Mechanisms of Programmed Nutrition in Finishing Cattle \u3ci\u3e in Vivo \u3c/i\u3e and Ruminal Parameters of Amaize Supplementation \u3ci\u3e in Vitro\u3c/i\u3e

Programmed Nutrition Beef Program (Alltech Inc.) is a dietary supplement that contains Aspergillus oryzae fermentation extract with α-amylase activity that could reduce the use of feed additives such as monensin and tylosin in conventional feedlot diets. This study examines the changes in rumen fermentation resulting from feeding monensin/tylosin and Programmed Nutrition Beef Finisher. The goal was to determine if these shifts in rumen fermentation contribute to the Programmed Nutrition response observed in vivo. This study also analyzes how different levels of α-amylase (Amaize)supplementation impacts feedstuff degradation and utilization in vitro. In vivo experiment used eight steers in a replicated 4 x 4 Latin square design, and measured heat production, ruminal pH, and ruminal volatile fatty acid (VFA) concentrations for 48 hours. The in vivo study measured by urine and fecal output; dietary digestibility, nitrogen balance, 15N-glycine protein turnover, and energy balance. In vitro experiment used rumen fluid from three cannulated steers to measure in vitro gas production, rate of degradation, and starch degraded for different feedstuffs with or without Amaize. In vivo study determined that inclusion of Programmed Nutrition did not increase average daily gain, ruminal pH, ruminal VFA production, nitrogen digestibility, or methane production. Feeding Programmed Nutrition with monensin and tylosin can decrease acid detergent fiber (ADF) digestibility. In vitro study determined that in vitro gas production after 24-h increases when dry rolled barley is incubated with Amaize. Rate of degradation increases when dry rolled corn, corn steam-flaked at 26 lb/bu, retrograde steam-flaked corn, and steam-flaked barley are incubated with Amaize. Starch degraded after 2-h incubation increases when steam-flaked corn and retrograded steam-flaked corn are incubated with Amaize