Glandless Cottonseed Meal for Laying and Breeding Hens and Broiler Chicks

Abstract

The Acala C-9 variety of glandless cottonseed meal (GCSM) was tested for available gossypol in a 100-day feeding trial with laying hens. Corn-soybean diets incorporating GCSM at 10 and 20% were compared with diets formulated with Acala SJ-5, a commercially available cottonseed meal (CSM), at 10% and a control diet with no CSM. Each diet was fed to 25 hens. No detectable gossypol was found in the yolks of eggs from hens fed GCSM or the control diet, but gossypol was present when hens were fed the diet with CSM. Egg yolk discoloration in an ammonia atmosphere was noted in all of the eggs tested from the CSM-fed hens but only at a very low incidence in eggs from other groups. There were no differences between any of the four treatments in percent egg production, average egg weight, or hatchabihty. Broiler chicks were fed for 19 days diets with GCSM as the sole source of protein to determine the limiting amino acids. The diets contained 23% protein, 3200 kcal metabolizable energy/kg, and National Research Council levels of vitamins and minerals. Diets were supplemented with lysine, methionine, leucine, and isoleucine from 0 to .5% and were kept isonitrogenous with glutamic acid. Only lysine was limiting in GCSM for chick growth. Chick weights did not differ significantly from those fed an adequate reference diet if .3% lysine was added.