Effects Of Tributyrin And Essential Oil On Growth Performance And Blood Indexes Of Female Calves

The healthy cultivation of calves is very important for the growth performance during growing period.Tributyrin(TB)and essential oil(EO)are two potential substitutes for antibiotics,however seldom research was about the effect of TB and EO on female calves.Therefore,this study aimed to research the effect of TB and EO on growth performance and blood indexes of female calves,and provide theoretical basis and technical reference for the rational application of TB and EO on calves.Specific research contents are as follows:A total of sixty healthy Holstein female calves at the age of 4 days were used the randomly complete block design with a 2×3 factorial arrangement with different combinations of TB and EO.Calves were randomly divided into 6 treatment groups with 10 replicates and 1 cow in each replicate,and the test lasted for 120 days(2 periods).The suckling period(day 4-65)diet: group A(0.1% of TB,EO 0.015%),group B(0.15% of TB,EO 0.015%),group C(TB0.2%,0.015%EO),group D(0.1% of TB,EO 0%),group E(0.15% of TB,EO 0%),group F(0.2% of TB,EO0%);growth period(day 66-120)diet: group A(0.05% of TB,EO 0.015%),group B(0.1% of TB,EO 0.015%),group C(0.15% of TB,EO 0.015%),group D(0.05% of TB,EO 0%),group E(0.1% of TB,EO 0%),group F(TB0.15%,0% EO).Experiment 1: Investigating the effects of TB and EO on growth performance of female calves.The results showed that: 1)Diets supplemented with different levels of TB and EO tended to increase the feed intake,and decrease diarrhea and mortality rate of calves during lactation period.2)0.15% TB and 0.015% EO significantly increased the average daily gain,body length and body height of calves from day 31 to 65(P<0.05).3)TB and EO did not significantly affect the average daily gain,body size and body size index of calves during the growing period(day 66 to 120).Experiment 2: Investigating the effects of combination of TB and EO on blood indexes of female calves.The results showed that: 1)Diet supplemented with 0.015% TB significantly decreased the concentration of Glu(P < 0.05),however,increased the concentration of BHBA in blood(P < 0.05).2)Diet supplemented with EO significantly increased the concentrations of GC,Ig G and Ig M concentrations during lactation period(P < 0.05),however,decreased the concentration of ROS in blood(P < 0.05).3)0.15% TB significantly decreased the levels of INS and BUN(P < 0.05)and 0.1% TB significantly decreased the levels of Ig M during growth period(P < 0.05).4)Diet supplemented with EO decreased the concentrations of GC and ALB(P < 0.05),but EO did not significantly influence the immune indexes and oxidative stress indexes during growth period.In conclusion,0.15% TB and 0.015% EO can increase the growth performance of calves,improve the changes of blood indexes caused by weaning stress,reduce the risk of calf diarrhea and improve the survival rate of calves during lactation period.TB and EO did not affect the growth performance and blood index of calves.