Eastern Gamagrass: Determining its Role in the Feeding of Lactating Cows

Abstract

Cherney, D.J.R., Salon, P.R., Thompson, D. and Cherney, J.H. 2003. Eastern gamagrass: Determining its role in the feeding of lactating cows. J. Appl. Anim. Res., 23: 81–92. Two production trials were conducted to determine the role of eastern gamagrass (Tripsacum dactyloides (L.)L.) in the feeding of lactating cows. Two trials were conducted comparing eastern gamagrass total mixed ration (TMR) with corn silage TMR. At Cornell University, Ithaca, NY, a trial was conducted with 16 lactating Holstein cows (165.2±8.7 days in milk) milked three times daily. Twenty lactating Holstein cows milked twice daily were used at State University of New York (SUNY) Cobleskill. The Cornell University (CU) trial was a continuous trial with production parameters of the previous week used as a covariate. The SUNY Co leskill trial was a switchback design with 28d periods. Dry matter intake and milk production did not differ between the diets in either trial. Milk area nitrogen (MUN) was higher in the corn silage TMR than the eastern gamagrass TMR in the Cornell University trial. Milk fat, true milk protein and milk lactose did not vary in either trial. Results from this study indicate that eastern gamagrass can be used to replace the fiber coming from corn silage. This will result in considerably more grain being needed in the TMR, however, to offset the lower energy of eastern gamagrass. Whether or not this is economically or environmentally feasible will depend on the price of grain. Nutrient management aspects of possibly increasing feeds brought from off farm also needs to be considered.