营养限制与补偿对蒙古羔羊体重和血液中生长相关激素的影响

试验研究不同能氮水平的营养限制与补偿对蒙古羔羊体重和血液生长相关的激素影响。选用内蒙古草原上健康的、平均体重15 kg左右的蒙古羔羊64只,随机分为对照组(CG)、限制1组(RG1)和限制2组(RG2)三个组,营养限制期(60 d)分别饲喂ME 10.88 MJ/kg、CP 13.0%(CG),ME10.88 MJ/kg、CP 8.9%(RG1),ME 8.62 MJ/kg、CP 5.7%(RG2)三个营养水平的日粮;营养补偿期(90 d)各组饲喂同一能氮水平饲粮(ME 9.75 MJ/kg,CP 12%)。结果表明:①随着营养水平的逐步降低,在限制末期,RG1组和RG2组羔羊的平均体重显著低于CG组(P<0.05),在补偿期,RG2组平均日增重显著高于CG组(P<0.05)。②在限制末期RG2组血液中GHRH及RG1、RG2组血液中GH浓度显著高于CG组(P<0.05),而RG2组血液中SS、IGF-I浓度显著低于CG组(P<0.05)。在补偿期,RG1、RG2组血液中IGF-I浓度有升高的趋势(P>0.05)。结果提示,营养限制所导致的羔羊血液中GHRH浓度升高和SS浓度降低可能是其在限制期血液中GH浓度升高及其在补偿期快速生长的原因之一。

Effect of nutrient restriction and compensation on body weight and hormones in blood of Mongolia lambs

This experiment was conducted to study the effect of different nutrient restriction and compensation on body weight and hormones in blood of Mongolia lambs.Sixty-four healthy Mongolia lambs with average bodyweight of 15 kg were randomly allotted to control group(CG),restricted group1(RG1) and restricted group 2(RG2),respectively.The diet nutritional levels of the 3 groups were ME 10.88 MJ/kg,CP 13.0%(CG)、 ME 10.88 MJ/kg,CP 8.9%(RG1)、ME 8.62 MJ/kg,CP5.7%(RG2) in nutrition restriction period.The 3 groups were fed with the same diet(ME: 9.75 MJ/kg,CP: 12%) in nutrition compensation period.The results showed that: ① with the supply of nutrition decreasing at the end of restriction period,the lambs’ body weight in RG1 and RG2 were significantly lower than those of CG(P<0.05),the ADG of RG2 was significantly higher than that of CG in the compensation growth period(P<0.05).② The GHRH concentrations in RG2 and the GH concentrations of lambs in RG1 and RG2 were enhanced(P<0.05),but the SS、IGF-I concentrations in RG2 were significantly lower than those of CG(P<0.05) in restriction period.During recoupment period,the concentrations of GHRH、IGF-I in RG1 and RG2 increased(P>0.05).These results indicated that enhanced growth rates of lambs in RG1 and RG2 at the compensatory growth were associated with the higher GHRH concentrations and the lower SS concentrations caused by nutrient restricted.