Submitted to: Proceeding of Plains Nutrition Council Symposium
Publication Type: Proceedings
Publication Acceptance Date: April 15, 2000
Publication Date: N/A
Technical Abstract: A variety of studies relating to beef cattle feeding are in progress at the USDA-ARS-CPRL. We conducted trials to determine the effects of corn smut on the palatability, digestibility, and composition of corn silage. Smut infested silage had higher fiber, and protein concentrations, but lower total digestible nutrients. Uninfested silage had higher dry matter digestibility. When offered a choice, lambs preferred the infested silage over the uninfested silage. We conducted laboratory studies to determine the effects of soil amendments on ammonia emissions from a simulated feedyard surface. Alum (4 t/ac), calcium chloride (4 t/ac), the urease inhibitor NBPT (1 lb/ac) and humate (8 t/ac) decreased ammonia production by 90%, 70%, 60%, and 65%, respectively. The apparent utilization of phytate P by beef cattle is only 60% of that for dicalcium phosphate, suggesting that the utilization of grain P could be improved in ruminants. We conducted in vitro studies to determine utilization of P in a mutant low-phytate corn (optimum quality grains) compared to corn with normal phytate content. In vitro dry matter digestibility in a P deficient media was similar for both corns. The percentage of total P that was ater-soluble inorganic-P was affected by phytate content, pH, and processing method. Other scientists in our unit are conducting research in the following areas: 1) use of playas as runoff retention ponds, 2) effects of dust on animal health, 3) strategies to balance manure P and N inputs with crop requirements, 4) methods to decrease P runoff from fields, 5) use of manure as a fertilizer on native range, 6) ammonia flux from feedyards and fields, 7) decreasing viable bacteria and endotoxins in feedyard dust and runoff.