颈静脉灌注精氨酸对奶牛血液生化指标及必需氨基酸含量的影响

试验旨在研究颈静脉灌注精氨酸(Arg)对奶牛血常规指标、血清生化指标及必需氨基酸含量的影响。选用6头体重、胎次、泌乳期、泌乳量和体况等基本一致的荷斯坦奶牛,采用3×3复拉丁方设计,随机分为3组,即对照组(灌注酪蛋白模式的氨基酸混合物)、Arg灌注组(灌注37.66 g/d)和等氮丙氨酸组(灌注77.24 g/d),进行7 d灌注期+15 d间隔期的颈静脉灌注试验。结果表明:与对照组和等氮丙氨酸组相比,Arg灌注组可降低白细胞计数(P<0.01),而对其他血常规指标无显著影响;等氮丙氨酸组高密度脂蛋白水平高于对照组(P<0.05);低密度脂蛋白以Arg灌注组最高,但3组间差异不显著;与对照组和等氮丙氨酸组相比,Arg灌注组血浆中Arg含量提高(P<0.05),但其他8种必需氨基酸和总必需氨基酸含量未见显著差异。由此可见,颈静脉灌注Arg对泌乳奶牛脂质代谢有一定的调控作用,对血常规指标和必需氨基酸含量的影响不大。

Effects of Arginine Jugular Infusion on Blood Biochemical Indices and Essential Amino Acid Concentration of Lactating Cows

This experiment was conducted to determine the effects of jugular infusion of arginine(Arg) on blood routine examination, serum biochemical indices and concentration of essential amino acids(EAA) of dairy cows at mid-lactation. Six healthy lactating cows at similar lactation stages with similar body weight, body condition, milk yield and parties were used in a 3 × 3 Latin square trail. Cows were randomly divided into three groups, which were control group(AA mixture at casein profile), Arg group(infused 37.66 g/d) and alanine group(equal nitrogen to Arg group, infused 77.24 g/d). Each trail period lasted for 22 days containing a 7-day infusion period and a 15-day interval period. Blood was collected before morning feeding at the last day of infusion period to detect blood biochemical indices and EAA concentration. The results showed that Arg infusion significantly inhibited the white blood cell count(WBC) relative to the other two groups(P<0.01), but no influence on the remaining blood routine examination indices was detected(P>0.05). High density lipoprotein cholesterol(HDL-C) in alanine group was significantly greater than that in the control(P<0.05), but low density lipoprotein(LDL-C) was not significantly different among three treatments(P>0.05). Compared with the control or alanine group, infusion of Arg significantly increased Arg concentration in plasma, while there were no significant differences for the remaining AA and total EAA(P>0.05). In conclusion, jugular infusion of Arg had a certain regulation on lipid metabolism. However, there was no significant impact on blood routine indexes and total EAA concentration in lactating dairy cows.