The effect of weight at mating and of nutrition during mid-pregnancy on the birth weight of lambs from primiparous ewes

摘要: Forty-eight approximately 18-month-old Scottish Blackface ewes were used to study the effects of two levels nutrition during mid-pregnancy (30–98 days gestation) on birth weight lambs from varying in weight, size and condition at first mating. The mean live (42–4 kg), index (31–9) score (2–4) mating 26 flock A all less than those 22 B (54–5, 39–4 2–9 respectively). Mean intakes low high nutritional treatment 10–6 22–0 g/kg/day respectively a pelleted diet supplying 8–81 MJ metabolizable energy 125–5 g crude protein/kg. These produced estimated changes net maternal – 5 0 kg respectively.Mean lamb weights treatments were:flock A, 3–32 3–83 kg; B, 4–96 4–23 respectively. Analyses showed intake have positive effect ewes, negative ewes. Mating accounted for 78% variance but had little higher level feeding.The practical implications results are discussed relation juvenile nutrition.