EFFECT OF HIGH-FIBER ENERGY SUPPLEMENTS ON NUTRIENT DIGESTIBILITY AND MILK-PRODUCTION OF LACTATING DAIRY-COWS

Sixteen multiparous Holstein cows past peak lactation were used in a 4 x 4 Latin square design replicated four times to determine the production response and digestibility of diets containing high fiber energy supplements. Corn gluten feed, soybean hulls, or wheat middlings were substituted for a portion of corn, soybean meal, and corn silage in the control diet to provide 22% of the total dietary DM. Intake of DM was decreased when cows consumed wheat middlings compared with control and soybean hulls. Actual milk and SCM yields and milk fat percentage were not different among treatments. Milk protein percentage was greater when cows consumed corn gluten feed compared with soybean hulls. Apparent digestibility of DM was greater when cows consumed soybean hulls compared with wheat middlings. Intake and apparent digestibility of ADF and NDF were greatest when cows consumed soybean hulls. Cows consuming wheat middlings had intermediate intake and decreased apparent digestibility of NDF compared with controls. Intake and apparent digestibility of NDF were not different when cows received corn gluten feed compared with control or wheat middlings. High fiber energy supplements supported milk production equally; however, differences in DM and nutrient intake, milk composition, and nutrient apparent digestibility were significant.