Influence of Nonenzymatically Browned Soybeans on Ruminal Fermentation and Lactational Performance of Dairy Cows

Abstract

Four ruminally fistulated Holstein cows were assigned to one of four total mixed rations (TMR) in a 4 × 4 Latin square with 3-wk periods to investigate the effects of added lipid from nonenzymatically browned soybeans or soybean oil on ruminal metabolism and milk fatty acids. All rations contained 50% forage and 1) 4% added lipid from soybean oil, 2) 4 or 6% added lipid from nonenzymatically browned soybeans, or 3) no added lipid (control). The TMR that contained nonenzymatically browned soybeans increased milk C18:2 by 35% compared with the TMR that contained soybean oil. A lactation trial was conducted in which 60 Holstein cows were assigned to one of five TMR from wk 3 to 18 of lactation. The TMR contained 1) 4.5% added lipid from soybean oil, 2) 1.5% added lipid from nonenzymatically browned soybeans and 3% from soybean oil, 3) 3% added lipid from nonenzymatically browned soybeans and 1.5% from soybean oil, 4) 4.5% added lipid from nonenzymatically browned soybeans, and 5) 4.5% added lipid from Ca salts of long-chain fatty acids. Dry matter intake was reduced by 11% for cows fed the TMR containing soybean oil only compared with that for cows fed the other TMR. Milk C18:2 and C18:3 were increased as the inclusion of nonenzymatically browned soybeans in the TMR increased. All percentages of the nonenzymatically browned soybeans fed to cows resulted in fat-corrected milk yields that were similar to those of cows fed the TMR that contained Ca salts of fatty acids.