Influence of Strain of Chicken and Dietary Fat On Egg Production Traits

INFORMATION on the response of genetically different stock to high level of fat from different sources in the diet, and subsequent effect on egg production and egg traits, is quite limited. Donaldson (1962) added 30.4% animal fat to a standard laying ration and observed a decrease in rate of egg production which, he suggested, was due to a decrease in nitrogen retention. Schneider et al. (1962) showed that feeding as little as 200 mg./day/bird of Hazel Sterculia oil to White Leghorn pullets resulted in retardation of development of their reproductive system and inhibition of egg production. Beare et al. (1963) fed rats a mixture of palm oil and Swedish oil at 20% of a purified diet for four weeks and observed that weight gains exceeded those obtained by feeding Polish rapeseed oil with similar erucic acid content but a lower percent of saturated fatty acids. They concluded that the characteristic . . .