Effect of Raw or Roasted Whole Soybeans on Digestibility of Dietary Nutrients and Milk Production of Lactating Dairy Cows

Twenty-four multiparous Holstein cows were used in a 12-wk trial with a split-plot design to determine the influence of raw or roasted whole soybeans on the perfonnance of lactating cows. Treatments consisted of three isonitrogenous, isocaloric total mixed rations supplemented with soybean meal, raw whole soybeans, or roasted whole soybeans included at 9.4% of the ration OM. Intake of ether extract was greater when cows consumed soybeans and when roasted soybeans were fed compared with raw soybeans. Intake of ADF tended to be higher when soybeans were included in the diet. Intake of NDF tended to be higher with roasted whole soybeans than raw soybeans. Apparent digestibility of OM and CP tended to be higher and ether extract, ADF, and NDF greater when soybeans were fed. Apparent digestibility of OM and ADF tended to be higher and CP greater for diets containing raw soybeans compared with roasted soybeans. Inclusion of soybeans improved ether extract and fiber intake and apparent nutrient digestibility, but did not change milk yield and composition. Roasted soybeans did not provide any additional benefit over raw soybeans.