Influence of amylase genotypes on growth rate and feed conversion of chickens.

Chickens from two breeds were screened for amylase alleles designated as AmyF and AmyS to establish breeder flocks homozygous for each. Offspring from these flocks were then used to test the hypothesis that AmyF and AmyS amylases differ in their ability to digest cornstarch 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 more related to specific activity of the amylases than to starch source in the diet. The results indicate that in some breeds of chickens selection for AmyS may improve growth and feed efficiency performance.