The Effects upon the intake and performance of store lambs of supplementing grass silage with barley, fish meal and rapeseed meal

Abstract

ABSTRACTTwo experiments are described in which individually-penned Suffolk × (Blue-faced Leicester × Swaledale) lambs were given complete diets based on grass silage, and voluntary intake, live-weight gain and nitrogen (N) retention were measured.Experiment 1 investigated the effects of supplements of fish meal (0, 60 and 120 g/kg diet dry matter (DM)) and barley (0, 150 and 300 g/kg diet DM) in a 3 × 3 design using 72 lambs. The lambs averaged 35 kg live weight at the start of the 47-day experiment. Fish-meal supplements increased daily intakes of diet DM, silage DM and metabolizable energy (ME), and improved daily gains, carcass weights and N retention. Barley supplements increased daily intakes of diet DM and ME, but reduced silage DM intake; live-weight gain, carcass weight and N retention were all improved.Experiment 2 investigated the effects of supplements of rapeseed meal (0 and 120 g/kg diet DM) in two forms (untreated and formaldehyde-treated) and barley (0 and 150 g/kg diet DM) in a 2 × 2 × 2 design with two missing treatments and using 48 lambs. The lambs averaged 39 kg live weight at the start of the 42-day experiment. Rapeseed meal supplements increased daily intakes of diet DM, silage DM and ME, and improved daily gains, carcass weights and N retention. Form of rapeseed meal had no effect. Barley increased diet DM and ME intakes and improved daily gains and carcass weights.