Effect of Feeding Soybeans or Formaldehyde-Treated Soybeans on Lipid Metabolism in Ruminants

Abstract

Three lactating fistulated goats were used in a 3 × 3 Latin Square design comparing control, formalin-treated, and untreated soybean rations. The concentrate-to-roughage ratio was 2:1. Milk yield was depressed (P < .05) in the formalin-treated soybean group. Long chain unsaturated milk fat fatty acids increased in both soybean treatments compared to controls with no significant difference between treated and untreated beans. Rumen pH and total protozoa counts were lower on the goats fed formaldehyde-treated beans. Total rumen lipids were elevated over controls in both treatments. Unsaturated 18 carbon fatty acids in the rumen lipids were higher with the treated soybeans compared to the untreated beans, suggesting some protection of the soybean lipids from hydrogenation. The inclusion of soybeans appeared to depress butyrate production and significantly increase propionate production in the rumen. Circulating blood acetate was depressed (P < .05) with the formaldehyde treatment. Plasma and fecal lipid levels and milk fatty acids suggested that the soybean lipids were being utilized in both treatments but with no distinct advantage for the treated soybeans. © 1971, American Dairy Science Association. All rights reserved.