Effects Of Supplementation With β-hydroxy-β-methylbutyrate On Plasma Amino Acid Concentrations And Athletic Performance Of Yili Horse

The purpose of this study was to investigate the effects of diet supplementation with different doses ofβ-hydroxy-β-methylbutyrate(beta-hydroxy-beta-methylbutyrate,HMB)on the plasma amino acid concentrations and athletic performance of Yili horse.The application of HMB in Yili horse diet provides a scientific basis.The experiment selected a single factor multilevel research method.Twenty Yili horses with the similar body weight[(384.11±25.44)kg]and aged 2 years old,were divided into 4 groups with 5 horses(3♂+2♀)in each group,the training method and intensity were consistent.HMB was not supplemented in the control group,7.5 g HMB was supplemented in the trial group Ⅰ,15 g HMB was supplemented in the trial group Ⅱ,22.5 g HMB was supplemented in the trial group Ⅲ.The experiment was lasted for 31 days.Blood samples were collected 0 h before feeding,1 h,2 h,4 h after feeding on the 21 day of the experiment.A 2000 m speed race was performed on the 31 day of the experiment and blood samples were taken on pre-race 2 h,immediately at post-race,post-race 2h.The results showed that:1)Compared with control group,the plasma HMB concentrations of the trial group Ⅰ was increased by 179.59%at 0 h before feeding(P<0.05).The plasma HMB concentrations of the trial group Ⅱ and the trial group Ⅲ was increased by 279.29%and 425.74%than the control group at 0 h before feeding(P<0.01).At 1 h,2 h,4 h after feeding,the plasma HMB concentrations of the trial group Ⅰ was increased by 327.17%,361.45%,368.82%than that in the control group(P<0.01).The plasma HMB concentrations of the trial group Ⅱ was increased by 526.33%,629.28%,621.47%than that in the control group(P<0.01).The plasma HMB concentrations of the trial group Ⅲ was increased by 886.83%,1000%,1000.88%(P<0.01).After feeding HMB,the plasma HMB concentrations in the each test group showed a upward trend and reached a peak at 2 h after feeding.2)Compared with control group,the plasma asparagine,arginine,phenylalanine concentrations in the trial group Ⅰ was increased by 25.82%,23.13%,24.69%(P<0.05).The plasma arginine,lysine,serine,threonine concentrations in the trial group Ⅲ was increased by 23.57%,38.59%,24.39%,33.60%(P<0.05).But compared with the trial group Ⅰ,the plasma 3-methylhistidine concentrations was significantly higher in the trial group Ⅲ(P<0.05).3)Added HMB can short the time of the Yili horse 2000 m speed race.4)Compared with control group,the activity of phosphocreatine kinase in the trial group Ⅱ was decreased by 12.48%(P<0.05).The plasma lactate dehydrogenase activity in the trial group Ⅰ and the trial group Ⅱ was decreased by 7.38%(P<0.05)and 13.51%(P<0.01).The plasma lactic acid concentrations of the trial group Ⅱ and the trial group Ⅲ was decreased by 11.91%(P<0.05)and 19.57%(P<0.01).5)HMB supplemented did not have significant effects on the plasma a-ketoisocaproate,antioxidant capacity,glucose,insulin,glucagon metabolism and cholesterol level(P>0.05).Under the experimental conditions,supplemented different dose of HMB can increase the concentrations of HMB,asparagine,arginine,phenylalanine,lysine,serine,and threonine in Yili horses plasma,short the time of the Yili horse 2000 m speed race,decrease the plasma phosphocreatine kinase,lactate dehydrogenase activity and lactic acid concentrations.In conclusion,HMB can be used as a nutrient regulator to alleviate exercise horse fatigue or promote fatigue recovery after exercise.The recommended supplementary level of HMB in Yili horses diet is 7.5 g/d～15 g/d per horse.