营养限饲与补偿对蒙古羔羊体重、血清生化指标及胸脂脂肪因子基因表达的影响

Effect of Nutrient Restriction and Compensation on Weight,Serum Indexes and Gene Expression of Chest Fat Adipokines in Mongolian Lamb

试验旨在研究早期营养限饲与后期快速补偿对蒙古羔羊体重、血清生化指标及胸脂脂肪因子基因表达的影响。选用30只4月龄健康蒙古公羔羊,随机分为对照组(20.26kg±3.63kg)与限制组(21.29kg±3.00kg)。对照组羔羊自由采食,限制组羔羊维持水平饲养,限制期60d,限制饲养结束后立刻进入60d补偿期,补偿期两组饲喂相同日粮。于试验第30、60、90和120天从各组试验羊颈静脉采血,用试剂盒检测血清中甘油三酯(TG)、非酯化脂肪酸(NEFA)、总胆固醇(TC)浓度;并在限制和补偿末期屠宰羔羊,采集胸部脂肪组织,实时荧光定量PCR检测脂联素(Adiponectin)、内脂素(Visfatin)、过氧化物酶增殖物激活受体γ(PPAR-γ)、乙酰辅酶A羧化酶(ACC)基因表达量。结果表明:1限制期,限制组羔羊体重保持维持水平而对照组羔羊体重呈升高趋势;补偿期,限制组羔羊平均日增重显著高于对照组(P<0.05)。2限制期,限制组羔羊血清中TG浓度在第30和60天时显著低于对照组(P<0.05),而NEFA在第30天时显著高于对照组(P<0.05);补偿期,限制组TC浓度在第90天时显著低于对照组(P<0.05),而TG与NEFA两组间均无显著差异(P>0.05)。3限制期,限制组羔羊胸脂PPAR-γ和ACC基因表达量显著低于对照组(P<0.05),补偿期两组间无显著差异(P>0.05)。限制期和补偿期两组羔羊胸脂Adiponectin和Visfatin基因表达均无显著变化(P>0.05)。由此可知,营养限制时胸脂脂肪合成与脂肪细胞分化能力减弱,脂肪组织水解动员参与机体能量代谢,补偿时总胆固醇参与机体恢复生长。补偿期限制组羔羊快速增重,但ACC与PPAR-γ基因显著低于对照组。早期的生长限制与后期的补偿生长对羔羊胸脂Adiponectin与Visfatin无显著影响。

To study the effect of nutrient restriction and compensation on weight,serum indexes and gene expression of chest fat adipokine in Mongolian lamb,thirty male lambs were randomly divided into control group（20.26kg±3.63kg）and feed restricted group（21.29kg±3.00kg）.The experiment lasted for 120 days,including 60 days for feed restriction and 60 days for compensatory feed.At the end of each stage,five lambs from each group were slaughtered and chest fat was collected.Serum concentration of triglycerides,non-esterified fatty acids（NEFA）,total cholesterol were measured.Quantitative Real-time PCR were used to determine Adiponectin,Visfatin,PPAR-γand ACCgenes expression.The results showed that：①The lamb body weightof restricted group kept maintain level and that of control group showed a increase tendency.During the compensatory period,the average daily gain（ADG）of restricted group was significantly higher than control group（P〈0.05）.②During the restriction period,serum triglycerides concentration of lambs in restricted group was significantly decreased at day 30 and 60（P〈0.05）,and NEFA concentration was significantly increased at day 30（P〈0.05）.After 60 days of nutritional compensation,all serum parameters we tested were not significantly different between restrict group and control group（P〈0.05）.③During the restriction period,PPAR-γand ACCgene expression in restricted group were significantly lower than that of control group（P〈0.05）,while no significant differences were found during the compensation period（P〈0.05）.Adiponectinand Visfatin genes expression in chest fat was not significantly changed throughout the experiment（P〈0.05）.We could know that nutritional restriction reduced fatty acid synthesis and adipocyte differentiation ability,adipose tissue was mobilized energy metabolism,and total cholesterol was recoveried growth on the compensation.However,the ACCand PPAR-γgenes in restricted group were significantly decreased with the body weight increased rapidly during the compensatory stage.Adiponectin and Visfatin were not significantly different between restricted and compensatory stages.