补喂来曲唑对速步马运动性能、血浆抗氧化指标与激素水平及体重的影响

Effects of Supplemental Feeding Letrozole on Athletic Performance,Plasma Antioxidant Indices and Hormone Levels,and Body Weight of Trotters

本试验旨在探究补喂来曲唑对速步马运动性能、血浆抗氧化指标与激素水及体重的影响。选取平均年龄为2.5岁、平均体重为(398.16±25.34)kg的经过良好速步训练的伊犁马公马10匹,随机分为2组,分别为对照组和试验组,每组5匹。所有马匹每天每匹饲喂混合牧草10 kg、颗粒精料3 kg,在此基础上试验组马匹每天每匹补喂5 mg来曲唑,进行30 d的饲喂试验和训练试验。分别在试验第0天、第10天、第20天、第30天清晨空腹颈静脉采血,测定血浆中激素指标;在试验第0天和第30天早晨空腹称重,并进行1 000 m速步赛,分别在赛前1 h、赛后即刻、赛后20 min、赛后2 h颈部静脉采集血液,测定血液酸碱度相关指标和血浆抗氧化指标。结果显示:补喂来曲唑能够提高试验马匹1 000 m速步赛成绩;赛后2 h时,试验组马匹血浆中过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活力,总抗氧化能力(T-AOC)及尿酸(UA)含量均高于对照组,其中GSH-Px活力、T-AOC分别达到极显著(P<0.01)和显著水平(P<0.05),而血浆中丙二醛(M DA)含量则显著低于对照组(P<0.05)。就血液酸碱度相关指标而言,在赛后即刻、赛后20 min、赛后2 h试验组血液中碳酸盐(HCO-3)含量低于对照组(P>0.05),而碱剩余(BEecf)、p H则高于对照组(P>0.05)。试验第10天、第20天、第30天时试验组马匹血浆中睾酮(T)、雄烯二醇(AD)水平均高于对照组(P>0.05)。此外,补喂来曲唑还可提高速步马体重。因此,给速步马补喂5 mg/(匹·d)来曲唑可缩短1000 m速步赛比赛用时,提高机体的抗氧化能力和酸碱缓冲能力,并使血浆中T和AD水平上升,同时增加速步马的体重。

This experiment aimed to study the effects of supplemental feeding letrozole on athletic performance,plasma antioxidant indices and hormone levels,and body weight of trotters.Ten health Yili male horse with 2.5 years old and the average body weight of（398.16 ± 25.34） kg,and similar performance based on strict training were randomly divided into 2 groups（control group and trial group）,and each group had 5horse.Each horse was fed with 10 kg mixed pasture and 3 kg pelleted concentrate every day,based on this,each horse of trail group was fed with 5 mg/d letrozole,and 30 d supplemental feeding experiment and training experiment were conducted.At days 0,10,20 and 30 of the experiment,blood samples were collected in the morning from jugular vein to determine the levels of hormones.Body weight was recorded at days 0 and 30 before ingestion in the morning.The 1 000 m trot training race was carried at days 0 and 30,and blood samples were collected from jugular vein at 1 h before the race,the end of the race,20 min after the race and 2 h after the race to determine the plasma antioxidant indices and blood acid-base degree related indices.The results showed as follows：supplemental feeding letrozole could increase the performance of 1 000 m trot training race of trotters.The enzyme activities of catalase（CAT）,glutathion peroxidase（GSH-Px）,superoxide dismutase（SOD）,the total antioxidant capacity（T-AOC） and the content of uric acid（UA） in plasma in trial group were higher than those in control group at 2 h after the race,and the activity of GSH-Px and T-AOC reached extremely significant（P〈0.01） and significant level（P〈0.05）,respectively,while the malondialdehyde（MDA） in plasma in trial group was significantly lower than that in control group（P〈0.05）.In aspect of blood acid-base degree related indices,the content of HCO-3in blood in trial group was lower than that in control group（P〈0.05）,while the BEecf and p H in blood in trial group were higher than those in control group（P〈0.05） at the end of the race,20 min after the race and 2 h after the race.The levels of testosterone（T）and androstenediol（AD） in plasma at days 10,20 and 30 of the experiment in trial group were higher than those in control group（P〉0.05）.In addition,supplemental feeding letrozole could increase the body weight.Therefore,supplemental feeding 5 mg/（horse·d） letrozole for trotters can shorten the using time of the 1 000 m trot training race,increase the antioxidant ability,the acid buffering capacity,the levels of T and AD in plasma and the body weight.