Phosphorus requirements of poultry. V. The effects during the subsequent laying year of feeding growing diets containing no animal protein or supplementary phosphorus.

Abstract

Synopsis Pullets reared to 18 weeks of age on diets containing no feeding stuffs of animal origin and without phosphorus supplementation showed no significant difference in egg yield compared with similar pullets fed rearing diets containing animal protein and added phosphorus. During the laying stage, diets in commercial use at this centre gave significantly higher egg yields, better average egg prices due to superior grading results and a higher margin over food cost than the same diets modified to conform with the nutrient recommendations of the National Research Council of America (1960). Where the supplementary protein in both types of layers' diet was of vegetable origin, egg yield, food cost and margin of income over food cost were all significantly inferior to groups fed comparable diets containing supplementary protein of both vegetable and animal origin. Soyabean meal and sunflower seed meal gave significantly poorer results when used in combination as the sole protein supplement compared with soyabean meal plus methionine.