g n i f i c a n t d i f f e r e n c e i n 3-week body weight between the two chambers. T h i s d i f f e r e n c e was i n favour of b i r d s i n chamber 1. I t i s a l s o important to note t h a t the above tr e n d was c o n s i s t e n t l y p r e s e n t i n both t e s t s and f o r both sexes. The analyses of v a r i a n c e t a b l e s f o r growth r a t e s (Appendix C) i n d i c a t e d t h a t the growth r a t e of b i r d s i n chamber 2 s t a r t e d to f a l l behind t h a t o f b i r d s i n chamber 1 d u r i n g the second week of growth. A l s o , these t a b l e s i n d i c a t e d t h a t the d i f f e r e n c e i n growth r a t e s of the two chambers become h i g h l y s i g n i f i c a n t d u r i n g the t h i r d week. During t h i s p e r i o d , the growth r a t e s of the male b i r d s i n t e s t 5 were 3.39 and 3.12 f o r chamber 1 and chamber 2, r e s p e c t i v e l y ; and, i n t e s t 6, they were 3.19 and 2.86 f o r chamber 1 and chamber 2, r e s p e c t i v e l y . The cause of the d i f f e r e n c e i n growth r a t e s c o u l d not be environmental, s i n c e the two chambers were p r a c t i c a l l y a t the same environmental c o n d i t i o n s . The cause of t h i s d i f f e r e n c e was due to the f a c t t h a t the feeder i n chamber 2 was s m a l l e r than the feeder i n chamber 1. O b v i c u s l y , the c a p a c i t y of the feeder d i d not i n f l u e n c e the b i r d s d u r i n g the e a r l y stage of growth but, as the feed con- sumption i n c r e a s e d , the feeder c a p a c i t y became a f a c t o r . 3 . Resui.ts Of the L i n e a r M u l t i p l e Regression Analyses , a) I n f r a r e d brooding experiment The simple and m u l t i p l e c o e f f i c i e n t s of determina- 2 t i o n (R ) f o r the 3-week body weight with 1-week body weight, 1 to 2-week growth r a t e , 2 to 3-week growth r a t e and 1 to 3- week growth r a t e , are shown i n Appendix D (Table D I ) . F o r a l l treatments, the 1-week body weight alone e x p l a i n e d between 70%-85%, 26%-59%, 41%-62% and 47%-54% of the v a r i a b i l i t y i n the 3-week body weight f o r t e s t 1, 2, 3 and 4 r e s p e c t i v e l y . The simple c o r r e l a t i o n c o e f f i c i e n t s between the 3-week body weight and each one of the three growth r a t e s l i s t e d above, were g e n e r a l l y low and n o n - s i g n i f i c a n t . I t i s i n t e r e s t i n g to note t h a t only the f o l l o w i n g two t r a i t s , 1-week body weight and 1 to 3-week growth r a t e , were needed to account f o r almost 100 p e r c e n t of the v a r i a b i l i t y i n the 3-week body weight. The c o e f f i c i e n t s o f d e t e r m i n a t i o n f o r the 7-week body weight with 1-week body weight, 1 to 3-week growth r a t e and 3 to 7-week growth r a t e are i n c l u d e d i n Appendix D (Table D2). I t i s of i n t e r e s t to note t h a t f o r a l l treatments the c o r r e l a t i o n s between the 7-week body weight and 1-week body weight (Table D2) were lower than the c o r r e l a t i o n s between 3-week body weight and 1-week body weight (Table DI). As was expected, the combination of the three t r a i t s , 1-week body weight, 1 to 3-week growth r a t e and 3 to 7-week growth r a t e , e x p l a i n e d most of the v a r i a b i l i t y i n the 7-week body weight, b) Warm A i r Brooding Experiment The c o e f f i c i e n t s of d e t e r m i n a t i o n f o r the 3-week body weight with 1-week body weight, 1 to 2-week growth r a t e , 2 to 3-week growth r a t e and 1 to 3-week growth r a t e are t a b u l a t e d i n Appendix D (Table D3) f o r t e s t 5 and (Table D4) f o r t e s t 6. The r e g r e s s i o n analyses f o r the two t e s t s i n d i c a t e d t h a t the 1-week body weight e x p l a i n e d between 4 4 and 7 6 per- cent (a s i g n i f i c a n t amount) of the v a r i a t i o n a s s o c i a t e d w i t h the 3-week body weight, assuming a l l other independent v a r i a b l e s were kept c o n s t a n t . The other simple c o e f f i c i e n t s of d e t e r m i n a t i o n were g e n e r a l l y low. As i n the i n f r a r e d brooding experiment, the f o l l o w i n g two t r a i t s , 1-week body weight and 1 to 3-week growth r a t e e x p l a i n e d almost a l l the v a r i a b i l i t y i n the 3-week body weight. . I n f r a r e d and Warm A i r Brooding: A Comparison For the purpose of comparison, Table 5 was c o n s t r u c t e d which r e p r e s e n t s a summary of the r e s u l t s f o r the brooding p e r i o d , hatch to three weeks of age. Tes t 1 was n e g l e c t e d , because New Hampshires\ were used as experimental m a t e r i a l i n s t e a d of b r o i l e r s ; t h e r e f o r e , no comparison c o u l d be made between t e s t 1 and other t e s t s o f the experiment. Table 5 shows the average weekly body weights i n grams and t h e i r r e s u l t i n g average weekly growth r a t e s . The a c t u a l treatments w i t h t h e i r i d e n t i f i c a t i o n s are l i s t e d below the t a b l e . As the t a b l e i n d i c a t e s , some of the treatments were r e p l i c a t e d once or more. I t i s of i n t e r e s t to note the growth r a t e t r e n d of each treatment. During a l l the t e s t s , the growth r a t e s of the 54. TABLE 6. Average weekly body weights i n grams and average weekly growth r a t e s as by t r e a t m e n t , f o r t e s t s 2, 3, 4, 5 and 6 ( m a l e s ) . Age (weeks) Growth p e r i o d T e s t No T r e a t - ment H 1 2 3 H - l 1-2 2-3 n 2 E . 43 98 294 543 2.87 4.95 3.37 22 3 E 45 127 283 511 3.65 3 .57 3.25 30 F l o o r 4 E 47 124 278 500 3.34 3.63 3.22 37 5 E 46 115 290 542 3.14 4 .15 3.43 24 6 E 41 116 268 497 3. 60 3 .74 3.40 23 2 A 43 141 313 53 5 4.08 3 .60 2.93 20 3 C 44 138 289 502 3.95 3.33 3 .03 25 Chamber 1 5 D 48 126 301 559 3 .36 3.91 3 .39 14 6 D 42 124 277 496 3.77 3 .60 3.19 18 2 C 42 130 303 507 3.89 3 . 81 2 .82 25 3 A 44 135 303 542 3.88 3 .64 3.18 27 Chamber 2 4 B 47 120 288 519 3 . 28 3.92 3 .22 26 5 D 48 125 297 525 3.34 3.90 3.12 18 6 D 41 125 269 452 3. 89 3.42 2. 86 11 Nomenclature below: A: High r a d i a t i o n l e v e l b r o o d i n g , f i n a l BGT o f 70°F (21.1°C) B: High r a d i a t i o n l e v e l b r o o d i n g , f i n a l BGT of 80°F (26.7°C) C: Low r a d i a t i o n l e v e l b r o o d i n g , f i n a l BGT o f 70°F (21.1°C) D: Warm a i r b r o o d i n g , r e l a t i v e humdity = 50% E: Heat lamps b r o o d i n g . H: Hatch n : Number of birds TABLE 7. Sc h e f f e ' s l i m i t s at the 95% confidence l e v e l f o r the s p e c i f i e d c o n t r a s t s f o r t e s t s 2, 3, 5 and 6 (males). AGE C o n t r a s t * T e s t No. Week 1 Week 2 Week 3 CO < 3 - 1 2 75+17 28+34 -44+53 CN 3 19+13 26+24 22+40 + ,—j 5 21+17 18+37 0+60 < 3 . II 6 17 + 15 10+35 -46+60 CD e = y 3 2 43+10 19+20 - 8+31 e = ^2 " y 3 3 8+ 7 20+14 31+23 e = y l " ^3 5 11+10 11+23 17 + 37 e y i " ^3 6 8+ 8 9 + 19 - 1+33 * M l = estimated mean of chamber 1 b i r d s y = estimated mean of chamber 2 b i r d s y 3 = estimated mean of f l o o r b i r d s f l o o r b i r d s i n d i c a t e d a low-high-low trend. The low hatch to 1-week growth r a t e i n d i c a t e d the b i r d s were s t r e s s e d during t h e i r f i r s t week of growth. This s t r e s s was due to e i t h e r a recovery from hatching e f f e c t and/or an environmental e f f e c t . The same growth r a t e trend occurred during t e s t 4, i n chamber 2, w i t h the high r a d i a t i o n l e v e l and high f i n a l black globe temperature treatment. However, during t e s t s 2 and 3, i n chambers 1 and 2, wit h the high l e v e l of r a d i a t i o n and low f i n a l black globe temperature treatment, the growth r a t e s showed a decreasing trend w i t h age. These growth r a t e trends i n d i c a t e d the importance of the r a t e of change of the black globe temperature w i t h time. Furthermore, a t a b l e of confidence i n t e r v a l s i s included f o r a b e t t e r a p p r e c i a t i o n of the d i f f e r e n c e between some of the treatment means of Table 5. These confidence l i m i t s at the 95 percent l e v e l , f o r some s e l e c t e d c o n t r a s t s , are shown i n Table 6. The l a r g e s t treatment d i f f e r e n c e of 43 + 10 grams occurred during t e s t 2. This d i f f e r e n c e was between the high l e v e l thermal r a d i a t i o n and the f l o o r treatments. 57 . CONCLUSIONS The i n t e n s i t y and u n i f o r m i t y of thermal r a d i a t i o n w i t h i n the c o n t r o l l e d environment chambers were s t u d i e d using the f o l l o w i n g two methods: a) The r a d i o s i t y method. b) The b l a c k globe thermometer method. The i n c i d e n t r a d i a n t energy was determined a t nine d i f f e r e n t l o c a t i o n s w i t h i n the chamber, and i t was found t h a t : a) The v a r i a t i o n s between l o c a t i o n s were s m a l l . b) For a l l l o c a t i o n s , the r a d i o s i t y method p r e d i c t e d about 5 percent higher v a l u e s of i n c i d e n t r a d i a t i o n than val u e s determined by the b l a c k globe thermometer. A f i r s t experiment was designed to study the e f f e c t s of i n f r a r e d energy on p o u l t r y . A t o t a l of 311 young male c h i c k s , 99 New Hampshires, and . 212 U.B.C. b r o i l e r s were used i n the experiment. T h i s experiment c o n s i s t e d o f f o u r t e s t s , with three treatments i n each t e s t ; a high r a d i a t i o n l e v e l , a low r a d i a t i o n l e v e l and a c o n v e n t i o n a l heat lamp brooding system. I t was found t h a t : a) On the average, the weekly body weights, f o r the f i r s t three of growth, of b i r d s brooded under the low and high l e v e l s of r a d i a t i o n were s i g n i f i c a n t l y h i g h e r than the corresponding body weights of b i r d s r e a r e d under heat lamps. b) B i r d s brooded under the high l e v e l of r a d i a t i o n were s u p e r i o r to b i r d s brooded under the low l e v e l of r a d i a t i o n . 58 . A second experiment was designed to compare warm a i r brooding to heat lamp br o o d i n g . A t o t a l of 212 mixed sex commercial b r o i l e r s were used i n the experiment. T h i s e x p e r i - ment c o n s i s t e d of two t e s t s , w i t h the treatments i n each t e s t ; chamber 1, chamber 2 and f l o o r (heat lamp b r o o d i n g ) . The two chambers were maintained a t the same environmental c o n d i t i o n s f o r each t e s t . I t was found t h a t : a) On the average, the weekly body weights of b i r d s with warm a i r were hig h e r than the weekly body weights of b i r d s brooded under heat lamps. b) There was a s i g n i f i c a n t chamber e f f e c t , d u r i n g the t h i r d week of growth, i n favour of chamber 1. When the high l e v e l of thermal r a d i a t i o n of the f i r s t experiment was compared to the warm a i r experiment, the weekly body weights of the former treatment were higher or a t l e a s t equal to the weekly body weights of the l a t t e r treatment. LIST OF REFERENCES ASHVE Research T e c h n i c a l A d v i s o r y Committee on Instruments. "Measurement of p h y s i c a l p r o p e r t i e s of the thermal environment", Heating, P i p i n g and A i r C o n d i t i o n i n g , 14: 382-385, 1942. Baker, V.H. and J.H. Bywaters. ''Brooding P o u l t r y with I n f r a r e d Energy". Agr. Eng. 42: 316^320, June 1951. Baxter, D.O., T.E. Maddox and H.V. S h i r l e y . "Temperature p r e f e r e n c e s of c h i c k s " . T r n a s a c t i o n s of the ASAE, V o l . 13, No. 6, pp. 788^791, 1970. Bedford, T. and C.G. Warner. "The globe thermometer i n s t u d i e s of h e a t i n g and v e n t i l a t i n g " . J o u r n a l of Hygiene, 34: 458, 1934. Bond, T.E. and C E . K e l l y . "The globe thermometer i n a g r i c u l t u r a l r e s e a r c h " . Agr. Eng. 36: 251-255, A p r i l , 1955. Brownlee, K.A. S t a t i s t i c a l Theory and Methodology i n Science and E n g i n e e r i n g . John Wiley & Sons, N.Y. 1960. Bruce, W. Man and His Thermal Environment. T e c h n i c a l Paper No. 84, D i v i s i o n of B u i l d i n g Research, N a t i o n a l Research C o u n c i l of Canada, Ottawa, NRC 5514, pp. 123-126, February 1960. 60. 8. Longhouse, A.D. and H.L. Garver. " P o u l t r y environments". ASHRAE J o u r n a l , 68-74, J u l y 1964. 9. McCluskey, W.H. and G.H. A r s c o t t . "The i n f l u e n c e of incandescent and i n f r a r e d l i g h t upon c h i c k s " . P o u l t r y S c i e n c e , 46: 528-29, 1967. 10. Parker, B.F., E.M. Smith and B.P. Verma. "Black sphere thermal radiometry". T r a n s a c t i o n s of the ASAE 10: 780-783, 1967. 11. P e r e i r a , N., T.E. Bond and S.R. M o r r i s o n . "Thermal c h a r a c t e r i s t i c s of a t a b l e - t e n n i s - b a l l used as a b l a c k - g l o b e thermometer". ASAE paper No.66-328, 1966. 12. Roberts, C.W. " E s t i m a t i o n of e a r l y growth r a t e i n the c h i c k e n " . P o u l t r y S c i e n c e , 43: 238-252, January, 1964. 13. S i e g e l , R. and J.R. Howell. Thermal R a d i a t i o n Heat T r a n s f e r . McGraw-Hill Book Company, N.Y., 1972. 14. Skoglund, W.C. and D.H. Palmer. " L i g h t i n t e n s i t y s t u d i e s w i t h b r o i l e r s " . P o u l t r y S c i e n c e , 41: 1839-1842, 1962. 15. Sparrow, E.M. and R.D. Cess. R a d i a t i o n Heat T r a n s f e r . Brooks/Cole P u b l i s h i n g Company, Belmont, C a l i f o r n i a , 1970. 16. S t a l e y , L.M., C.W. Roberts and D.C. Crober. "The e f f e c t of thermal r a d i a t i o n on e a r l y growth of the New Hampshire c h i c k e n " . Can. Agr. Eng. 9: 39-42, January, 1967. 61. 17. S t a l e y , L.M. and C.W. Roberts. "Design and development of c o n t r o l l e d environment brooders f o r p o u l t r y " . Can. Agr. Eng. 11: 71-73, November 1969. 18. S t a l e y , L.M., C.W. Roberts and S. Paulson. "Improved growth o f p o u l t r y u t i l i z i n g c o n t r o l l e d e n v i r o n - ments". Can. Agr. Eng. 12: 76-79, November 197 0. 62. APPENDIX A TABLE A l AVERAGE SURFACE TEMPERATURE EMITTANCE AND SURFACE AREA OF THE SURFACES OF THE CHAMBER. Surface M a t e r i a l Surface S i z e Emittance Average No. ( i n ) Temperature (°F) 1 white p a i n t UO x 40 ' 0.90 136 2 wood 4 0 x 4 0 0.85 82 3 o x i d i z e d 40 x 13 0.20 74 alum. 4 " 40 x 16 0.20 68 5 " 40 x 13 0.20 82 6 " 40 x 16 0.20 70 7 p l e x i g l a s s 40 x 13 0.90 82 8 o x i d i z e d A l 40 x 16 0,20 70 9 " 40 x 13 0.20 87 10 " 40 x 16 0.20 72 64 . TABLE A2 CONFIGURATION FACTORS BETWEEN THE SURFACES OF THE CHAMBER. 1 F l - i F 2 - i F 3 - i F 4 - i ? 5 - i F 6 - i F 7 - i F 8 - i F 9 - i F 1 0 - i 1 0 0.293 0.329 0.175 0.329 0.175 0.329 0.175 0.329 0.175 2 0.293 0 0.160 0.312 0.160 0.312 0.160 0.312 0.160 0.312 3 0.107 0.052 0 0 0.125 0.048 0.070 0.065 0.125 0.048 4 0.070 0.125 0 0 0.060 0.139 0.080 0.096 0.060 0.139 5 0.107 0.052 0.125 0.049 0 0 0.125 0.048 0.070 0.065 6 0.070 0.125 0.060 0.139 0 0 0.060 0.139 0.080 0.096 7 0.107 0.052 0.070 0.065 0.125 0.049 0 0 0.125 0.048 8 0.070.0.125 0.080 0.096 0.060 0.139 0 0 0.060 0.139 9 0.107 0.052 0.125 0.049 0.070 0.065 0.125 0.049 0 0 10 0.070 0.125 0.060 0.139 0.080 0.096 0.060 0.139 0 0 T o t a l 1.001 1.001 1.009 1.025 1.009 1.023 1.009 1.023 1.009 1.022 TABLE A3 THE - MATRIX OF COEFFICIENTS AND THE COLUMN VECTOR OF CONSTANTS FOR THE • SOLUTION OF THE SYSTEM OF LINEAR NONHOMOGENEOUS EQUATIONS ON DIGITAL COMPUTERS + 1.0 -0. 0293 -0. 0107 -0. 0070 -0. 0107 -0. 0070 -0. 0107 -0 .0070 -0. 0107 -0. 0070 V 194. 64 -0. 04 3 9 + 1. 0 -0. 0078 -0. 0187 -0. 0078 -0. 0187 -0. 0078 -0 . 0187 -0. 0078 -0. 0187 ! B2 125 . 73 -0. 26 32 -0. 1280 + 1. 0 0. 0 -0. 1000 -0. 0480 -0. 0560 --0 .0640 -0. 1000 -0. 0480 ! B3 27. 87 -0. 1400 -0. 2497 0. 0 + 1. 0 -0 . 0392 -0. 1112 -0. 0 5 20 -0 . 0768 -0, 0392 -0. 1112 V 26. 64 -0. 2632 -0. 1280 -0. 1000 -0. 0480 + 1. 0 0. 0 -0. 1000 -0 . 0480 -0. 0560 -0. 0640 B,- I 5 i 29. 58 -0 . 1400 -0. 2496 -0. 0384 -0. 1112 0 . 0 + 1. 0 -0 . 0392 -0 .1112 -0 . 0520 -0. 0768 ! B6 - 27. 05 -0. 0329 -0. 0160 -0. 0070 -0 . 0080 -0 . 0125 -0. 0060 + 1. 0 0 . 0 -0. 0125 -0 . 0060 h 133. 12 -0. 1400 -0 . 2496 -0. 052 -0. 0768 -0 . 0384 -0. 1112 0. 0 + 1 . 0 -0. 0392 -0. 1112 B8 27. 05 -0. 2632 -0. 128 -0, 1000 -0 . 0480 -0. 0560 -0. 0640 -0. 1000 -0 . 0480 +1. 0 0 . 0 B 9 30. 59 -0. 140 0 2496 -0. 0 3 84 -0. 1112 -0. 0520 -0. 0 7 68 -0. 0384 -0 .1112 0. 0 +1. 0 ! J i B i o | 27. 46 66 . TABLE A4 CONFIGURATION FACTOR BETWEEN THE SPHERE AT DIFFERENT LOCATIONS AND THE WALLS OF THE CHAMBER. LOCATION OF GLOBE IN CHAMBER Surface —• —•—• A l A2 A3 BI B2 B3 C l C2 C3 1 0.162 0.203 0.162 0.203 0.248 0.203 0.162 0.203 0.162 2 0.138 0.168 0.138 0 . 168 0.208 0.16.8 0.138 0.168 0.138 3 0.025 0.029 0.025 0.051 0.063 0.051 0.144 0.168 0.144 4 0.030 0.035 0.030 0.059 0.073 0.059 0.151 0.177 0.151 5 0.144 0.051 0.025 0.168 0.063 0.029 0.144 0.051 0.025 6 0.151 0.059 0.030 0.177 0.073 0.035 0.151 0.059 0.030 7 0.144 0.168 0.144 0.051 0.063 0.051 0.025 0.029 0.025 8 0,151 0.177 0.151 0.059 0.073 0.059 0.030 0.035 0.030 9 0.025 0.051 0.144 0.029 0.063 0.168 0.025 0.051 0.144 10 0.030 0.059 0.151 0.035 0.073 0.177 0.030 0.059 0.151 10 E F . 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000 1.000 i = l g TABLE A5 INCIDENT RATIATION*ON THE GLOBE FOR THE 9 LOCATIONS Surface LOCATION OF GLOBE ON THE CHAMBER N o - Al A2 A3 BI B2 B3 Cl C2 C3 1 34.18 42.82 34.18 42.82 52.32 42.82 34.18 42.82 34.18 2 21.08 25.65 21.08 25.65 31.75 25.65 21.08 25.65 21.08 3 ~~ 4. 32 5.01 4.32 8,81 10.89 8 . 81 24.89 29 . 04 24.89 4 4.97 5.80 4.97 9.77 12.09 9.77 25.00 29.31 25.00 5 24.96 8.85 4.34 29.14 10.93 5.03 24.96 8.85 4.34 6 25.08 9.80 4.98 29.39 12.12 5.81 25.08 9.80 4.98 7 21.80 25.43 21.80 7.72 9.54 7.72 3.78 4.39 3.78 8 25.19 29.53 25.19 9.84 12.18 9.84 5.00 5.84 5.00 9 4.36 8.90 25,12 5.06 11.00 29.31 4.36 8.90 25.12 10 4.99 9.81 25.11 5.82 12.14 29.43 4.99 9.81 25,11 Total 170.93 171-60 171.09 174.02 174.96 174.19 173.32 174.41 173.48 * U n i t s : BTU h r - 1 f t - 2 TABLE A6 AIR VELOCITY, AIR TEMPERATURE, GLOBE TEMPERATURE AND RESULTING MEAN RADIANT TEMPERATURE OF THE GLOBE FOR THE 9 LOCATIONS (heat panel temperature = 136°F = 58°C) LOCATION OF GLOBE IN THE CHAMBER A l A 2 A3 BT B2 B3 C l C2 C3 Mean A i r v e l o c i t y (FPM) 7.0 3.2 4.3 7.0 3.6 7.6 20 .0 24 .7 14 .8 10.2 A i r temperature (°F) 74.0 74.0 75.0 69.5 78.0 74 .0 65.5 68.0 73.0 72.3 Globe tempera- t u r e (°F) 80.2 80.6 83.1 78.0 82.4 82.4 73.6 74 .0 79 .3 79.3 MRT (°F) 83.5 82.9 86.3 82.5 85.1 86.8 80 .8 79.8 84 .0 83.5 RHL (BTU h r " 1 f t - 2 ) 150.9 150.3 153.1 149.9 152.7 154.7 147.9 146.9 151.6 150.9 RHL ( c o r r e c t e d to the standard • ^ r K 6 i n b l a c k globe) 163.8 161.8 166.2 162.7 163.3 167.9 163.6 163.3 166.3 164.3 69 . APPENDIX B , j TABLE BI a) Average weekly body weights 3* of t e s t 1 as by treatment. Treatment A G E (n) Hatch Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 F l o o r (33) 42 74 148 256 386 535 719 923 Chamber 1 (33) 41 89 164 271 391 539 720 926 Chamber 2 (33) 42 89 168 276 399 554 740 951 Mean (99) 42 84 160 268 392 543 726 933 b) Weekly body weight analyses of v a r i a n c e i n percentage of t o t a l sums of squares of t e s t 1 f o r treatment e f f e c t . A G E s . v . d.f. Hatch Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Treatments 2 1.2 37 . 3 * * 16 .2** 7 . 3 * * 1.3 1.6 1.6 1.9 -Chambers vs f l o o r 1 - 37 . 3 * * 15.7** 6.9** 0.9 0.7 0.4 0 . 6 -Chamber 1 vs Chamber 2 1 - 0.0 0 .5 0.4 0.4 0.9 1.2 1.3 E r r o r 96 98.8 62.7 83.8 92.7 98 .7 98.4 98.4 9 8 . 1 T o t a l 98 1,031 13,756 47,548 101,729 210,241 376,566 555,727 771,999 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) a i n grams TABLE B2 a) Average growth r a t e s of t e s t 1 as by treatment. Growth P e r i o d Treatment ( (n) H-l 1-2 2-3 3-4 4 -5 5-6 6-7 1-3 3--7 F l o o r Chamber 1 Chamber 2 (33) (33) (33) 1.95 2.64 2.60 3.13 2.74 2. 84 3 . 0 1 2.67 2.46 2.76 2.39 2 .41 2.73 2.38 2.45 2.51 2.47 2.47 2.38 2.39 2.39 3.08 2.75 2.79 2 2 2 .52 .41 .42 Mean 99 2.40 2.90 2.83 2.48 2.44 2.48 2.39 2.87 2 .45 b) Growth of t e s t r a t e analyses of 1 f o r treatment v a r i a n c e i n percentage of e f f e c t . t o t a l sums of squares Growth P e r i o d s . v . d . f . H--1 1--2 2 - : I 3-4 4--5 5--6 6--7 1--3 3- -7 Treatments 2 37. .4** 32, . 21** 25. .6** 34 , .0** 2 , .21 0, .8 0, .1 49 , .7** 14 , 7** -Chambers vs .6** f l o o r 1 37 . 3** 30. .3** 25. .3** 34 , .0** 0, .7 0, .8 . 0, .1 49 , .0** 14 , -Chamber 1 vs Chamber 2 1 0. .1 1. .9 0. .3 0, .0 1, .5 0 , .0 0, .0 0, .7 0 , . 1 E r r o r 96 62, .6 67. .8 74, .4 66 , .0 97 , .8 99 , .2 99 , .9 50 , .3 85 , .3 T o t a l 98 26 , .92 8. .50 6 , .19 5, . 26 2, .08 4 , .31 3, .43 4 , .28 1. .52 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) TABLE B3 a) Average weekly body weights 3 of t e s t 2 as by treatment, Treatment (n) A G E Hatch Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 F l o o r (22) 43 98 294 543 812 1108 1469 1826 Chamber 1 (20) 43 141 313 535 800 1117 1458 1814 Chamber 2 (25) 42 130 303 507 771 1083 1428 1795 Mean (67) 43 123 303 528 794 1103 1452 1812 b) Weekly body weight analyses of v a r i a n c e i n percentage of t o t a l sums of squares of t e s t 2 f o r treatment. A G E S.V. d.f. Hatch Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Treatments 2 2.5 67.4** 7.7 13.4* 7.4 2.8 2.6 0 .8 -Chambers vs f l o o r 1 63.1** 5.3 6.5* 4.2 0.3 1.4 0.5 -Chamber 1 vs Chamber 2 4.3** 2.4 6.8* 3.2 2.5 1.2 0.3 E r r o r 64 97.5 32.6 9 2.3 86.6 92.6 97.2 97 .4 99.2 T o t a l 66 514 32,075 49 ,291 123,264 284,484 492,960 852,416 1, 423,984 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) a i n grams TABLE B4 a) Average growth r a t e s of t e s t 2 as by treatment. Growth P e r i o d Treatment (n) H-1 1-2 2-3 3-4 4-5 5-6 6-7 1-3 3-7 F l o o r Chamber 1 Chamber 2 (22) (20) (25) 2. 87 4.08 3 . 89 4.95 3.60 3.81 3.37 2.93 2 . 82 2.62 2. 61 2.72 2 .33 2.50 2.55 2.40 2.26 2.34 2.06 2.06 2.17 4 . 24 3.30 3.36 2.38 2.39 2.48 Mean (67) 3.61 4.12 3.04 2.65 2.46 2.33 2.10 3.63 2.42 b) Growth r a t e a n a l y ses of v a r i a n c e i n percentage of t o t a l sums of squares - of t e s t 2 f o r treatment e f f e c t . Growth P e r i o d s . v . d.f. H--1 1--2 2--3 3--4 4--5 5--6 6--7 1--3 3--7 Treatments 2 67 . 2 * * 67. .3** 51. . 0** 7. .9 23 . 0** 11. .1* 5 . 7 81. . 8** 15, .8** -Chambers vs f l o o r 1 65. .8** 65. .8** 49 . 4** 1. . 9 21. . 9** 7 . 0* 1. .6 81. .6** 5. . 8* -Chamber 1 vs Chamber 2 1 1. .4 1. . 5 1. . 6 6. .0* 1. .1 4 . 1 4 . 1 0 . 2 10. . 0** E r r o r 64 32 . , 8 32. .7 49 , .0 92. .1 77. .0 88 . 9 94 , .3 18. . 2 84 . 2 T o t a l 66 27 . 64 33. .98 7. . 59 2. . 26 2, .75 2. .06 3 , .45 14 . 62 0 . 89 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) TABLE B5 a) A v e r a g e w e e k l y body w e i g h t s 3 , o f t e s t 3 as by t r e a t m e n t . A G E Treatment (n) Hatch Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 F l o o r (30) 45 127 283 511 776 10 8 6 1435 1792 Chamber 1 (25) 44 138 289 502 747 1069 1420 1781 Chamber 2 (27) 44 135 303 542 800 1124 1466 1815 Mean (82). 44 133 292 518 774 1093 1440 1796 b) Weekly body weight analyses of v a r i a n c e i n percentage of t o t a l sums of squares of t e s t 3 f o r treatment e f f e c t . A G E S.V. d . f . Hatch Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Treatments 2 0. .5 13 .3** 15. .2** 18 . ,8** 15. .4** 10 . 4* 4 . 3 1. .5 -Chambers vs f l o o r 1 12 .6** 9. . 0** 2. .2 0 . 0 0. .6 0. .3 0. .1 -Chamber 1 vs Chamber 2 1 0 .7 6. .2* 16. .6** 15. .4** 9 . 8** 4. .0 1. .4 E r r o r 79 99 . 5 86 .7 84. ,8 81. .2 84. .6 89 . 6 95. .7 98 . 5 T o t a l 81 784 11,612 42,029 121,692 231,120 402,368 285,216 1,050,640 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) a i n grams TABLE B6 a) Average growth r a t e s of t e s t 3 as by treatment. Growth P e r i o d Treatment (n) H-l 1-2 2-3 3-4 4-5 5-6 6-7 1-3 3-7 F l o o r Chamber 1 Chamber 2 (30) (25) (27) 3.65 3.95 3 . 88 3.57 3.33 3.64 3.25 3.03 3 .18 2.72 2.58 2.53 2.52 2.68 2.55 2 . 36 2.41 2 . 26 2.11 2.15 2.03 3.43 3 .20 3.43 2.46 2.48 2.37 Mean (82) 3.83 3.51 3.15 2.61 2.58 2.34 2.10 3.35 2 . 44 b) Growth r a t e analyses of v a r i a n c e i n percentage of t o t a l sums of squares of t e s t 3 f o r treatment e f f e c t . Growth P e r i o d S.V. d . f . H-l 1-2 2-3 3-4 4-5 5-6 6-7 1-3 3-7 Treatments 2 15.4** 29.1** 29.4** 16.4** 18.3** 13.3** 7~77* 33.6** 16.4** -Chambers vs f l o o r 1 14.7** 2.2 21.9** 15.7** 7.9** 0.7 0.5 7.8** 2.4 -Chamber 1 vs Chamber 2 1 0.7 26.9** 7.5** 0.7 10.4** 12.6** 7.2* 25.8** 14.0** E r r o r 79 84 . 6 70 . 9 70 . 6 83 . 6 81.7 86 . 7 92.3 66 .4 83 .6 T o t a l (81) 9.34 4.09 3.88 3.26 2.13 2.56 2.70 2.81 1.08 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) TABLE B 7 a) Average weekly body weights 3 of t e s t 4 as by treatment. A G E Treatment (n) Hatch Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 F l o o r Chamber 2 (37) (26) 47 124 47 120 278 288 500 519 765 775 1082 1087 1438 1411 1799 1770 Mean (63) 47 122 283 510 770 1085 1425 1785 b) Weekly body weight analyses of t e s t 4 f o r treatment. of v a r i a n c e i n percentage of t o t a l sums of squares A G E S.V. d. f . Hatch Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Chamber 2 vs f l o o r 1 0.6 2.0 4.7 4.9 0.6 0.1 1.5 1.1 E r r o r 61 99.4 98.0 95.3 95.1 99.4 99.9 98.5 98.9 T o t a l 62 762 8,261 36 ,109 114,451 252,304 446,016 744,592 1,190,896 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) a i n grams TABLE B8 a) Average growth r a t e s of t e s t 4 as by treatment v Growth P e r i o d Treatment (n) H-1 1-2 2-3 3-4 4-5 5-6 6-7 1-3 3 -7 F l o o r Chamber 2 (37) (26) 3.34 3.28 3.63 3.92 3 . 22 3. 22 2.76 2.59 2.61 2.53 2.42 2.13 2.22 2.15 3 .44 3 .61 2 2 .51 .40 Mean (63) 3.31 3.78 3. 22 2.69 2.56 2.32 2.14 3.53 2 .46 b) Growth of t e s t r a t e analyses of 4 f o r treatment v a r i a n c e i n ] e f f e c t . percentage of t o t a l sums of squares Growth P e r i o d S .V. d.f. H-1 1-2 2-3 3-4 4-5 5-6 6-7 1-3 3' -7 -Chamber 2 f l o o r vs 1 1.0 30.8** 0.0 18.3** 1.8 29.9** 0.3 16 .8** 17 . 2** E r r o r 61 99.0 69 .2 100 . 0 81.7 98.2 70.1 99.7 83.2 82 .8 T o t a l 62 7.12 4 . 20 2.16 2.00 3.05 2.08 3.12 2.31 0 .96 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) 78. APPENDIX C \ 79 . TABLE C l a) Average weekly body weights i n grams of t e s t 5 (males)' by treatment Weeks of Age Treatment (n) Hatch 1 2 3 F l o o r (24) 46 115 290 542 Chamber 1 (14) 48 126 301 559 Chamber 2 (18) 48 125 297 525 Mean (56) 47 122 296 542 b) Weekly body weight analyses of v a r i a n c e i n percentage sums of squares of t e s t 5 (males) f o r treatment e f f e c t . Weeks of Age S .V. d. f . 1 2 3 Treatments 2 16.3** 3.1 8.4 - Chambers vs f l o o r 1 16.3** 2.8 0.0 - Chamber 1 vs Chamber 2 1 0.0 0.3 8.4* E r r o r 53 83.7 96.9 91.6 T o t a l 55 9,595 39,659 110,637 ** H i g h l y ' s i g n i f i c a n t (P < 0.01) * s i g n i f i c a n t .' (P < 0.05) 80 . TABLE C 2 a) Average growth r a t e s of t e s t 5 (males) by treatment- Growth P e r i o d Treatment (n) H - l 1-2 2^3 1-3 F l o o r (24) 3.14 4.15 3.43 3.83 Chamber 1 (14) 3.36 3.91 3.39 3.68 Chamber 2 (18) 3.34 3.90 3.12 3.55 Mean (56) 3.28 3.99 3.31 3.69 b) Growth r a t e analyses of v a r i a n c e i n percentage sums of squares of t e s t 5 (males) f o r treatment e f f e c t . Growth P e r i o d S.V. d . f . H - l 1-2 2-3 1-3 Treatments 2 10.4 18.7*'* 33.5** 34.8** - Chambers vs f l o o r 1 10.4* 18.7** 15.8** 29.3** - Chamber 1 vs Chamber 2 1 0.0 0.0 17 .7** 5.5* E r r o r 53 . 89.6 . 81.3 66.5 65.2 T o t a l 55 5 .661 4 .415 3 -224 2 -343 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t •' (P < 0.05) 81. TABLE C3 a) Average weekly body weights i n grams of t e s t 5 (females). by treatment. Weeks of Age Treatment (n) Hatch 1 2 3 F l o o r (16) 47 109 265 469 Chamber 1 (25) 47 125 285 505 Chamber 2 (20) 46 120 276 480 Mean (61) 47 118 275 485 b) Weekly body weight analyses of v a r i a n c e i n percentage sums of squares of t e s t 5 (females) f o r treatment effect.. Weeks of Age S.V. d.f 1 2 3 Treatments 2 22.1** 9.4 12.4* - Chambers vs f l o o r 1 19 .5** 7 .4* 6.1 - Chamber 1 vs Chamber 2 1 2.6 2.0 6.3* E r r o r 58 77.9 90.6 87.6 T o t a l 60 10,557 42,084 117,353 ** h i g h l y s i g n i f i c a n t ; (P < 0.01) * s i g n i f i c a n t (P < 0.05) 82. TABLE C4 a) Average growth r a t e s of t e s t 5 (females) by treatment. Growth P e r i o d Treatment (n) H - l 1 - 2 2 - 3 . 1 - 3 F l o o r (16) 2.93 3.95 3.15 3.59 Chamber 1 (25) 3.40 3.70 3.15 3.45 Chamber 2 (20) 3.34 3.75 3.04 3.43 Mean (61) 3.22 3.80 3.11 3.49 b) Growth r a t e analyses of v a r i a n c e i n percentage sums of squares of t e s t 5 (females) f o r treatment e f f e c t . Growth P e r i o d S.V. d . f . H - 1 1 - 2 2 - 3 1 - 3 Treatments 2 23. 2** 19. 3** 10. 6* 16. -j * * - Chambers vs f l o o r 1 22. g * * 18. 5* * 1. 8 16. 2** - Chamber 1 vs Chamber 2 1 0. 4 0. 8 8. 8* 0. 5 E r r o r 58 76. 8 80. 7 89. 4 83. 3 T o t a l 60 10.358 3.322 1.705 1.657 h i g h l y s i g n i f i c a n t (P < 0.01) s i g n i f i c a n t ! (P < 0.05) 83 . TABLE C5 a) Average weekly body weights i n grams of t e s t 6 (males), by treatment Weeks of Age Treatment (n) Hatch 1 2 3 F l o o r (23) 41 116 268 497 Chamber 1 (18) 42 124 277 496 Chamber 2 (11) 41 125 269 452 Mean (52) 41 122 271 482 b) Weekly body weight analyses of v a r i a n c e i n percentage sums of squares of t e s t 6 (males) f o r treatment e f f e c t . Weeks of Age S .V. d.f. 1 2 3 Treatments 2 13. 8* 2.9 17 . 2* - Chambers vs f l o o r 1 13.7** 1.5 4.3 - Chamber 1 vs Chamber 2 1 0.1 1.4 12.9** E r r o r 49 86 . 2 97.1 82 . 8 T o t a l • 51 6,101 " ' 30,384 102 ,778 , j ** h i g h l y s i g n i f i c a n t (P < 0 .01) * s i g n i f i c a n t (P < 0 .05) TABLE C6 a) Average growth r a t e s of t e s t 6 (males) by treatment • Growth P e r i o d Treatment (n) H>1 1^2 ~2^3 1-3 F l o o r (23) 3.60 3.74 3.40 3.58 Chamber 1 (18) 3.77 3.60 3.19 3.42 Chamber 2 (11) 3.89 3.42 2.86 3.17 Mean (52) 3.75 3.59 3.15 3.39 b) Growth r a t e analyses of v a r i a n c e i n percentage sums of squares of t e s t 6 (males) f o r treatment effect.. Growth P e r i o d S .V. d. f . H -1 1-2 2 -3 1 -3 Treatments 2 14 .7* 19 . 8** 50 .6** 59 . 5** - Chambers vs f l o o r 1 12 .5** 11. 8** 32 .6** 40 .1** - Chamber 1 vs Chamber 2 1 2 .2 8. 0* 18 . 0** 19 .4** E r r o r 49 8 5 .3 80 . 2 49 .4 40 . 5 T o t a l 51 5-000 2.802 4.329 2.238 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) 85. TABLE C7 a) Average weekly body weights i n grams a t t e s t 6 (females)* by treatment Weeks of Age Treatment (n) Hatch 1 2 3 F l o o r (10) 40 103 229 405 Chamber 1 (13) 41 114 251 446 Chamber 2 (20) 40 120 256 433 Mean (43) 40 112 245 428 b) Weekly body weight analyses of v a r i a n c e i n percentage sums of squares of t e s t 6 (females) f o r treatment e f f e c t . Weeks of Age S .V. d . f . 1 2 3 Treatments 2 37 .6** 20 .4* 13.7 - Chambers vs f l o o r 1 31.7** 19.5** 12.0* - Chamber 1 vs Chamber 2 1 5.9 0.9 1.7 E r r o r 40 62.4 79.6 86.3 Total- 42 5,470 23 ,492 73,524 ** ' H i g h l y s i g n i f i c a n t (P < 0.01) S i g n i f i c a n t (P < 0.05) 86 . TABLE C8 a) Average growth r a t e s o f t e s t 6 (females) by treatment . Growth P e r i o d Treatment (n) H - l 1-2 2-3 1-3 F l o o r (10) 3.32 3.58 3.11 3.37 Chamber 1 (13) 3.56 3.53 3.16 3.37 Chamber 2 (20) 3.84 3.38 2.88 3.15 Mean (43) 2.57 2.50 3.05 3.30 b) Growth r a t e analyses of v a r i a n c e i n percentage sums of squares of t e s t 6 (females) f o r treatment e f f e c t . Growth P e r i o d S .V. d . f . H--1 1--2 2--3 1--3 Treatments 2 41, .4** 15, .8* 39 , > 7** 35. .8** - Chambers vs f l o o r 1 27 , 7 , .3 a 5, .5 a 10. .0* - Chamber 1 vs Chamber 2 1 13, .5** 8, .5 a 34 , . 2** 25. . 8** E r r o r 40 58, .6 84, .2 60. .3 64 , .2 T o t a l 42 4-738 2-239 1.864 1.375 ** H i g h l y s i g n i f i c a n t (P < 0.01) * S i g n i f i c a n t (P < 0.05) a Approaching s i g n i f i c a n c e 87 . APPENDIX D ... v ' J • • TABLE DI M u l t i p l e l i n e a r r e g r e s s i o n analyses f o r t e s t s 1 to 4, with 3-week body weight as dependent v a r i a b l e . Dependent v a r i a b l e s R2 f o r t e s t Treatment X l x 2 X 3 X4 1 2 3 4 F l o o r * 70.7 25.9 61.6 47.4 * 1.0 19 .9 2.8 3.3 * 1.0 32.0 0.3 8.4 * 0.0 6.7 1.9 7.6 * * 88.4 89.3 83.0 83.7 * * 88.9 46.9 81.5 83.6 * * 99 .5 99.2 99.8 99.8 * * * 99 .5 99.4 99.8 99.8 Chamber 1 * 85.6 30.6 42.9 * 48 .7 0.8 9.5 * 4.0 15.8 0 . 0 * 25.7 1.5 5.4 * * 93.7 59 .6 77 .1 * * 88 .7 49.0 61.1 * * 99.5 99.3 99.6 * * * 99 .7 99 .3 99.6 Chamber 2 * 70 .0 58.5 40.8 53.9 * 20 .4 0.0 0.0 2.0 * 1.4 15 .0 5.8 0.0 * 19 .3 6.3 1.0 1.1 * * 92.3 87 .3 81.9 90.7 * * 70.1 58 .5 77 .0 77.2 * * 99.8 99.8 99.4 98.4 * * * 99 .8 99.8 99.4 98.5 X-̂  = 1-week body weight. X 2 = 1-2 week growth r a t e . X^ =1 2-3 week growth r a t e . X. '=: 1-3 week growth r a t e . 89 . TABLE D2 M u l t i p l e l i n e a r r e g r e s s i o n analyses f o r t e s t s 1 to 4, with 7-week body weight as dependent v a r i a b l e . Dependent v a r i a b l e s R f o r t e s t Treatment X l x 2 X 3 1 2 3 4 F l o o r * 19.2 17 .2 16.2 28 .4 * 11.4 8.4 4.9 9.9 * 0.6 0.3 10 .4 2.0 * * 66.6 82.7 40 .4 74.5 * * 54.9 20 .1 53.5 41.6 * * * 98.3 99.4 99.7 99.5 Chamber 1 * 71.1 14 .0 25.3 * 24 .9 1.5 1.5 * 11.2 54.3 22.6 * * 85.3 52.6 51.6 * * 79.5 69 .9 54 .4 * * * 99.3 99 .5 99.6 Chamber 2 * 63 .0 38.3 4.8 7.4 * 11.2 0.9 7.7 12.0 * 0.0 5.6 6.0 8.4 * * 82.0 54.4 41.0 47.1 * * 68.4 57.4 24 .7 42.8 * * * 99 .5 99 .7 98.9 97 .4 = 1-week body weight. = 1-3 week growth r a t e . = 3-7 week growth r a t e . TABLE D3 M u l t i p l e r e g r e s s i o n analyses f o r t e s t 5, with 3 -week body weight as dependent v a r i a b l e . Treatment X l X 2 X 3 X4 R 2 R 2 (males) (females F l o o r * 54.8 70.6 * 26.0 21. 2 * 10 . 2 1.7 * 4.4 12.3 * * 92.3 93.4 * * 67.6 76.6 * * * 99.8 99.7 * * 99.8 99.7 Chamber 1 * 43.6 60.8 * 2.9 0.4 * 14 .4 0.5 * 11. 6 0 . 6 * * 79 .1 84.8 * * 63.4 75.5 * * * 99 . 8 99.6 * * 99.7 99.6 Chamber 2 * 74.0 62.4 * 12.3 1.0 * 2.6 1.0 * 16.0 1.0 * * 81.7 91.6 * * 77 . 2 83.4 * * * 99 . 2 99 . 5 * * 9 8.3 99.5 X^ = l^week body^ weight. X^ = 1-̂ 2 week growth r a t e . X = 2-3 week growth, r a t e . X^ = 1-̂ 3 week growth/rate. TABLE D4 M u l t i p l e r e g r e s s i o n analyses f o r t e s t 6, with 3-week body weight as dependent v a r i a b l e . Treatment X l X 2 X 3 X4 R 2 (males) R 2 (females) F l o o r * * * * 65.0 1.3 4.5 12.3 75.5 55.0 6.6 52.7 * * 69 .5 94.5 * * 82.4 86 .6 * * * 84.6 99 .9 * * 99.7 99 .9 Chamber 1 * * * * 58.5 3.1 8.0 8.5 55.2 5.4 6.4 1.0 * * 81.7 90.2 * * 80 . 2 56.8 * * * 99 .7 99 .7 * * 99.7 99.6 Chamber 2 * * * * 68.4 22.9 5.8 9.6 52.3 14.6 27.9 33.8 * * 86 .4 87.8 * * 71.1 77.2 1 * * * 99.8 99 .6 * * 99.7 99.6 X = 1-week body weight. Xy = 1-2 week growth r a t e . X.-, = 2-3 week growth r a t e . X. = 1-3 week growth r a t e .

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