不同剩余采食量对德新肉用细毛羊生长性能、血清生化指标、肝脏及十二指肠黏膜抗氧化能力的影响

Effects of Different Residual Feed Intake on Growth Performance,Serum Biochemical Indexes,and Antioxidant Indexes in Live and Duodenal Mucosa of Dexin Meat⁃Type Fine Wool Sheep

本试验旨在研究高、中、低剩余采食量(RFI)对新疆德新肉用细毛羊生长性能、血清生化指标、肝脏和十二指肠黏膜抗氧化指标的影响。选用50只70日龄德新肉用细毛羊公羔作为试验群体,单栏饲喂114 d,其中预试期14 d,正试期100 d。根据线性回归方程筛选出RFI区间最小值和最大值分别为-0.31和+0.10 kg/d,并按照RFI>平均值+0.5标准差(SD)、平均值+0.5SD≥RFI≥平均值-0.5SD和RFI<平均值-0.5SD分为高RFI组(H-RFI组,11只)、中RFI组(M-RFI组,18只)和低RFI组(L-RFI组,13只)。试验期每20 d测定平均日增重及平均日采食量;试验期第100天,羊只屠宰后称量内脏重,测量消化道长度,并对血清中甲状腺激素、促甲状腺激素、瘦素、生长激素及肝脏和十二指肠黏膜抗氧化指标进行测定。结果表明:1)H-RFI组平均日采食量和RFI极显著高于L-RFI组和M-RFI组(P<0.01),料重比极显著高于L-RFI组和M-RFI组(P=0.01)。各组间羊只平均日增重、中期代谢体重无显著差异(P>0.05)。2)L-RFI组心脏重、脾脏重、肾脏重显著高于H-RFI组(P<0.05),头重、蹄重、肺脏重、肝脏重极显著高于H-RFI组(P≤0.01)。M-RFI组空肠重显著高于H-RFI组(P<0.05)。3)L-RFI组血清生长激素含量显著低于H-RFI组(P=0.05),血清甲状腺激素和瘦素含量极显著低于M-RFI组和H-RFI组(P<0.01)。4)肝脏抗氧化指标中,L-RFI组总蛋白(TP)含量极显著低于M-RFI组和H-RFI组(P<0.01),丙二醛(MDA)含量显著高于M-RFI组(P<0.05),谷胱甘肽过氧化物酶(GSH-Px)活性和总抗氧化能力(T-AOC)显著高于H-RFI组(P<0.05),L-RFI组和M-RFI组过氧化物歧化酶(SOD)活性显著高于H-RFI组(P=0.05)。十二指肠黏膜抗氧化指标中,M-RFI组TP含量极显著高于L-RFI组和H-RFI组(P=0.01),L-RFI组GSH-Px活性显著低于M-RFI组(P<0.05),M-RFI组过氧化氢酶(CAT)活性显著高于H-RFI组(P<0.05),M-RFI组T-AOC显著高于L-RFI组和H-RFI组(P<0.05)。由此可见,选择L-RFI的德新公羔可以有效减少饲粮消耗,并对羊只生长性能无显著影响,对德新肉用细毛羊选种选育具有较好的提升效果。

The aim of this experiment was to investigate the effects of high,medium and low residual feed in-take(RFI)on growth performance,serum biochemical indexes and antioxidant indexes of liver and duodenal mucosa of Dexin meat-type fine wool sheep.Fifty 70-day-old Dexin fine wool male lambs were selected as the experimental group and fed in a single column for 114 days,including 14 days in the pre-trial period and 100 days in the experimental period.According to the linear regression equation,the minimum and maximum values of the RFI interval were screened out to be-0.31 and+0.10 kg/d,respectively,and were divided into high RFI group(H-RFI group)according to RFI>mean+0.5 standard deviation(SD),mean+0.5SD≥RFI≥mean-0.5SD and RFI<mean-0.5SD,respectively.11 sheep),medium RFI group(M-RFI group,18 sheep)and low RFI group(L-RFI group,13 sheep).The average daily gain and average daily feed intake were meas-ured every 20 days during the experiment.On the 100th day of the experiment period,the visceral weight of the sheep was weighed,the length of digestive tract was measured,and the serum contents of thyroid hor-mone,thyrotropin,leptin,growth hormone and antioxidant indexes of liver and duodenal mucosa were meas-ured.The results showed as follows:1)the average daily feed intake and RFI in H-RFI group were significant-ly higher than those in L-RFI and M-RFI groups(P<0.01),and the ratio of feed to gain in H-RFI group was significantly higher than that in L-RFI and M-RFI groups(P=0.01).There were no significant differences in average daily gain and medium-term metabolic weight among all groups(P>0.05).2)In the L-RFI group,the heart weight,spleen weight and kidney weight were significantly higher than those in the H-RFI group(P<0.05),and the head weight,hoof weight,lung weight and liver weight was significantly higher than that in the H-RFI group(P≤0.01).The duodenal weight in the M-RFI group was significantly higher than that in the H-RFI group(P<0.05).3)The serum growth hormone content in L-RFI group was significantly lower than that in H-RFI group(P=0.05),and the serum thyroid hormone and leptin contents in L-RFI group were sig-nificantly lower than those in M-RFI group and H-RFI group(P<0.01).4)Among the liver antioxidant inde-xes,the total protein(TP)content in L-RFI group was significantly lower than that in M-RFI group and H-RFI group(P<0.01),and the malondialdehyde(MDA)content in L-RFI group was significantly higher than that in M-RFI group(P<0.05).The glutathione peroxidase(GSH-Px)activity and total antioxidant capacity(T-AOC)in L-RFI group were significantly higher than those in H-RFI group(P<0.05),and the peroxidase dismutase(SOD)activity in L-RFI and M-RFI groups was significantly higher than that in H-RFI group(P=0.05).Among the antioxidant indexes of duodenal mucosa,TP content in M-RFI group was significantly high-er than that in L-RFI group and H-RFI group(P=0.01),GSH-Px activity in L-RFI group was significantly lower than that in M-RFI group(P<0.05),and catalase(CAT)activity in M-RFI group was significantly higher than that in H-RFI group(P<0.05).T-AOC in M-RFI group was significantly higher than that in L-RFI group and H-RFI group(P<0.05).In conclusion,the selection of L-RFI can effectively reduce the dietary consumption of Dexin male lamb,and has no significant effect on the growth performance of sheep,and has a better effect on breeding selection and breeding of Dexin meat-type fine wool sheep for meat.