Effects of Dietary Energy Substitutions on Reproductive Performance, Feed Efficiency, and Lipogenic Enzyme Activity on Large White Turkey Hens

Abstract A 16-week trial was conducted with Large White turkey hens to ascertain the effect of deleting dietary carbohydrate calories on reproduction, lipogenic enzyme, and liver metabolite concentrations. Thirty percent of the carbohydrate calories (ground corn) were removed and isocalorically substituted with additional fat, 1,3-butanediol, or glycerol so that effects could not be attributed solely to deleting carbohydrates. Additional fat increased efficiency of feed utilization. Additional fat also decreased the activities of isocitrate dehydrogenase, malic enzyme, and fatty acid synthetase. Likewise, additional fat increased the liver lactate, malate, and oxaloacetate concentrations but decreased liver lipid. The addition of butanediol increased efficiency of feed utilization but increased embryonic mortality and decreased malic enzyme and fatty acid synthetase activities. Glycerol appeared to be metabolized similarily to carbohydrate and to promote liver lipid synthesis. Additional fat increased the protein/DNA ratio in the liver and decreased liver lipid.