Effect of plane of nutrition during the growing phase, source of cereals, fat and the methionine content of laying diets on the performance of crossbred pullets

Abstract

A factorial experiment was carried out to examine the effects of two planes of nutrition during the growing phase and laying diets with or without barley, added methionine and with either mixed tallow or rapeseed oil, on the performance of crossbred pullets. Pullets fed during the growing phase on a diet where lysine and energy contents were lower than normally recommended ate less feed, cost less per pullet, had lower liveweights and matured later than those grown on a high plane. Mortality was not affected by the plane of nutrition. During the laying phase, pullets grown on a low plane laid more eggs, converted feed to eggs more efficiently and gained liveweight at a faster rate but were still lighter at 72 weeks of age than those reared on the high plane of nutrition. Egg weight and feed intake were not affected by the plane of nutrition during the growing phase. The cereal composition of diets that contained added fat had no effect on egg weight and egg production. Birds fed barley plus wheat based diets had a higher feed intake and liveweight. Addition of 0.06 per cent methionine to a layers diet based on oats plus wheat caused a depression in egg production which was more apparent in the presence of rapeseed oil. Supplementary methionine also depressed hen-housed production and feed intake but egg weight was unaffected. Rapeseed oil as compared with mixed tallow depressed egg weight, feed intake, and percentage of large eggs.