Evaluation of the growth performance and meat quality of Mongolian lamb fed grass, hay or pellets of Inner Mongolian native grass

The major constraint for livestock production in the Inner Mongolian Plateau is a feed shortage in winter. The objective of this study was to compare and evaluate the growth performance and meat quality of juvenile Mongolian lambs fed Inner Mongolian native grass in three forms: grass, hay, or pellets. Sixty Mongolian non-castrated male lambs in good health of the same age (6 months) and with similar body weight (28.83 +/- 0.19 kg) were randomly divided into three groups that fed Inner Mongolian native grass, hay or pellets (5 lambs per pen). Fresh grass intake was higher than pellets intake, and hay intake was lower than pellets intake (both P < 0.05). The lambs in the hay group exhibited daily weight loss, while the daily weight gains of the lambs in the grass and pellet groups were increased (P < 0.05). The carcass weight, body weight before slaughter, net meat mass, loin muscle area, and fat thickness (FT, a measure of fat tissue thickness) were greater (P < 0.05) in sheep given the grass and pellet groups than in those given the hay treatment. Compared with the hay treatment, the marbling score, water loss rate, and the protein were significantly increased in the grass and pellet groups, whereas the fat, Ca, a*, and b* values were significantly decreased. The results indicate that feeding native grass or pellets is more beneficial than feeding Inner Mongolian hay for the growth performance and meat quality of Mongolian lambs.