Rumen fluid profiles and environmental cost of production in weaned thin-tailed lambs given different levels of feeding

Abstract

This study was conducted to examine the effect of different levels of feeding on rumen fluid profiles and environmental cost of weaned Thin-tailed lambs. As many as 21 weaned male lambs were allocated into 3 feeding levels in a completely randomized design. The treatments were low (4% BW; T1), medium (5.5% BW; T2) and high feeding level (ad libitum; T3). Each treatment consisted of seven replicates. This study showed that lambs fed T3 had highest dry matter intake (DMI; 7.9%BW; 1516g/d) than that of T1 and T2 which were significantly different (p<0.05). The digestibility was similar in all treatments (averaged 60.21%; p>0.05). Lambs fed T3 had higher acetate (112.86 mM), propionate (41.14 mM), and butyrate (31.30 mM) concentrations at 6h after feeding (p<0.05). There was no significant effect of feeding levels on ammonia concentrations of rumen fluid at (p>0.05). Microbial nitrogen production of lambs was not significantly different (averaged 2.69 g/d; p>0.05). Lambs given T3 had the highest ADG (202 g/d; p<0.05) and the lowest methane emission production per unit body weight gain (0.54 L/gADG; p<0.05). In conclusion, the rumen fluid ammonia and VFA in the lamb are stable at high feeding level. The environmental cost of lamb fattening is lower when the lamb is kept under a high feeding level (ad libitum).