中国荷斯坦牛步态评分及其对生产性能和血常规指标的影响

Locomotion Score and Its Impacts on Production Performance and Blood Routine Indexes in Chinese Holstein

为探究荷斯坦牛步态评分(locomotion score,LS)影响因素及其对生产性能和血常规指标的影响,本研究收集测定了北京地区2个规模化牧场1486头泌乳牛的体况评分(body condition score,BCS)、LS和DHI(dairy herd improvement)数据,并测定了101头泌乳牛的血常规指标。采用固定模型分析了牧场、胎次和泌乳阶段对LS的影响,以及LS和BCS等因素对日产奶量、体细胞评分、乳成分和血常规指标的影响。结果表明,试验牛的胎次和泌乳阶段均对LS有极显著影响,LS随胎次的升高而增加,从1胎至5胎及以上,LS升高了0.71分;泌乳阶段Ⅲ(100~199 d)、Ⅵ(350 d以后)的LS均显著高于阶段Ⅱ(45~99 d)(P<0.05),且均高于2分。LS对日产奶量、乳成分和体细胞评分均无显著影响(P>0.05),但LS≥4分的奶牛日产奶量最低,较LS=1分的奶牛日产奶量降低了2.29 kg。各项血常规指标中,LS对奶牛红细胞数、血红蛋白含量、红细胞平均血红蛋白浓度、淋巴细胞数均有显著影响(P<0.05),而对白细胞数无显著影响(P>0.05)。随LS升高,奶牛红细胞数、淋巴细胞数、血红蛋白含量和红细胞平均血红蛋白浓度均表现出不同程度的降低。LS较差的奶牛,其机体的免疫力和造血功能会受到不同程度的影响。在规模化牧场中,定期评估牛群的LS能及时发现牛群肢蹄管理的问题,对减少因肢蹄问题引起的生产性能损失和过早淘汰等具有重要意义。

To investigate the influencing factors of locomotion score(LS)and its impacts on production performance and blood routine index in Holstein,body condition score(BCS),LS and DHI(dairy herd improvement)of 1486 lactating cows from two dairy farms,and the blood routine indexes of 101 lactating cows from one farm in Beijing were measured.The fixed model was used to analyze the impacts of herd,parity and lactation stage on LS,and the impacts of LS and BCS on daily milk yield,somatic cell score,milk composition and blood routine indexes in dairy cows.The results showed that both parity and lactation stage had significant impacts on LS.The LS increased with the increase of parit,the LS increased by 0.71 from first lactation to fifth and above lactation.The LS of cow in lactation stageⅢ(100-199 d)andⅥ(after 350 d)were significantly higher than cow in stageⅡ(45-99 d)(P<0.05),and both were higher than 2.The LS had no significant impacts on daily milk yield,milk composition and somatic cell score(P>0.05).However,the milk yield of the cow with LS≥4 was the lowest,and a decrease of 2.29 kg was found compared with the cow with LS=1.Among the various blood routine indexes,LS had significant impacts on red blood cell count,hemoglobin content,mean corpuscular hemoglobin concentration and lymphocyte count(P<0.05),and had no significant impacts on white blood cell count(P>0.05).With the increase of LS,the red blood cell count,hemoglobin content,mean corpuscular hemoglobin concentration and lymphocyte count of cows decreased with different extents.There were some problems on the body immunity and hematopoiesis of cows with poor LS.In dairy farm,regular evaluation of LS could be used to find the management problems of feet and legs,which had a great significance to reduce the loss of production performance and early culling caused by hoof disease.