UBC Theses and Dissertations
Preliminary studies on growth, nutrition and blood chemistry of beavers Stephenson, Arthur Bruce
This study was initiated to establish some basic factors concerning beavers which would aid in understanding changes in population numbers. It was desired to obtain optimal and maximal growth rates, to determine the caloric requirements necessary for maintenance, growth and reproduction, to establish "normal" values for various blood constituents and to correlate variations in these constituents with growth and nutrition. In order to maintain beavers in captivity specially designed pens were constructed and a ration formulated and fed to the animals in a pelleted form. Growth rates were established from the weight increases of several yearling beavers and these were compared with data presented in the literature. Only one rate was established for a kit owing to the difficulty in obtaining young beavers, however, this was supplemented with published data. Body weights were regressed against several body measurements and organ weights were regressed against body weights in order to establish the relative rates of gain for different body components. The caloric requirements necessary for maintenance were established for several beavers of different body weights and these were correlated with the quantity of natural beaver foods required for maintenance and growth. The digestibility and time of food passage was also determined for the pelleted ration. "Normal" values for 25 different blood constituents and tests were determined on an age and seasonal basis. These values were discussed in terms of growth, nutrition, stress and disease and compared with published data obtained for other species . These studies indicated that the beaver has a relatively-fast growth rate and has the ability to efficiently utilize foods high in fiber content. It showed a close similarity to other herbivores, especially those with large caecums, the site of extensive cellulose degradation. Minor physiological adaptations to its semi-aquatic type of life were also indicated.
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