Dietary Energy and Fat Content as Factors in the Nutrition of Developing Egg Strain Pullets and Young Hens

One hundred and twenty six commercial White Leghorn pullets were housed in cages at 23 weeks of age and fed two laying diets that in energy and fat content. Changes in hepatic "citrate-cleavage" and "malic" enzyme activity and changes in liver and body chemical composition were measured each week during the first 20 weeks of lay. Average daily caloric intake was greater for the birds fed the high energy laying diets even though these birds consumed 11% less feed. While energy content of the laying diet failed (P = 0.05) to affect body weight gains, liver weight, liver fat content and hepatic enzyme activity, significant (P = 0.05) increases in abdominal fat pad weight and total body fat content were noted. The findings of significant alterations in total carcass composition in birds receiving the high energy laying diet support the conclusion that energy content of the layer diet will influence the carcass composition of modern day egg producing strains.