Effects Of Supplementation Of Vitamin E And Ethyl Pyruvate Into The High Concetrate Diet On Immune Response And Growth Performance In Beef Cattle

In practical production, the breeding industry of beef cattle gradually to large scale and intensive, High grain diets are widely used. Cattle are fed high concentrate diets to meet the demands of energy and nutrients for their rapid growth, but this pattern also decreases the ruminal pH and causes rumen acidosis, rusulting in rumen microflora changes and abnormal fermentation in rumen, then a large amount of endotoxin(LPS)and histamine will be released in the rumen. High concentrations of LPS and histamine can be translocated into the bloodstream through the digestive tract barriers, and change the body immune function and metabolic, cause the systemic inflammation, thereby reducing the growth performance of cattle. Vitamin E(VE) and ethyl pyruvate(EP)have the function of anti-oxidant, and their anti-inflammatory effects have been proved in animal models. However, there are only a few reports about their role in reducing the adverse effect of LPS and histamine in cattle fed high concentrate diets. Therefore, our study supplement VE and EP into diets, and investigate their effect on growth performance, inflammation reaction and selective feed ingestion in beef cattle.Trial 1: Eighteen beef cattles(Simmental× Luxi) with an initial body weight(BW)of 440.92 ± 30.21 kg were evenly selected and randomly divided into 3 treatments. The3 treatments were the control group, VE group and EP group. The group of control fed the basal diet, the VE group fed the basal diet + 100IU/kg VE and the EP group fed the basal diet + 0.2% EP, respectively. The duration of the trial was 35 days. The result showed:(1) Dietary supplementation of VE and EP had no significant effect on rumen pH(P>0.05), but they significantly decreased the concentration of LPS in rumen fluid(P<0.01). Dietary supplementation of VE significantly decreased the concentration of histamine in rumen fluid(P<0.05), Dietary supplement EP decreased histamine concentration in rumen fluid(P>0.05).(2) Dietary supplementation of VE and EP significantly decreased the concentration of LPS and histamine in plasma.(3) Dietary supplementation of VE and EP decreased the plasma IL-1β by 8.36% and 3.48%,TNF-α by 7.67% and 27.53%, respectively(P>0.05). Moreover they significantlydecreased the levels of IL-6, IL-8 and acute phase protein(P<0.05).Trial 2: Eighteen beef cattles(Simmental× Luxi) with an initial body weight(BW)of 440.92 ± 30.21 kg were evenly selected and randomly divided into 3 treatments. The3 treatments were the control group, VE group and EP group. The group of control fed the basal diet, the VE group fed the basal diet + 100IU/kg VE and the EP group fed the basal diet + 0.2% EP, respectively. The duration of the trial was 35 days. The result showed:(1) Dietary supplementation of EP increased(P>0.05) crude protein(CP), acid detergent fiber(ADF), total phosphorus(TP) apparent digestibilities, and significantly increased(P<0.05) calcium(Ca) apparent digestibilities. In addition, Dietary supplementation of EP increased(P>0.05) average daily gain(ADG), and improved feed efficiency(P<0.05).(2) Dietary supplementation of VE had no significant effect on apparent digestibilities, but had the trend on increased average daily gain(ADG), and improved feed efficiency(P<0.05).Trial 3: Six beef cattles(Simmental× Luxi) had similar body condition were randomly selected and housed in tie stalls individually, each of them fed three concentrates, including basal concentrate without adding VE or EP, the basal concentrate + 100IU/kg VE and the basal concentrate + 0.2% EP at the same time. The duration of the trial was 7 days. The results showed:(1) During 3-4 days of the trial period, concentrate supplementation of EP decreased average daily matter intake(ADMI) and the percentage of daily feeding times in beef cattle(P<0.05).(2) After the adaptation period, concentrate supplementation of EP had no significant effect on ADMI and the percentage of daily feeding times in beef cattle(P>0.05).