UBC Theses and Dissertations
The relationship of cleft palate to riboflavin deficiency and genotype in chickens Juriloff, Diana Marie
The incidence of cleft palate was observed in 1361 F₁, 1531 F₂, and 2275 backcross embryos and chicks from a reciprocal cross between an inbred Leghorn line selected for high incidence (30 to 50%) of cleft palate and a non-cleft palate (New Hampshire; zero %) line. Cleft palate appeared in the F₁ at frequencies less than 1%, in the F₂ at approximately 1%, and in the backcrosses at approximately 8%. When dams were fed a diet deficient in riboflavin, the incidence of cleft palate was shown to increase for the F₂ and backcross progeny to 4% and 12% respectively. The response of cleft palate incidence to riboflavin deficiency was shown to be in large part a genetic characteristic of the embryo itself and not the dam. The reduced hatchability of eggs during maternal riboflavin deficiency was shown to be similar to earlier reports. No evidence of any unusual response of cleft palate line hens to riboflavin deficiency was found for hatchability, chick body weight, nor maternal effect on cleft palate. The cleft palate condition was shown to be semi-lethal, the lethality being partially due to severe expression of the trait. Genetic models were considered and it was suggested that the model to be further tested should be that of 3 recessive loci, one of which involves a fault in the normal metabolism of riboflavin, and a few additive loci controlling penetrance and expressivity of the trait.
Item Citations and Data