In the past, the use of silage-based diets for finishing lambs indoors has met with limited success. Good quality silage is required to maximize voluntary intake but liveweight gains on silage alone are still generally low (Reed, 1979). While cereal supplements have been shown to improve lamb performance at the expense of silage intake, additional protein may have a stimulatory effect on both (Yilala and Bryant, 1985). This trial was therefore designed to investigate the performance responses of silage-fed hill lambs to increasing levels of whole barley and fishmeal supplementation and to examine the effect of a store period on these responses.

Two hundred and forty Scottish Blackface wether lambs, 5 months of age with a liveweight of 26.5 ± 0.18 kg (mean ± s.e.), which had all been reared as singles, were selected for the trial. On housing in September all lambs were kept under artificial lighting conditions of 14th light : 10h dark to remove the confounding effect of daylength.