Effects Of Different Doses Soy Isoflavones On Growth Performance,Immune Function And Serum Biochemical Indexes Of Holstein Calves

In order to study the effects of diferent doses of soy isoflavone(SIF)on the production performance,immune correlation and serum biochemical indexes of Holstein calves,analyze the correlation with hormones,endocrine,energy metabolism and immune system,and preliminarily explore the specific mechanism of SIF on Holstein calves and the appropriate amount of SIF in calf diet.Forty 30±10 days old Holstein calves with good body condition and similar body weight were randomly divided into four groups,TG Ⅰ(100 mg/d),TG Ⅱ(300 mg/d),TG Ⅲ(600 mg/d)and CON group(control group).The test is divided into four parts:The first part studied the effect of SIF on the growth performance and diarrhea of Holstein calves.The results showed that:1.The daily gain of test group was higher than that of CON group in the whole period(0-60 days)and each period(0-20 days,20-40 days,40-60 days).The daily gain of TG Ⅱ group was the highest.The daily weight gain of TG Ⅲ group was significantly higher than that of CON group,TG I and TG Ⅱ group(P<0.05)at 40-60 days,and significantly higher than that of CON group(P<0.01)and TG Ⅰ and TG Ⅱ group(P<0.05)at the whole test period.2.The body weight of the test group was higher than that of the CON group in the whole test period and each period(except 0 d),and the TG Ⅱ group had the highest body weight.The body weight of TG III group was significantly higher than that of CON group(P<0.05).3.There were no significant differences in body height,oblique length,cruciform height,chest circumference,abdominal circumference and tube ceircumference between the groups in the whole test period and each period(P>0.05).4.The diarrhea rate and frequency of TG Ⅲ group were significantly lower than those of con group(P<0.01),the test group was not higher than CON group in the whole test period and each period,and the TG Ⅱ group had the lowest diarrhea rate and frequency.The second part studied the effect of SIF on the immunity and antioxidation of Holstein calves.The results showed that:1.IgA in the experimental group was significantly higher than that in the CON group(P<0.01)in the whole test period,and it was significantly higher in the experimental group than that in the CON group(P<0.01)on the 30th day of the test,and it was significantly higher in the experimental group than that in the CON group(P<0.01)on the 60th day of the test.The IgG level of the test group was significantly higher than that of the CON group(P<0.01)in the whole test period,and that of the TG Ⅲ group was significantly higher than that of the CON group(P<0.01)in the test 30 days,and that of the TG Ⅱ and TG Ⅱ groups was significantly higher than that of the CON group(P<0.05)in the test 60 days.The IgM of TG Ⅰ and TG Ⅱ group was significantly higher than that of CON group(P<0.01).IFN-y in TG Ⅱ and TG Ⅱ group was significantly lower than that in CON group(P<0.01)on day 0 and significantly higher than that in CON group(P<0.05)on day 60.IL-1 β in TG Ⅲ group was significantly higher than that in CON group(P<0.05).IL-4 in TG Ⅱ and TG Ⅲ group was significantly higher than that in CON group(P<0.01).TNF-α in the experimental group was significantly lower than that in the CON group(P<0.01)in the whole period of the experiment.At the 30th day of the experiment,the TNF-α in the TG Ⅲ group was significantly lower than that in the CON group(P<0.01).At the 60th day of the experiment,the TNF-α in the TG Ⅱ and TG Ⅲ group was significantly lower than that in the CON group(P<0.05).2.The CAT level in the test group was significantly lower than that in the CON group(P<0.05)in the whole test period,and that in the test group was significantly lower than that in the CON group(P<0.05)in the test 30 days,and that in the TG Ⅲ group was significantly lower than that in the other groups(P<0.01)in the test 60 days.GSH-Px in the test group was significantly higher than that in the CON group(P<0.01)in the whole test period,significantly higher than that in the CON group(P<0.01)in the test 30 days,and significantly higher than that in the CON group(P<0.01)in the test 60 days.The T-AOC of the experimental group was significantly higher than that of the CON group(P<0.01)in the whole period of the experiment.At the 30th day of the experiment,the T-AOC of the experimental group was significantly higher than that of the CON group(P<0.01).At the 60th day of the experiment,the TG Ⅲ group was significantly higher than that of the other groups(P<0.01).SOD in the test group was significantly higher than that in the CON group(P<0.01)in the whole test period,and it was significantly higher in the test group than that in the CON group(P<0.01)in the test 30 days.MDA in the test group was significantly lower than that in the CON group(P<0.01)in the whole test period,and it was significantly lower in the test group than that in the CON group(P<0.01)in the 30 days of the test.The third part studied the effect of SIF on the level of endogenous hormones in Holstein calves.The results showed that the GH of TG Ⅱ and TG Ⅲ group was significantly higher than that of CON group(P<0.01)in the whole test period.At 30 days,the GH of TG Ⅱ and TG Ⅲ group was significantly higher than that of CON group(P<0.01).At 60 days,the GH of TG Ⅲ group was significantly higher than that of CON group(P<0.01).IGF-Ⅰ in TG Ⅲ group was significantly higher than that in CON group(P<0.01)in the whole test period,IGF-Ⅰ in TG Ⅱ and TG Ⅲgroup was significantly higher than that in CON group(P<0.01)in the test 30 days,and in TG Ⅲ group was significantly higher than that in CON group(P<0.01)in the test 60 days.There was no significant difference in T3 between each group in the whole test period and each test period(P>0.05).T4 in the experimental group was significantly higher than that in the CON group(P<0.05)in the whole test period,and it was significantly higher in the experimental group than that in the CON group(P<0.01)at the 30th day of the test.Ghrih in TG Ⅱ and TG Ⅲ group was significantly lower than that in CON group(P<0.05)in the whole test period.At 30 days,ghrih in TG Ⅱ and TG Ⅲ group was significantly lower than that in CON group(P<0.01).The fourth part studied the effect of SIF on the serum biochemical indexes of Holstein calves.The results showed that the TP in the experimental group was significantly higher than that in the CON group(P<0.01)in the whole test period,and the TP in the experimental group was significantly higher than that in the CON group(P<0.01)at 30 days.The alb of the experimental group was significantly higher than that of the CON group(P<0.05)in the whole test period,and the alb of the experimental group was significantly higher than that of the CON group(P<0.01)in the 30 days of the test.The GLB of TG Ⅲ group was significantly higher than that of CON group(P<0.05)in the whole test period,and that of TG Ⅱ and TG Ⅲ group was significantly higher than that of CON group(P<0.05)in the 30 days of the test.The FFA of the experimental group was significantly lower than that of the CON group(P<0.01)in the whole test period,and the FFA of the experimental group was significantly lower than that of the CON group(P<0.01)in the 30 days of the test.Conclusion:feeding SIF can improve the growth of Holstein calves,reduce the diarrhea rate of calves,and then promote the growth of Holstein calves;SIF can inhibit the synthesis and secretion of serum TNF-α and improve the immune performance by promoting the synthesis and secretion of serum IgA,IgG,IgM,IFN-γ,IL-1β,IL-4;it can also improve the activity of serum GSH-Px,TAOC,SOD,reduce the content of serum MDA.Improve the anti oxygen performance;SIF can improve the level of GH,IGF-I,T4,decrease the level of GH,regulate the level of growth related hormones,increase the level of TP,ALB,GLB,reduce the concentration of FFA,and improve the internal environment of nutrient metabolism;In conclusion,SIF can improve the immune and antioxidant performance of Holstein calves,regulate the level of growth related endogenous hormones and improve the internal environment of Holstein calves,The optimum feeding doses was 600 mg/d and the feeding time was more than 40 days.