Beef-Forage Program

Comparison of corn and soybean hulls for supplementing lactating beef cows fed free choice bermudagrass hay.

David G. St. Louis, Animal Scientist; Randall D. Little, Agricultural Economist; Ned C. Edwards, Agronomist/Superintendent

Background: Approximately half the annual cost of maintaining beef cows is winter feeding. While ryegrass for winter pasture reduces the cost of supplements and hay, early ryegrass pasture is still expensive, costing over $100 per acre. Previous attempts to supplement locally produced hay fed free choice have not been successful because the associative affects of hay and grain have not been adequately accounted for in equations for balancing of diets (Higgins, et al. 1991; Garces-Yepez, et al. 1997). The National Research Council has revised the nutrient requirements for beef cattle (NRC, 1996). However, problems still remain that do not explain the differences between various supplements to bermudagrass hay and pasture. This research compared corn and soybean hulls as supplements to bermudagrass hay for lactating beef cows and compared ryegrass pasture to hay and grain supplements for lactating beef cows in South Mississippi.

Research Findings: Cows and calves with free access to ryegrass pasture , PAST, made the most rapid gains from calving until availability of summer pasture compared to cows and calves being offered bermudagrass hay free choice and supplemented with either corn or soybean hulls. The amount of daily supplements fed to treatments CORN and HULLS were based upon the 1996 NRC Nutrient Requirements of Beef Cattle (NRC, 1996) so that cows and calves should have performed the same, but they did not. Gains of cows and calves were more rapid for the HULLS treatment than for the CORN treatment. In 1998 cow gains were 138, 70 and 21 lbs for PAST, HULLS and CORN, respectively, while calf gains were 185, 172 and 144, respectively, in 95 average days past calving. In 1999 cow gains were 86, 81 and 32 lbs for PAST, HULLS and CORN, respectively, while calf gains were 151, 128 and 111 lbs, respectively, in 60 average days past calving. There was no apparent difference between treatments in hay intake. In 1998 bermudagrass hay was 52% TDN and 12.6% crude protein. In 1999 hay was 46% TDN and 8.2% crude protein. In both 1998 and 1999 cows on the CORN treatment received 6.5 lb of ground shelled corn daily while the cows on the HULLS treatment received 13.0 lb of soybean hulls daily.

Application: Soybean hulls perform better than ground shelled corn as supplement to bermudagrass hay for wintering beef cows. However, more soybean hulls are required to equal the energy of corn. In general, when NRC energy and protein requirements are met, it seems that supplements with lower and/or less rapidly degraded energy content perform better. The reason is not clear indicating the need for more in depth research.

References:
Garces-Yepez, P., W.E. Kunkle, D.B. Bates, J.E. Moore, W.W. Thatcher and L.E. Sollenberger. 1997. Effects of supplemental energy source and amount of forage intake and performance by steers and intake and diet digestibility by sheep. J. Animal Sci. 75:1918.

Higgins, R.K., J.E. Moore and W.E. Kunkle. 1991. Effect of limited grain supplement on bermudagrass hay intake and gain by steers. p. 189. Proc. 2nd Grazing Livestock Nutrition Conf. Steamboat Springs, CO.