Evaluation of Corn Hybrids Selected to Improve Silage Use by Growing Steers and Characterizing Digestion of Novel Sweet Bran Plus Products from Corn Wet Milling

Three studies were conducted to evaluate corn silage hybrids selected for improved fiber and starch digestion on growing steer performance and nutrient digestion, and to characterize digestion traits of novel sweet bran plus products from corn wet milling. In experiment 1, diets consisted of 80% DM of corn silage hybrid Masters Choice MCT6365 RIB (MC1, selected to improve fiber and starch digestion), MCT6733 GT3000 (MC2, selected to improve fiber digestion), and Pioneer® 1197AM (CON, a conventional corn hybrid commonly grown in Eastern Nebraska) were compared in an 84-day cattle growing study. In experiment 2, the same diets were used to evaluate rumen fermentation and nutrient digestion. Experiment 3 evaluated three novel Sweet Bran Plus products (A, B, and C) from corn wet milling on rumen fermentation, nutrient digestion, and rumen bacterial community structure in beef cattle. In experiment 1 and 2, feeding MC1 corn silage improved organic matter digestion (P = 0.02), starch digestion (P \u3c 0.01), and energy availability (P ≤ 0.07) to the steers, which allowed for greater average daily gain (P = 0.09) and improved feed efficiency (P \u3c 0.01). In experiment 3, feeding Sweet Bran Plus A resulted in better digestion of starch and NDF than product B and C, and greater starch content of product B and C resulted in less acetate to propionate ratio and less digestion of starch and NDF. Sweet Bran Plus products had minimum effect on energy digestion, ruminal pH, rumination and blood parameters. Rumen bacterial microbiota were altered by different Sweet Bran Plus products and inclusion. Digestion trait differences existed among different corn hybrids, as well as among different sweet bran plus products. Further evaluation is necessary to improve their use in the cattle industry