Influence of Formaldehyde Treatment of Soybean Meal on Performance of Growing Steers and Protein Availability in the Chick

Soybean meal (SBM) treated with 0 .3, .6 or .9% formaldehyde by weight was used to study the influence of level of formaldehyde treatment on in vitro protein degradation by rumen microorganisms, protein availability in the chick and performance of growing steers. Formaldehyde treatment of SBM reduced ammonia concentrations after 2, 4 and 8 hr of in vitro incubation in rumen fluid. Growth and feed efficiency in the chick were not affected by treating of SBM with .3% formaldehyde, but higher levels of formaldehyde depressed chick performance. Ninety steers were used in a 90-day feeding study to determine whether treating SBM with formaldehyde increased gain or improved efficiency of feed utilization. Steers (268 kg initial weight) were randomly allotted according to breed to five dietary treatments and fed high energy diets ad libitum. Four of the experimental diets contained .2% urea and 5.3% SBM treated with 0 (negative control), .3, .6 or .9% formaldehyde. The fifth diet (postive control) contained .3% urea and 7.5% untreated SBM. During the 90-day study, steers fed the positive control diet gained 12.2% faster than steers fed the negative control diet. Steers fed the diets containing formaldehyde-treated SBM gained in a manner similar to those fed the positive control diet. Feed efficiency tended to be lower for steers fed the negative control diet compared to all other diets. Serum urea-nitrogen and rumen fluid ammonia nitrogen concentrations were higher in steers fed the positive control diet than in those fed the negative control diet. Formaldehyde treatment of SBM resulted in a significant linear and quadratic decrease in serum urea-nitrogen concentrations with increasing levels of formaldehyde. Results suggest that treatment of SBM with formaldehyde can improve efficiency of feed utilization when high energy diets are fed to growing steers.