| The growth performance,antioxidation function of goats would be greatly affected under high temperatures and humidities environment.This study was carried out to investigate the variation of growth performance,urine and serum biophysiological-biochemical index in goats under different temperatures and relative humidities(RH).The objective of this study was to provide theoretical reference for breeding,the formulation of mitigation measures and disease diagnosis of goats under high temperatures and humidities.Exp.1 Effects of temperatures and relative humidities on growth performance,urine and blood routine of goatsAccording to 4×4 factorial design of four temperatures(26 °C,30 °C,34 °C and 38 °C)and four RH levels(35%,50%,65% and 80%),eight healthy Boer goat × Sannen dairy goats(approximate 1.5 years old)with similar body weight were used in this study.The goats were randomly allotted to 2 treatments,each group included four goats and one goat was a replicate.The adaptation period lasted for 30 days in the natural environment.The experiment period of each group was 5 days and the treatment was 24 hours every day.According to the different treatments,the experiments were carried out in the artificial environment control cabin in turn.Results showed that interaction of temperature and RH significantly affected average daily feed intake and average daily water intake(P<0.05),average daily feed intake of goats at each treatment group under 38 °C was significantly lower than that at each treatment group under 26 °C(P<0.05).Interaction of temperature and RH didn't significantly affected the average daily gain,weight ratio and blood routine indexes(P>0.05).On day 3,WBC in blood of goat at 38 °C was significantly lower than those at 26 °C and 30 °C(P<0.05),while on day 5,WBC in blood of goat at 34 °C and 38 °C was significantly higher than that at 26 °C(P<0.05).The WBC,RBC,Hb and HCT in blood of goat on day 5 was lower than those on day 3,but the MCHC in blood of goat was higher than those on day 3.And with the elongation of time,there were no obvious changes on MCH,MCV and RDW in blood.Average daily feed intake of goats was significantly positive correlated with WBC(P<0.05),and highly significantly negative correlated with Hb(P<0.01).Exp.2 Effects of temperatures and RH on biochemical indicators,inorganic ions,antioxidant indicators and enzymes activity in serum of goatsThe experimental design was identical with the experiment 1.On days 3 and 5,blood was sampled,and the serum samples were used to determine serum biochemical indicators,inorganic ions,enzymes activity and antioxidant indicators.Results showed that:(1)On day 3,interaction of temperature and RH significantly affected content of serum K,activity of ALT and AST of goats(P<0.05).The content of serum K at 38 °C,80% was significantly lower than that at other groups(P<0.05).Compared with 26 °C and 30 °C,the concentrations of GLO,GLU,BUN,Ca and ALP in serum at 38 °C were significantly lower(P<0.05).The GLU and BUN contents in serum at 80% RH were significantly lower than those at 35% RH(P<0.05).(2)On day 5,interaction of temperature and RH significantly affected contents of TP,ALB,GLO,BUN,Ca,P,K,Na and activity of LDH in serum of goats(P<0.05).The GLU,Cl,ALT,AST,ALP and CK concentrations in serum at 34 and 38 °C were significantly lower than those at 26 °C(P<0.05).The GLU and Cl concentrations in serum at 60% and 80% RH were significantly lower than those at 35% RH(P<0.05).(3)Compared with each group at 26 °C,the concentrations of T-AOC,SOD,CAT and GSH-Px in serum of goats at 38 °C,80% and 38 °C,65% were significantly lower(P<0.05).The concentrations of MDA in serum of goats at 34 and 38 °C was significantly higher than that at 26 °C(P<0.05).(4)The concentrations of TP,ALB,GLO,BUN,GLU,TC,TG,Ca,P,ALT,AST,ALP,LDH and CK in serum on day 5 was lower than that on day 3,but the MDA in serum was higher than that on day 3 and T-AOC,SOD,GSH-Px in serum on day 5 in 34 and 38 °C was higher on day 3.(5)Average daily feed intake of goats was extremely significantly positive correlated with BUN,GLU,ALT,ALP,T-AOC,SOD,GSH-Px,CAT in serum(P<0.01),and it was significant negative correlation with Na,Cl,CK in serum(P<0.05).Based on the results from above experiments,temperature,RH and their interaction affected the average daily intake,average daily water intake,serum biochemical indicators and antioxidant indicators of goats.Higher temperature and higher humidity environment had negative effects on the growth performance,metabolic performance,antioxidation function of goats.Among those different conditions,38 °C with 80% RH had the most serious effects on the goats' physiological parameters.While the growth performance and blood routine indexes of goats were also affected by the processing time.There were some correlation between some indexes. |
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