奶牛静脉血内毒素浓度及其与产奶量的相关性

Endotoxin Concentration in Venous Blood and Its Correlation with Milk Yield of Dairy Cows

为调查我国当前主流饲喂方式下奶牛静脉血内毒素浓度的范围及内毒素浓度与产奶量的相关性,本试验首先验证了应用鲎试剂法定量奶牛静脉血中内毒素浓度的可行性,在此基础上,分别检测了安徽牧场1(60头,饲粮精粗比45∶55)、江苏牧场(15头,按产奶量高低精粗比分别为20∶80、45∶55、50∶50)和安徽牧场2(14头,饲粮精粗比70∶30)共89头奶牛的尾静脉血中内毒素浓度,并进行了内毒素浓度与产奶量的相关性分析。结果表明:鲎试剂法可有效检测奶牛静脉血中内毒素浓度,3个牧场奶牛静脉血中内毒素浓度高低不等,在0～1.50 EU/mL范围内。奶牛静脉血中内毒素浓度与产奶量之间的相关性皆不显著(P>0.05),但安徽牧场2的相关系数(0.195 2)大于安徽牧场1(0.020 5)和江苏牧场(0.037 6)。结果提示,鲎试剂法可用于定量检测奶牛血中内毒素浓度,在我国当前的饲喂方式下,奶牛血液中普遍含有内毒素,静脉血内毒素浓度与产奶量无显著相关性。

In order to investigate the range of endotoxin concentration in venous blood of dairy cows and the correlation between endotoxin concentration and milk yield under main feeding modes at present in China,the feasibility of quantification of endotoxin concentration using the method of limulus amebocyte lysate chromogenic endotoxin was validated,and endotoxin concentration in venous blood of 89 dairy cows from three dairy farms was analyzed.They were farm 1 in Anhui province [60 cows;ratio of concentration to forage(C∶ F) was 45∶ 55],a farm in Jiangsu province(15 cows;ratios of concentration to forage were 20∶ 80,45∶ 55 and 50∶ 50,respectively,and those were set according to milk yield),and farm 2 in Anhui province(14 cows;ratio of concentration to forage was 70∶ 30).Correlation between endotoxin concentration and milk yield was also analyzed.The results showed as follows: the limulus amebocyte lysate chromogenic endotoxin assay can be used for quantification of endotoxin concentration in venous blood of dairy cows,and endotoxin concentration of cows ranged from 0 to 1.50 EU/mL.The correlation between endotoxin concentration and milk yield was not significant(P>0.05),while correlation coefficient of dairy cows in Anhui farm 2(0.129 3) was higher than that of dairy cows in Anhui farm 1(0.020 5) and Jiangsu farm(0.037 6).The results indicate that limulus amebocyte lysate chromogenic endotoxin assay can be used for quantification of endotoxin concentration in blood of dairy cows;under main feeding modes at present in China,different concentrations of endotoxin are observed in blood of dairy cows,and there is no correlation between endotoxin concentration and milk yield.