LAUSR

Abstract This study was carried out in an attempt to evaluate the impact of Broussonetia papyrifera as a roughage substitute at different levels on carcase traits, growth performance, meat quality and immune performance in Hu ram lambs. Sixty Hu rams (5 months of age, 26.70 ± 2.14 kg body weight) were randomly divided into four groups. The treatments comprised B. papyrifera supplementation at levels of 0% (G0), 30% (G30), 60% (G60) and 100% (G100) of roughage feed. The results suggested that diet supplemented with B. papyrifera (G100 group) caused a higher average weight gain (AWG) and average daily gain (ADG) than those of G0 group. The highest carcase weight was observed in the G60 group. The chemical and physical properties of the longissimus dorsi muscle of Hu rams showed no significant differences (p>.05). For fatty acid, the G60 group had significantly lower content of saturated fatty acids (SFAs), higher contents of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) and higher PUFA/SFA ratio than other groups (p<.05). In terms of the immune response, G60 and G100 groups significantly showed a significant rise in the immunoglobulins (IgG, IgA and IgM) (p<.05). This study indicated multiple beneficial effects of the inclusion of B. papyrifera (60% of the roughage feed) on the growth performance, carcase traits, meat quality and immune response in Hu rams. It could be used as a high-quality unconventional feedstuff for rams. HIGHLIGHTS The addition of Broussonetia papyrifera to the diet resulted in a significant improvement in the average weight gain (AWG) and average daily gain (ADG) of Hu rams. Adding appropriate proportion of B. papyrifera in diets positively modulates fatty acid percentage in the longissimus dorsi muscle, and also increases immunoglobulins (IgG, IgA and IgM) in blood. Broussonetia papyrifera could be used as a high-quality unconventional feedstuff for rams and has a positive effect on their growth performance, meat quality and immune performance.