Teagasc, Grassland Science Department, Animal & Grassland Research & Innovation Centre, Mellows Campus, Athenry, Co. Galway H65R718, Ireland.
School of Veterinary Medicine, University College Dublin, Dublin D04 V1W8, Ireland.
Animal. 2021 Jan;15(1):100068. doi: 10.1016/j.animal.2020.100068. Epub 2020 Dec 10.
In many countries, daily herbage accumulation on pasture declines towards zero during the winter period; thus, many pregnant ewes are housed and offered conserved forages supplemented with concentrate prior to parturition. The effects of forage type and feed value (FV), offering soybean meal with maize silage during mid and late pregnancy, and concentrate feed level in late pregnancy on the performance of ewes and their progeny (to slaughter) were evaluated. Ewes (n = 151) were assigned to one of nine treatments from mid-pregnancy until lambing. Medium FV and high FV grass silages (metabolisable energy concentrations of 10.7 and 12.0 MJ/kg DM) were offered ad libitum supplemented with either 15 or 25 kg concentrate/ewe during late pregnancy. Low and high DM maize silages (starch concentrations of 80 and 315 g/kg DM) were offered ad libitum either alone or with soybean meal (200 g/d) and supplemented with 15 kg concentrate during late pregnancy. A final treatment consisted of high FV grass silage supplemented with 5 kg soybean/ewe over the final 4 weeks of pregnancy. Ewes and lambs were put to pasture in a rotational-grazing system within 3 days of lambing. There were no interactions (P > 0.05) between grass silage FV and concentrate feed level for ewe or lamb traits. Increasing grass silage FV increased food intake (P < 0.001) during late pregnancy, ewe BW and body condition score (BCS) at lambing (P < 0.001), lamb BW at birth (P < 0.001) and weaning (P < 0.05), and reduced age at slaughter (P = 0.06). Increasing concentrate feed level increased metabolisable energy (P < 0.05) intake during late pregnancy but had no effect (P > 0.05) on ewe or lamb performance. Increasing maize DM at harvest and offering soybean meal with maize silage increased food intake (P < 0.001) and ewe BW and BCS at lambing (P < 0.05 or P < 0.01). Offering soybean meal with maize silage increased lamb BW at birth (P < 0.01) and reduced age at slaughter (P < 0.05). Reducing supplementation of high FV grass silage to 5 kg of soybean meal had no effect (P > 0.05) on animal performance. Replacing grass silage with maize silage did not affect (P > 0.05) BW gain of lambs. It is concluded that increasing the FV of the grass silage offered during pregnancy had the greatest positive impact on ewe and lamb performance.
在许多国家，冬季期间牧场的日草料积累趋于零；因此，许多怀孕的母羊在分娩前被圈养，并提供保存的草料，并补充浓缩饲料。本研究评估了在妊娠中期和后期提供豆粕与玉米青贮饲料以及妊娠后期浓缩饲料水平对母羊及其后代（屠宰）性能的影响。从妊娠中期到分娩，将 151 只母羊分配到 9 种处理中的一种。中等和高 FV 的草青贮料（可代谢能浓度分别为 10.7 和 12.0MJ/kg DM）自由采食，妊娠后期分别补充 15 或 25kg 浓缩饲料/只。低和高 DM 玉米青贮料（淀粉浓度分别为 80 和 315g/kg DM）自由采食，或单独或与豆粕（200g/d）一起提供，并在妊娠后期补充 15kg 浓缩饲料。最后一种处理是在妊娠的最后 4 周内，每天补充 5kg 豆粕/只的高 FV 草青贮料。分娩后 3 天内，母羊和羔羊被放到轮牧系统的牧场上。草青贮料 FV 和浓缩饲料水平对母羊或羔羊性状没有相互作用（P > 0.05）。增加草青贮料 FV 增加了妊娠后期的采食量（P < 0.001），增加了母羊的 BW 和体况评分（BCS）（P < 0.001），羔羊的 BW 出生时（P < 0.001）和断奶时（P < 0.05），并减少了屠宰年龄（P = 0.06）。增加浓缩饲料水平增加了妊娠后期的可代谢能（P < 0.05）采食量，但对母羊或羔羊的性能没有影响（P > 0.05）。增加收获时的玉米 DM 并与玉米青贮料一起提供豆粕增加了采食量（P < 0.001）和母羊的 BW 和 BCS 分娩时（P < 0.05 或 P < 0.01）。与玉米青贮料一起提供豆粕增加了羔羊的 BW 出生时（P < 0.01），并减少了屠宰年龄（P < 0.05）。将高 FV 草青贮料的补充减少到 5kg 豆粕对动物性能没有影响（P > 0.05）。用玉米青贮料代替草青贮料不会影响羔羊的 BW 增重（P > 0.05）。研究结果表明，在妊娠期间增加草青贮料的 FV 对母羊和羔羊的性能有最大的积极影响。
