补喂L-精氨酸对返情纯血母马妊娠率及血浆参数的影响

【目的】试验旨在研究补喂L-精氨酸对返情纯血马妊娠率及血液参数的影响。【方法】选择返情纯血母马14匹随机分为2组，每组7匹（n=7），分别为对照组、L-精氨酸组，对照组饲喂基础饲粮，L-精氨酸组在基础饲粮中添加50 g/d L-精氨酸；预饲期7 d，试验期30 d。返情母马发情时，第一次人工输精结束当天补喂L-精氨酸；配种结束时直肠B超检查妊娠情况，统计妊娠率，分别于试验第0、15、30天颈静脉采血，用于测定总一氧化氮合成酶（total nitric oxide synthetase，TNOS）、内皮型一氧化氮合成酶（endothelial nitric oxide synthetase，eNOS）活性及一氧化氮（nitric oxide，NO）、血管内皮生长因子（vascular endothelial growth factor，VEGF）、生长激素（growth hormone，GH）、胰岛素样生长因子（insulinlike growth factor，IGF）含量等指标。【结果】与对照组相比，L-精氨酸组妊娠率显著提高（P<0.05）；试验第0、15、30天血浆TNOS、eNOS、鸟氨酸脱羧酶（orinithine decarboxylase，ODC）活性及NO、IGF-Ⅰ、IGF-Ⅱ、VEGF含量在两组间均无显著差异（P>0.05）；试验第30天L-精氨酸组血浆氨（ammonia，NH₃）、尿素氮（urea nitrogen，UN）含量分别比对照组降低13.49%、26.91%（P<0.05）。与对照组相比，试验第30天L-精氨酸组血浆GH含量提高50.26%（P<0.01），试验第0、15、30天两组间母马血浆免疫球蛋白A （IgA）、免疫球蛋白M （IgM）、免疫球蛋白G （IgG）含量均无显著差异（P>0.05）。【结论】返情纯血母马补喂L-精氨酸能显著提高妊娠率，改变母马体循环血浆UN、NH₃、GH含量。L-精氨酸可作为营养调控剂提高纯血母马妊娠率。

Effect of Supplementation with L-arginine on Pregnancy Rate and Plasma Parameters of Re-service Thoroughbred Horses

【Objective】 The purpose of the experiment was to study the effect of supplementation with L-arginine on pregnancy rate and plasma parameters of re-service thoroughbred horses.【Method】 14 re-service thoroughbred horses were randomly divided into 2 groups, 7 in each group(n=7), as the control group and L-arginine group.The control group was fed with basic diet, and the L-arginine group was added with 50 g/d L-arginine on the basis of basic diet.The pre feeding period was 7 d, and the trial period was 30 d.When the returning mare was in estrus, L-arginine was supplemented on the day after the first artificial insemination.At the end of mating, the pregnancy was examined by rectum B-ultrasound, and the pregnancy rate was calculated.Blood was collected from the jugular vein of mares at 0, 15 and 30 d respectively.The activities of total nitric oxide synthase (TNOS), endothelial nitric oxide synthase (eNOS) and the contonts of nitric oxide (NO), vascular endothelial growth factor (VEGF), growth hormone (GH), insulin-like growth factor(IGF) were measured.【Result】 Compared with the control group, the pregnancy rate of the L-arginine group was significantly increased (P<0.05).There was no significant difference in plasma TNOS, eNOS, NO, ODC, IGF-Ⅰ, IGF-Ⅱ and VEGF levels/activities between the two groups at 0, 15 and 30 d (P>0.05).On the 30th day of the test, the plasma ammonia (NH₃) and urea nitrogen (UN) contents in the L-arginine group decreased by 13.49% and 26.91% respectively compared with the control group (P<0.05).Compared with the control group, the plasma GH content on the 30th day of the test was significantly increased by 50.26% in L-arginine group (P<0.01).And there was no significant difference in the contents of IgA, IgM and IgG of mares on the 0th, 15th, and 30th days of the test between two groups (P>0.05).【Conclusion】 Feeding L-arginine to the re-service thoroughbred horses could significantly increase the pregnancy rate and change the contents of UN, NH3 and GH in the circulating plasma of the mares.L-arginine could be used as a nutritional regulator to improve the pregnancy rate of thoroughbred mares.