Effects Of Guanidine Acetic Acid And Methyl Donor On Exercise Performance And Blood Antioxidant Capacity Of Yili Horse

The purpose of this experiment was to explore the effects of guanidine acetic acid(GAA)and different methyl donors on the content of blood creatine metabolites and sports performance of Yili horses,and to provide scientific reference for the application of GAA in speed racing horses.The purpose of this experiment is to explore the effects of guanidine acetic acid(GAA)and methyl donor on the exercise performance and blood antioxidant capacity of Yili horses,and to provide scientific reference for the application of guanidine acetic acid in speed racing horses.Experiment 1: Twenty Yili horses aged 2-3 years old and with similar body weight [(373.2±30.53)kg] were randomly divided into 4 groups,5 horses in each group(3♀+2♂),and received equal intensity training every day.Each horse was fed with concentrate supplement of 4 kg,per day for free feeding of green hay.On this basis,each horse of each group was fed with guanidine acetic acid of 0(CON group),25(25 GAA group),50(50 GAA group)and 75 mg/kg BW(75GAA group)for 8 weeks.Blood and urine samples were collected on the 1st,3rd,5th,7th,10 th and 36 th day of the experiment.2000 m speed race was conducted on the 47 th day,and blood and urine samples were collected.The results showed that: 1)Supplementation of different levels of GAA can improve the performance of Yili horse 2000 m race.2)The plasma Cr/GAA of horses in each experimental group was higher than that in CON group before feeding and 2 to 9 hours after feeding(P<0.01).24 h urinary creatine and creatinine excretion in all experimental groups were higher than those in CON group(P<0.01).3)The activity of plasma creatine kinase in 50 and 75 GAA groups was higher than that in CON group immediately after competition(P<0.01).At the same time,50 GAA group was higher than 75 GAA group(P<0.01).The contents of insulin,blood glucose and lactic acid in each experimental group before and after the race were significantly higher than those in the CON group(P<0.05).The activities of plasma total antioxidant capacity,glutathione peroxidase and superoxide dismutase in all experimental groups were higher than those in CON group 2 hours before and 2 hours after competition(P<0.05).Experiment 2: Twenty Yili horses aged 2 years and with similar body weight [(418.40±39.37)kg] were randomly divided into 4 groups with 5 horses in each group(3♂+2♀)and received equal intensity training every day.Each horse was fed with concentrate supplement for 4 kg,per day to freely feed on green hay.On this basis,each horse in each group was fed with 0(control group),60 mg/kg BW guanidine acetic acid(GAA group),60 mg/kg BW guanidine acetic acid and 30mg/kg BW betaine(GAA+Bet group),60 mg/kg BW guanidine acetic acid and 152 mg/kg BW methionine(GAA+Met group).The experiment lasted for 25 days.The results showed that: 1)Supplementation of GAA,GAA+Bet and GAA+Met could shorten the 2000 m race time of Yili horse.The average time consumption and performance improvement of GAA group was better than that of GAA+Bet group,and significantly higher than that of control group and GAA+Met group(P<0.05).2)The concentrations of plasma insulin and glucagon in the GAA group were higher than those in the control group immediately after the game and 2 hours after the game(P<0.05).At 2 hours before and immediately after the game,the level of GAA+Bet group was significantly higher than that of the control group(P<0.05).3)Two hours before the competition,the activities of plasma catalase,glutathione peroxidase and superoxide dismutase and the total antioxidant capacity in each test group were significantly higher than those in the control group(P<0.05).The concentration of MDA in the control group was lower than that in the control group(P<0.05).Under the conditions of this experiment,supplementation of GAA could improve the performance of Yili horse in 2000 m speed race,the content of plasma creatine metabolite,creatine kinase activity and the ability of antioxidation,promote the transport and absorption of guanidine acetic acid and the energy supply of glucose metabolism to exercise.Therefore,guanidine acetic acid can be used as a nutritional regulator to relieve exercise fatigue or promote fatigue recovery after exercise.At the same time,the forage contains enough methionine to provide methyl for the exercise horse,no additional methyl donor is needed,and the effect is best at 50 to 60 mg/kg BW.