妊娠后期母羊饲粮营养水平对产后羔羊生长性能、器官发育和血清抗氧旨标的影响

本试验在干物质采食量一致条件下,改变精料补充料与饲草比例调控妊娠后期母羊饲粮营养水平,旨在研究其对产后羔羊生长性能、器官发育和血清抗氧化指标的影响.选用健康、年龄[(11.0±1.0)月龄]和体重[(44.43±2.20) kg]相近、妊娠90 d的怀双羔初产湖羊母羊66只,分为3组,每组22只.以干物质为基础按照精料补充料与饲草比例分别为5∶5(5∶5组)、4∶6(4∶6组)和3∶7(3∶7组)饲喂至产羔,产羔后各组母羊饲喂相同的全混合日粮,自由采食.出生10、60 d屠宰羔羊测定各组织器官重量,出生20、60 d采集羔羊血清测定血清抗氧化指标.结果表明:1)妊娠后期母羊饲粮营养水平对羔羊初生重、哺乳期(出生0～60 d)羔羊体重均无显著影响(P>0.05),但随营养水平降低,羔羊初生重有降低趋势(0.05≤P<0.10),出生40和50 d体重有增加趋势(0.05≤P<0.10).2)出生0d,随着妊娠后期母羊饲粮营养水平的降低,羔羊的胸深极显著提高(P<0.01),体斜长显著降低(P<0.05);出生60 d,随着妊娠后期母羊饲粮营养水平的降低,羔羊的胸深、曲冠臀长显著或极显著提高(P<0.05或P<0.01).3)出生10 d,羔羊的肝脏、肺脏的重量随妊娠后期母羊饲粮营养水平的降低而显著降低(P<0.05);出生60 d,各组羔羊的组织器官重量差异不显著(P>0.05).4)出生20和60 d,随着妊娠后期母羊饲粮营养水平的降低,羔羊血清中总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化酶(GSH-Px)含量显著或极显著提高(P<0.05或P<0.01),丙二醛(MDA)含量极显著降低(P<0.01).妊娠后期通过精料补充料与饲草比例调控母羊饲粮营养水平时发现,低营养水平(低精料补充料比例)能够降低羔羊初生重,但经补偿生长作用,羔羊血清抗氧化能力得到提高,生长性能也得到恢复.

Effects of Maternal Dietary Nutrient Level in Late Gestation on Growth Performance,Organ Development and Serum Antioxidant Capacity of Postpartum Lambs

Under the same dry matter intake condition, concentrate supplement to forage grass ratio was changed to change dietary nutrient level of ewes in late gestation, this study aimed to investigate the effects on growth performance, organ development and serum antioxidant capacity of postpartum lambs.Sixty-six healthy primiparous Hu ewes at 90 days of gestation with similar age [(11.0±1.0) months of age] and body weight[(44.43±2.20) kg] were randomly divided into 3 groups with 22 ewes per group.Concentrate supplement and forage grass were offered to ewes at ratios of 5∶5 (5∶5 group), 4∶6 (4∶6 group) and 3∶7 (3∶7 group) until parturition.After parturition, ewes were fed the same total mixed ration ad libitum.Lambs were slaughtered to determine tissue and organ weight at 10 and 60 days after birth, and serum antioxidant indexes were determined at 20 and 60 days after birth.The results showed as follows : 1) there were no significant effects of maternal dietary nutrient level in late gestation on birth weight and body weight at suckling period (0 to 60 days after birth) (P>0.05), but with the nutrient level decreased, lamb birth weight had a decreased trend (0.05 ≤P<0.10) and body weight at 40 and 50 days after birth had an increased trend (0.05≤P<0.10).2) At 0 day after birth, with the decrease of dietary nutrient level of ewes in late gestation, chest depth of lambs was significantly increased (P<0.01), while body length was significantly decreased (P<0.05);at 60 days after birth,with the decrease of dietary nutrient level of ewes in late gestation, chest depth and curved crown-rump length of lambs were significantly increased (P<0.05 or P<0.01).3) At 10 days after birth, with the decrease of dietary nutrient level of ewes in late gestation, lung and liver weights of lambs were significantly decreased (P<0.05);at 60 days after birth, there was no significant difference on organ weight (P>0.05).4) At 40 and 60days after birth, with the decrease of dietary nutrient level of ewes in late gestation, serum total antioxidant capacity, superoxide dismutase activity and glutathione peroxidase content of lambs were significantly increased(P<0.05 or P<0.01), and serum malondialdehyde content was significantly decreased (P<0.05).In late gestation, when regulating dietary nutrient level by changing concentrate supplement to forage grass ratio, it is observed that low nutrient level (lower concentrate supplement ratio) had the tendency of decreasing birth weight of lambs, but after nutrient compensate, serum antioxidant capacity of lambs is improved, and growth performance recovers.[Chinese Journal of Animal Nutrition, 2017, 29 (2) : 636-644]