INFLUENCE OF AMYLASE GENOTYPES ON GROWTH-RATE AND FEED CONVERSION OF CHICKENS

Chickens from two breeds were screened for amylase alleles designated as Amy(F) and Amy(S) to establish breeder flocks homozygous for each. Offspring from these flocks were then used to test the hypothesis that Amy(F) and Amy(S) amylases differ in their ability to digest cornstar ch and wheat starch. The amylase allozymes were found to affect growth and feed conversion performance of the chickens, and the effects were more pronounced in one breed. However, these effects seemed to be mor e related to specific activity of the amylases than to starch source i n the diet. The results indicate that in some breeds of chickens selec tion for Amy(S) may improve growth and feed efficiency performance.