Practical, Raw-Soybean Diets for Egg-Type Pullets

Abstract

Egg-type pullets, when 11 wk. old, were fed one of these practical-type diets: 14% protein corn, sorghum grain and oat-alfalfa meal-soybean meal diet (SBM); 12% protein sorghum grain-raw, unextracted soybean meal diet with supplemental methionine (RSBM + M) or without (RSBM). One group was fed the SMB diet from 11 to 22 wk. Two groups were fed the SBM diet from 11 to 14 wk., then from 15 to 22 wk., one group was fed the RSBM + M diet and the other the RSBM diet. At 23 wk. of age, half the pullets on each growing diet were switched to an 18% protein layer diet containing soybean meal (SBM); the other half, to an 18% protein diet containing raw, unextracted soybeans (RSBM).Pullets fed the SBM diet had the highest percent change in body weight between 11 and 22 wk.; those fed RSBM diet, the lowest (106.4 to 88.4%). Supplemental methionine partially reduced the depressing effect of raw, unextracted soybean meal on growth. Both growing and laying diets significantly affected sexual maturity (age at 50% production) and hen-day rate of lay. Ages at sexual maturity were 26.1, 25.1, and 24.7 wk., respectively, for birds fed RSBM, RSBM + M, or SBM growing diets.Hen-day production percentages were 56.8, 60.3, and 64.0, respectively, for birds fed RSBM, RSBM + M, or SBM growing diets; the percentages for birds reared on RSBM + M diet and switched to SBM layer diet nearly equaled that of birds fed SBM diet during both growing and laying periods (68.3 to 70.3).