Journal of Animal Science, Vol 74, Issue 7 1728-1735, Copyright © 1996 by American Society of Animal Science

JOURNAL ARTICLE

Digestibility and utilization of pearl millet diets fed to finishing beef cattle

G. M. Hill, G. L. Newton, M. N. Streeter, W. W. Hanna, P. R. Utley and M. J. Mathis
Department of Animal and Dairy Science, University of Georgia, Tifton 31793-0748, USA.

Pearl millet grain was blended with corn in 1:1 or 2:1 ratios in beef finishing diets fed in two metabolism and two feedlot trials. In Exp. 1, diets contained 1) 79.5% corn and 4.5% soybean meal (C-SBM), 2) 28% corn, 54.5% sorghum, and 1.5% soybean meal [GSC(2:1)], and 3) 28% corn and 56% pearl millet [PMC(2:1)]. In Exp. 2, diets contained 1) 81.5% corn and 3.5% soybean meal (C-SBM) or 2) 42.5% corn and 42.5% pearl millet [PMC(1:1)]. Diets fed to steers in metabolism trials in Exp. 1 and 2 had similar (P > .10) apparent digestion coefficients for OM, crude fiber, NDF, and ADF. However, ether extract digestibility was higher (P < .05) for C-SBM than for GSC(2:1) and PMC(2:1) in Exp. 1, and it was higher (P < .10) for C-SBM than for PMC(1:1) in Exp. 2. In both experiments CP digestibility was higher (P < .10) for C-SBM diets, and N retention was similar (P > .10) for diets within each experiment. In each experiment, TDN calculated from apparent digestion coefficients was converted to NEm and NEg. The TDN, NEm, and NEg were lower (P < .10) for GSC(2:1) and PMC(2:1) than for C-SBM in Exp. 1. Experimental diets were fed to steers (n = 45; 396 +/- 19 kg initial BW; 70-d ad libitum feeding) in Exp. 1 and to heifers (n = 30; 318 +/- 15 kg initial BW; 92-d ad libitum feeding) in Exp. 2. The ADG, empty body weight gain (EBG), and predicted EBG were not different (P > .10) for diets composed of the different grain sources. Feed DMI and DM per gain were higher (P < .05) for PMC(1:1) than for C-SBM in Exp. 2. Pearl millet supplied approximately 88% as much NEm and 85% as much NEg as the corn-SBM portion of diets having similar CP concentrations.