Performance, fecal egg count and feeding behavior of lambs grazing elephant grass (Pennisetum purpureum Schum.) with increased levels of protein supplementation

Abstract

The current study investigated the effect of increased protein supplementation levels on fecal egg count, performance and feeding behavior of lambs grazing elephant grass (Pennisetum purpureum Schum.). The treatments consisted of five levels of crude protein (CP) in an isoenergetic supplement (0%, 8%, 16%, 24% and 32% CP) provided to growing lambs. Fifty lambs at initial live weight of 20.2 ± 2.94 kg were slaughtered after 75 days of protein supplementation. Ether extract intake decreased with the increase of CP in the supplement. Average daily weight gain was over 60% greater for lambs receiving supplement with 16% and 24% CP than lambs in the control group. Protein supplementation did not affect grazing and ruminating behavior but lambs in the control group spent from 82% to 88% less time eating the supplement (4.01 min; P < 0.01) and visited the supplement trough 3.01 times a day. Fecal egg count remained low with the increase of protein in the supplement in the beginning of the grazing period. Intake, weight gain, carcass length and rump width of the lambs enhanced as CP in the supplement increased, with optimal performance obtained with 8% CP in the supplement for lambs grazing elephant grass.