Abstract:

This experiment was conducted to study the effects of different energy levels on the growth performance and slaughter performance of Alpine Merino and South African mutton Merino crossbred F₁ (Gao × Nan F₁) weaned lambs. A single factor randomized trial design was adopted. Forty-five male lambs of Gao× Nan F₁ generation were selected and divided into high, medium and low energy groups. The feeding experiment was conducted for 104 days to determine the growth indexes, slaughter performance and meat quality indexes. The results showed that with the increase of feeding period, the body weight of lambs in medium energy group increased significantly; the average feed intake and feed/gain of lambs in high and medium energy groups were significantly lower than those in low energy group (P<0.01); the live weight before slaughter of lambs in low energy group was significantly lower than that in high energy group and medium energy group (P<0.01); the carcass weight of lambs in high energy group was significantly higher than that in low energy group (P<0.05); the slaughter rate of lambs in medium energy group was significantly lower than that in low energy group (P<0.05). The results show that the minimum metabolizable energy level of Gao× Nan F₁ lambs was 10.10 MJ/kg, which could promote the growth and development of lambs and nutrient digestion and absorption.

Key words: South African mutton Merino, Alpine Merino, energy level, fattening performance