Does offering concentrate supplement during late pregnancy affect twin- and triplet-bearing ewe and lamb performance?

This study investigated the effect of offering concentrate supplement during late pregnancy on twin- and triplet-bearing ewe and lamb performance. Twin- (n=40) and triplet-bearing (n=20) ewes were grazed on a 6 cm herbage height from day 70 of pregnancy until parturition. From pregnancy day 102, half of the ewes from each litter size were offered 400 g/ewe per day of concentrate sheep pellets. From day 102 until day 145 of pregnancy, ewes offered concentrate gained 60 g more liveweight per day than ewes offered pasture only (P0.01). Ewes offered concentrate were also under less metabolic stress in late pregnancy, as indicated by lower (P0.05) plasma beta-hydroxybutyrate (BOH) and non-esterified fatty acid (NEFA) concentrations. Offering concentrate increased lamb birth weight from 3.9 to 4.2 kg (P0.05) and tended to increase lamb plasma gamma-glutamyl-transferase (GGT) concentrations at age 24-36 h (P = 0.08). It had no effect, however, on lamb plasma glucose or immuno-globulin G (IgG) concentrations within 24-36 h of age, lamb growth from birth until day 52 of lactation or lamb survival. Ewes offered concentrate reared a greater total weight of lamb to day 52 of lactation than ewes offered pasture only. The economic viability of offering a concentrate to these ewes grazing a 6 cm sward could not be established.