Water and Feed Intake, Feed Efficiency, and Abdominal Fat Levels of Dwarf and Normal Chickens Selected Under Different Water:Feed Ratio Environments

Abstract

Early feed and water intake, feed efficiency, and abdominal fat weights were investigated in normal and dwarf genotypes previously selected for high 8-wk body weight under .4 and 1.6% dietary salt environments. Progeny from the selected lines were evaluated on a normal .4% salt diet in two experiments following Generations 3 and 4. Progeny of lines selected on the .4% salt environment tended to have higher body weights and feed intake than progeny of lines selected on the 1.6% salt environment. There was evidence that progeny from normal birds previously selected on the 1.6% salt environment had higher initial (0 to 6 days) water:feed ratios than progeny of normal birds previously selected on the .4% salt environment, with ratios approximately 20% greater from 0 to 2 days in Generation 4 progeny. Feed efficiencies were similar within genotype across selection environments. However, feed efficiency of dwarfs appeared to be superior to feed efficiency of normals from 0 to 8 days, whereas at later ages, normals were more efficient. Normal females of lines selected in the 1.6% salt environment had from 13 to 29% less abdominal fat percentages than contemporaries from lines selected on the .4% salt environment at 63 to 66 days of age. Abdominal fat weights of dwarfs, however, were not influenced by the selection environment.