Nutritional evaluation of soybean meals varying in oligosaccharide content.

Three conventional soybean meals (CSBM) and five low-oligosaccharide soybean meals (LOSBM) were evaluated. Meals were prepared by solvent-extracting flakes from generic soybean lines and soybean lines genetically modified to contain varying oligosaccharide content. The mean raffinose, stachyose, and galactinol levels in the CSBM were 0.58, 3.23, and 0%, respectively. The mean (range) raffinose, stachyose, and galactinol levels in the LOSBM were 0.08 (0.03 to 0.17%), 0.42 (0.04 to 1.08%), and 0.104 (0 to 0.24%), respectively. The crude fiber, fat, and ash contents of all SBM were similar, whereas the CP and sucrose contents of the LOSBM were slightly higher than the CSBM. The effect of SBM type on digesta passage rate, dry matter digestibility, and TMEN was assessed in conventional and cecectomized roosters using a precision-fed rooster assay (8 x 2 factorial design). Quantitative collection of excreta for 4, 8, 12, 16, 20, 24, and 48 h postfeeding indicated little or no effect of SBM type on digesta passage rate. The dry matter digestibility and TMEN values for the SBM were lower for cecectomized roosters compared with conventional roosters (P < 0.05), and there was no significant SBM x bird type interaction. The mean TMEN values (kcal/kg DM) for the CSBM and LOSBM were 2,739 and 2,931, respectively, which was a difference of 7% (P < 0.05). The two LOSBM with the lowest total raffinose, stachyose, and galactinol levels (0.07% and 0.25%) had average TMEN values that were 9.8% (P < 0.05) higher than their respective genetic controls. Digestibilities of raffinose and stachyose were much higher (P < 0.05) in conventional roosters than in cecectomized roosters. The results of this study indicated that the TMEN of LOSBM was higher than that of CSBM.

The use of high oil corn in broiler diets.

We examined the effect of substituting conventional corn (CC; 3.5% crude fat) with high oil corn (HOC; 8.81 and 6.75% crude fat) on broiler performance. In Experiment 1, 100 chicks were assigned to 16 experimental pens consisting of two treatments. Treatment 1, the control group used CC, whereas in Treatment 2, CC was totally replaced with HOC containing 8.81% crude fat. In Experiment 2, 52 chicks were assigned to each of 16 experimental pens divided also into two treatments. Treatment 1 was the control group using CC and in Treatment 2 CC was totally replaced by HOC (6.75% crude fat). Body weight, cumulative feed intake, and feed efficiency were determined weekly for each pen from 7 to 42 d of age. Carcass weight and percentage yield were determined prechill. Results in Experiment 1 showed no significant differences for any parameter measured. In Experiment 2, body weight was significantly higher (P < 0.05) for birds fed HOC at 42 d of age. There were no significant differences among treatments for the remaining parameters. These results indicate that comparable performance of broilers can be obtained when CC is substituted with HOC.

Availability of amino acids in high-oil corn.

True digestibility of amino acids, bioavailability of Lys, and TMEn in three types of high-oil corn (HOC) and one conventional corn (CC) were determined. The CC, HOC1, HOC2, and HOC3 contained 4.3, 5.9, 6.6, and 9.5% ether extract, respectively, on a DM basis. True digestibility of amino acids was determined using the precision-fed cecectomized rooster assay in which each corn sample was tube-fed (30 g) to nine roosters and excreta were collected for 48 h. True digestibility of most amino acids in HOC2 and HOC3 were significantly higher (P < or = 0.05) than those in CC and HOC1. Mean digestibility of 15 amino acids in HOC2 and HOC3 was 91% compared to 80% for CC and HOC1. The TMEn values (kilocalories per gram DM) of CC, HOC1, HOC2, and HOC3 were 3.883, 4.024, 4.038, and 4.140, respectively. Lysine bioavailability was assessed using a slope-ratio chick growth assay in which a Lys-deficient crystalline amino acid diet was supplemented with 0, 0.1, or 0.2% L-Lys from L-Lys x HC1 to provide a standard curve. Six additional dietary treatments consisted of supplementing the basal diet with 28 or 56% of CC, HOC2, or HOC3. The nine diets were fed to four replicate groups of six chicks from 8 to 18 d posthatching. Lysine bioavailability was calculated using multiple regression slope-ratio methodology where Y was weight gain and X was intake of Lys from the L-Lys x HC1 or a corn. Supplementation of the basal diet with L-Lys x HC1, CC, HOC2, or HOC3 yielded linear (P < or = 0.001) growth responses. Bioavailability values (percentage) for the Lys in CC, HOC2, and HOC3 relative to the Lys in L-Lys x HC1 were 65 +/- 10, 72 +/- 10, and 91 +/- 8, respectively. The results of this study indicated that digestibility of amino acids and bioavailability of Lys in HOC are equal to or greater than those in CC.