Improving Rumen By-pass of Soybean Meal

Soybean meal was coated with different lipid sources to protect against bacterial degradation in the rumen. Rumen fistulated steers were fed a diet composed of 10% alfalfa hay, 50% wheat straw, 20% ground corn and 20% soybean meal or soybean meal coated with 20% soapstock, and digestibility of the diet was tested. Samples of rumen content were obtained at 0, 2, 4, 6 and 8 hours after feeding for pH, ammonium–nitrogen and volatile fatty acid determination. Results indicated that coating the soybean meal with soapstock had no significant effect on rumen pH or volatile fatty acid levels. A significant reduction in ammonium-nitrogen concentrations was observed for the soapstock coated soybean meal treatment. Ammonium-nitrogen reductions of 21, 25 and 27.5 percent were observed for the 2, 4 and 6 hour post-feeding samples, respectively. These results indicate that coating soybean meal with soapstock will improve rumen-bypass of the soy protein. Additional research is needed to determine whether the increased protein bypass of the soy protein can result in improved performance of beef and dairy animals.

Manterola, H.B. , D.A. Cerda and J.J. Mira. 2001. Protein degradation of soybean meal coated with different lipid substances and its effect on ruminal parameters when included in steer rations. Animal Feed Science and Technology 92(3-4):249-257.