Effect of degradable intake protein, harvest management, physical processing and genetics on utilization of corn, barley and whole-plant corn silage by beef cattle.

摘要

Four ruminally and duodenally cannulated steers were used to determine feed intake and in vivo digestibility of high-oil corn, typical corn, and typical corn with added oil. Intake of ME was greater for diets containing high-oil corn than typical corn; however, no difference in ME intake was seen between diets containing high-oil corn and typical corn with added corn oil. Caloric intake is the main factor affecting gain in feedlot cattle, therefore, similar intake of ME between high-oil corn and typical corn-based diets with added corn oil indicate that high-oil corn may be effective at replacing supplemental fat in beef finishing diets.; Two-hundred forty steers were used to determine the effect of grain type and level of DIP on feedlot performance and carcass characteristics of finishing cattle. Improved growth performance for corn compared with barley-fed cattle was largely associated with greater DM and energy intake. Acceptable growth performance and carcass quality of cattle fed predominantly barley finishing diets is dependent on management for optimal DM intake. Type of grain (or starch) did not impact growth response to supplemental DIP.; Four ruminally cannulated heifers were used to determine the main effects and interactions of corn hybrid (Pioneer 3223 and 3335) and cutting height (20 and 61 cm) on feed intake and total tract digestibility of corn-silage. Results showed nominal benefits in silage quality from harvesting at a greater cutting height would not justify the loss of DM yield per hectare due to additional stalk left in the field. Hybrid digestibility differences indicate genetics have a more important effect on digestibility of corn silage than cutting height.; Four ruminally and duodenally cannulated steers were used to determine the main effects and interactions of mechanical processing and urea supplementation on feed intake and in vivo digestibility of corn silage-based diets. Adding urea did not increase NDF digestion; however, synthesis of microbial protein increased when urea was added to the diets. Ensuring an adequate DIP supply when feeding corn silage-based diets may increase performance of beef cattle by stimulating increased microbial protein synthesis.