Effects Of Isoacids On Production Performance,Serum Biochemical,Antioxidant,and Immune Indicators In Perinatal Cows

Objective: isoacids is a type of organic acid acidifier that is a food supplement.It has the ability to control rumen fermentation,tolerate heat stress,and encourage the development and reproduction of bacteria that break down rumen fiber.In order to examine the impact of isoacids on performance and blood biochemical indices of perinatal dairy cows,different quantities of isoacids were given to the basal diet of Chinese Holstein dairy cows.To explore whether the addition and use of isoacids during the perinatal period can improve the production performance and enhance the antioxidant and immune capacity of the body,so as to provide reliable data support and theoretical basis for its application in the production practice in perinatal cows.Methods: Select 18 healthy,3rd parity postpartum Holstein cows.They were randomly divided into 3groups: the control group,the trial I group,and the trial II group,with 6 cows in each group and 1 cow in each replicate.Control group: Each cow was fed a basic diet only;Experiment Group I: Each cow was fed a basic diet of+30m L/d isoacids;Experiment Group II: Each cow was fed a basic diet of+60m L/d of isoacids.The pre-feeding period lasted for 10 days,and the trial period lasted for 42 days,from 21 days before to 21 days after delivery.Fecal samples of cows in each group were collected three times a day,in the morning,middle,and evening,from 19 to 21 days postpartum,and the apparent digestibility was determined.Rumen fluid was collected with an oral catheter at 21 days postpartum before morning feeding to determine rumen fermentation parameters.Three times of milk production were recorded at 10 and 21 days postpartum,and milk samples were collected to analyze milk composition.Blood was collected from the caudal vein at 10 days prenatal,on the day of delivery,and at 10 days postpartum and 21 days postpartum before morning feeding for the detection of serum biochemical indices,antioxidants,and immune indices.Results: Experiment 1: Effects of isoacids on the production performance in perinatal cows(1)Effects of isoacids on dry matter intake and apparent digestibility in perinatal cows: There was no significant difference(P>0.05)in the dry matter intake of cows in each experimental group during the early and late stages of perinatal period.The apparent digestibility of DM,CP,NDF,and ADF in group I and group II cows showed significant differences compared to the control group(P<0.05).(2)Effects of isoacids on rumen fermentation in perinatal cows : The concentrations of ammonia nitrogen in groups I and II were significantly lower than those in the control group(P<0.05);The content of microbial protein in groups Ⅰ and Ⅱ was significantly higher than that in control group(P<0.05);the concentrations of isoacids and total volatile fatty acids in group II were significantly higher than those in the control group(P<0.05);and the concentrations of isoacids and total volatile fatty acids in group I were,respectively,6.60% and 2.50% higher than those in the control group.(3)Effects of isoacids on lactation performance in perinatal cows: On postpartum day 10 and 21,compared with the control group,milk yield and milk fat percentage in groups I and II were significantly increased(P<0.05);there were no significant differences in milk protein percentage,lactose percentage,or urea nitrogen among all groups(P>0.05).Trial 2: Effects of isoacids to the diet in perinatal cows on serum biochemical,antioxidant,and immune indicators(1)Effects of isoacids on serum biochemical indices in perinatal cows: On the day of delivery,the albumin content in group I and control group was significantly lower than that in group II(P<0.05);At 10 days postpartum,the content of globulin in group I was significantly higher than that in the control group(P<0.05);on the day of delivery,the triglyceride content of group I was significantly lower than that of group II(P<0.05);On postpartum day 21,blood glucose concentrations in groups I and II was significantly higher than those in the control group(P<0.05);On postpartum day 21,blood glucose concentrations in groups I and II were significantly higher than those in the control group(P<0.05);At 10 days before delivery,The control group’s urea nitrogen concentration was significantly higher compared to groups I and II(P<0.05),and at 21 days after delivery,The urea nitrogen concentration in the control group was significantly higher than that in group II(P<0.05);At 10 days before delivery,The content of alanine aminotransferase in group I was significantly increased compared with that in control group(P<0.05);There were no significant changes in total cholesterol,high density lipoprotein cholesterol,or aspartic acid transferase before and after delivery.(2)Effects of isoacids on serum antioxidant indicators in perinatal cows: At 10 days before delivery,the glutathione peroxidase content in the control group was significantly lower than that in group I(P<0.05);At 10 days prenatal,glutathione peroxidase content in group I was significantly increased compared with control group(P<0.05),and at 21 days postpartum,the glutathione peroxidase content in group II was significantly higher than that in the control group(P<0.05);On the day of delivery,At 10 days before delivery,the glutathione peroxidase content in the control group was significantly lower than that in group I(P<0.05),and at 10 days after delivery,the malondialdehyde concentration in group II was significantly lower than that in the control group(P<0.05);On the day of delivery,the total antioxidant capacity concentration in group I was significantly higher than that in the control group(P<0.05),and 10 days after delivery,the total antioxidant capacity group II had a concentration that was substantially greater than the control group(P<0.05).(3)Effects of isoacids on serum immune indicators in perinatal cows: On postpartum day 10,the serum immunoglobulin A(Ig A)content in control group was significantly lower than that in group II(P<0.05);At10 days before delivery,The serum immunoglobulin G(Ig G)content in control group was significantly lower than that in groups I and II(P<0.05),and on the day of delivery,Serum Ig G content of the control group was significantly different from that of group II(P<0.05);day of delivery,the content of immunoglobulin M(Ig M)in group II was significantly different from that in the control group(P<0.05);On postpartum day 10,the content of immunoglobulin M(Ig M)in group I was significantly different from that in the control group(P<0.05).Conclusions: The supplementation of isoacids in perinatal diets can improve the apparent digestibility of nutrients in diets,reduce the concentration of ammonia nitrogen in the rumen environment,increase the contents of microbial protein,isoacids and total volatile fatty acids in the rumen,milk yield and milk fat percentage,and enhance the antioxidant and immune capacity of dairy cows.Overall,The optimal amount of isoacids added in this experimental study is 60 m L/d each cow.