X. Qiu, M. L. Eastridge1, and Z. Wang
The Ohio State University Department of Animal Sciences
Eight intact multiparous cows and four cannulated primiparous cows were fed four diets in a 4 x 4 Latin square design: (1) 17% forage NDF (FNDF) with brown midrib (BMR) corn silage (CS), (2) 21% FNDF with BMRCS, (3) 17% FNDF with conventional CS (CCS), and (4) 21% FNDF with CCS. About 75% of the forage was from CS and 25% from alfalfa hay. The CCS and BMRCS contained 7.8 and 7.7% CP, 41.1 and 41.6% NDF, and 2.3 and 1.1% lignin, respectively. Diets contained 17.4% CP and 38.5% NDF, with soyhulls providing 23.4 and 17.8% of DM for 17 and 21% FNDF diets, respectively. Each period consisted of four weeks for intact cows and two weeks for cannulated cows. For intact cows, DM intake was higher for BMRCS than CCS, and milk urea nitrogen (MUN) was higher for cows fed 21 than 17% FNDF. Milk protein yield tended to be higher and MUN lower for cows fed BMRCS than CCS. Milk yield, milk fat yield, and milk protein percentage were similar among treatments. For the cannulated cows, physical effects of forage were not compromised by feeding BMRCS based on ruminal pH, mat consistency, and volatile fatty acids (VFA). There were no adverse effects of feeding BMRCS in a low FNDF diet with starch concentration of 32.7%.
1 For more information, contact at: The Ohio State University, 221B Animal Science Building, 2029 Fyffe Road, Columbus, OH 43210, 614-688-3059, Fax 614-292-1515, e-mail: eastridge.1@osu.edu