Response of protein supplementation to Deccani lambs grazing on silvopastoral system during dry period.

摘要

This study was conducted to determine the effects of protein supplementation on the performance of lambs grazing on a silvopastoral system during the dry period. 18 Deccani lambs were divided into 3 groups and rotationally grazed for 75 days in the established silvopastoral system. Group I was allowed to graze solely on the silvopastoral system. Group II was also allowed to graze as in group I but were separated in the evening and fed with concentrate mixture at 1.5% of body weight. Group III was fed with Stylosanthes hamata forage on equi-nitrogen basis after grazing on silvopastoral system. Liveweight gain was significantly higher in animals supplemented with either stylo forage or concentrate mixture than in animals that grazed solely on silvopastoral system. The average daily gain (ADG) was significantly higher in groups II and III than in group I. Protein intake in the form of concentrate mixture/stylo forage synchronized with roughage intake and resulted to better nutrient availability for optimum rumen fermentation and microbial growth, which in turn improved the dry matter intake and nutrient digestibility in supplemented animals. Dry matter intake was significantly different among the groups. A similar trend was observed in dry matter and organic matter digestibility. A significantly higher digestibility of neutral detergent fibre and acid detergent fibre was observed in supplemented groups than in the control group. The retained nitrogen as percentage of intake (NPU) and absorbed nitrogen (BV) was significantly higher in supplemented groups. Lambs with protein supplementation had higher ADG and better feed efficiency, indicating that supplementation had beneficial effects on lambs grazing on a silvopastoral system during the dry season.