Grazing pressures and animal production from pearl millet cv. Comum

Abstract

A trial was conducted at the Estação Experimental Agronômica of UFRGS, Guaíba, RS, Brazil, to evaluate the average daily liveweight gain/ha of two kind of steers, Zebu crosses and Charolais crosses grazing pearl millet (Pennisetum americanum (L.) Leeke) at four levels of grazing pressure (GP) (4%, 6%, 8% and 10% B.W.) and expressed by different uneaten residues left on the pasture treatments. The pasture evaluation was made by botanical composition, crude protein (CP) content, and in vitro organic matter digestibility (IVODM). The higher levels of GP reduced the contribution of pearl millet and increased the participation of Cynodon dactylon (L.) Pers, in the botanical composition of pasture forage dry matter. The daily liveweight gain per animal ranged from 0.50 kg to 1.24 kg/animal, showing a positive linear relationship to the different pasture residue levels, for the Zebu crosses. The animal/days/ha ranged from 334 to 604 while liveweight gain/ha was raised from 259 kg to 572 kg/ha, with a P > .05 for animal/days/ha. The CP values decreased from 15% to 5.4% with dry matter residues causing a reduction in IVODM from 72% to 45% with a P <0.05 for the IVODM among the different periods.