Studies in this report examined the possibility of utilizing soybean meal processed to a higher urease value for broiler chickens. Such meals might be produced with lower energy costs and possible savings to the feed manufacturer. Untoasted, solvent-extracted dehulled soybean flakes were subjected to differing cooking times in an autoclave and in a steam-jacketed mixer with steam sparging to produce flakes with a range of urease values.Results of these studies indicate that soybean flakes with urease in excess of .2 pH rise were acceptable for use in diets for broiler chickens. A pH rise of up to .5 units, similar to that used by the European Economic Community, would appear justified for soybean meals processed for broiler chickens. (

No abstract

Three trials were conducted to estimate the threonine (Thr) requirement of male broiler chicks. Chicks 7 days of age were fed a grain sorghum-soybean meal diet containing .59% Thr, supplemented with 0, .05, .09, .15, .22, .27, or .28% L-Thr. Levels of basal and supplemental amino acids were confirmed by ion-exchange chromatography. Diets were fed for 18 or 20 days, depending upon the trial. A corn-soybean meal diet analyzed to contain .90% Thr was used for comparison. Results of the three trials were pooled for determination of Thr requirements. A significant improvement in gain was observed when the basal grain sorghum-soybean meal diet was supplemented with .09% supplemental Thr (total .68% Thr). No further improvements in gain were observed at higher levels of Thr supplementation. Body weight gain of chicks fed the Thr-supplemented diets did not differ significantly from that of chicks fed the corn-soybean meal control diet. For maximum feed utilization, the Thr requirement was .79%, as estimated by regression analysis. This is in agreement with the .80% requirement suggested by the National Research Council in 1984. Feed utilization of chicks fed the corn-soybean meal diet was significantly better than that of chicks fed any of the grain sorghum-soybean meal diets regardless of the level of Thr supplementation.

Two experiments were conducted in which zeolites were added to broiler diets at the 1% level beginning at 21 days of age. In one study, diets with different energy levels were used to determine if an interaction existed between zeolite supplementation and nutrient density. No beneficial effects of zeolite supplementation on body weights were observed in either experiment. There were no statistically significant differences in feed utilization between diets with and without zeolites, and the numerical differences could be accounted for by the addition of 1% inert zeolite.(

Three experiments were conducted to determine the response of the male broiler chick to tryptophan (TRP) supplementation. Chicks were fed from 7 to 18 or 7 to 20 days posthatch either a grain sorghum-soybean meal diet containing .16% TRP, supplemented with 0, .02, .04, .06, .09, or .11% L-TRP, or a corn-soybean meal positive control diet containing .25% TRP. Levels of TRP in all diets were confirmed by ion-exchange chromatography using an alkaline hydrolysis. The test diet contained 15.34% CP (N x 6.25) from intact ingredients and 20% CP (N x 6.25) when supplemented with other amino acids to 110% of National Research Council recommendations in 1984. No improvement in gain or feed efficiency was observed with chicks fed the grain sorghum-soybean meal diet at any level of TRP supplementation. Feed utilization but not weight gain of the chicks fed the TRP-supplemented test diets was significantly poorer than that of chicks fed the corn-soybean meal positive control diets. These results suggest that the TRP requirement of the young (0 to 21-day-old) broiler chicken is no greater than .16% of a diet containing 3,200 kcal ME/kg.