单 位：
湖南农业大学动物科技学院;上海奶牛育种中心有限公司;上海光明荷斯坦牧业有限公司
关键词：
硒;围产期奶牛;生产性能;氧化应激;基因表达
摘 要：
为了给围产期奶牛硒添加量的确定提供更全面的理论基础和数据支持,试验选取140头中国荷斯坦奶牛按随机区组设计分为对照组、低剂量组、中剂量组和高剂量组,每组5个重复,每个重复7头奶牛。对照组奶牛饲喂基础日粮(硒含量为0.15 mg/kg DM),低剂量组、中剂量组和高剂量组奶牛在基础日粮中添加Na_2SeO_3至硒含量分别达0.3,0.45,0.6 mg/kg DM,预试期为5 d,正试期从预产前2周至产后4周,测定试验期间采食性能、泌乳性能和血液生化指标、肝脏抗氧化指标和关键基因表达。结果表明:各处理组之间奶牛的干物质摄入量(DMI)和体重变化无显著差异(P>0.05)。与对照组相比,中剂量组和高剂量组奶牛的泌乳量分别提高了1.7 kg/d和1.3 kg/d,但差异不显著(P>0.05);显著提高了乳蛋白产量(P<0.05);显著提高了围产期奶牛血液中总蛋白的浓度(P<0.05);显著降低了血液中谷草转氨酶(AST)和谷丙转氨酶(ALT)的活性(P<0.05);显著提高围产期奶牛血液、肝脏和奶中的硒水平(P<0.05),同时显著提高了围产期奶牛血液和肝脏的抗氧化能力(P<0.05);显著提高了肝脏中细胞型谷胱甘肽过氧化物酶(GPx1)mRNA的相对表达水平(P<0.05),但对磷脂氢谷胱甘肽过氧化物酶(GPx4)mRNA的相对表达水平无显著影响(P>0.05)。上述指标在中剂量组和高剂量组奶牛之间无显著差异(P>0.05)。结果说明围产期奶牛对硒的需求很高,含硒0.15 mg/kg DM的基础日粮无法满足奶牛的需求,此时奶牛的抗氧化能力低,日粮中补充硒达到0.45 mg/kg DM时,奶牛才有较强的抗氧化能力。
译 名：
The effects of dietary selenium supplementation on performance and oxidative stress status of transition dairy cows
作 者：
HAO Hongxiao;LIU Guanglei;ZHANG Peihua;College of Animal Science and Technology,Hunan Agricultural University;Shanghai Dairy Breeding Center Co.,Ltd;Shanghai Bright Holstan Co.,Ltd.;
关键词：
selenium;;transition dairy cows;;performance;;oxidative stress;;gene expression
摘 要：
In order to provide a theoretical basis and data support for the selenium additive amount in dairy cows during transition period. 140 health multiparous Holstein dairy cows were randomL y allocated to four treatments( 5 replicates in each group,and 7 cows in each replicate) in this study: Control( C),low dose group( LDG),middle dose group( MDG) and high dose group( HDG). Control group was fed with basal diets( containing Se 0. 15 mg/kg DM). LDG,MDG and HDG groups were supplemented with Na_2SeO_3in basal diets,and the content of selenium was 0. 3,0. 45 and 0. 6 mg/kg DM,respectively. The pre-trial period was 5 days. The formal period was from pre natal 2 weeks to postnatal4 weeks. Feeding performance,milking performance,blood biochemical parameters,and liver antioxidant index and gene expression were measured during experimental period. The results showed that there was no significant effect on the dry matter intake( DMI) and weight change among treatments( P > 0. 05). Compared with control,the milk yield of MDG and HDG were increased 1. 7 kg/d and 1. 3 kg/d respectively,but the results displayed no significant difference( P > 0. 05). MDG and HDG group had higher( P < 0. 05) of the milk protein yield and the total blood protein concentration( P < 0. 05). The levels of AST and ALT were decreased in the blood( P < 0. 05). In addition,compared with control,MDG and HDG group had higher( P < 0. 05) of the selenium levels in blood,liver and milk,and the antioxidant capacity of blood and liver were increased. The relative expression level of cytosolic glutathione peroxidase( GPx1) mRNA was increased( P < 0. 05),but had no significant effect on the relative expression level of phospholipid hydroperoxide glutathione peroxidase( GPx4) mRNA( P > 0. 05) in liver. There was no significant difference of the indexes between MDG and HDG. These results indicated that transition dairy cows were highly demanded for Se.Basal diet containing selenium 0. 15 mg/kg DM was not able to meet the needs of dairy cows. In that condition,the antioxidant capacity of cow was decrease as mentioned above. In the case of selenium supplement was 0. 45 mg/kg DM,the cows had sufficient antioxidant capacity.
