Effects of feeding different ensiled forages on the productivity and nutrient-use efficiency of finishing lambs

The effects of offering ensiled red clover (Trifolium pratense), lucerne (Medicago sativa), pea (Pisum sativum), kale (Brassica oleracea) and hybrid ryegrass (Lolium hybridicum) on the productivity and nutrient-use efficiency of lambs were investigated. Forages were cut, wilted for 24 h and ensiled as round bales. A hundred Suffolk-cross lambs, aged 8 months, were offered grass silage during a 5-week standardization period and then group-housed for 14 d and offered ad libitum access to a treatment silage. For the measurement period, lambs were split into four replicate groups of five lambs per treatment. Dry matter intake and live weight were recorded every 7 d over 56 d. The chemical composition of the silages differed for all the variables measured. Lambs offered pea silage had a very low liveweight gain and this treatment was discontinued after 21 d. Lambs offered the other forages had a higher liveweight gain than lambs offered ryegrass silage (P <0Æ001). Food conversion and nitrogen-use efficiency were higher in lambs offered the red clover, lucerne and kale silages compared with those offered ensiled ryegrass (P <0Æ001). These findings demonstrate the potential for using ensiled alternative forages rather than ryegrass to increase the productivity and nutrient use efficiency of livestock systems