Effect Of Dietary Supplementation Of Thyme Oil On Production Performance And Antioxidant Ability Of Dairy Cows

The over-use of antibiotics in the diets of dairy cows is harmful for health of human and the ecological environment.But the plant extract thyme essential oil not only has a significant antibacterial effect,but also could enhance the anti-oxidation ability and relieve oxidative stress of animal.The oxidative stress of dairy cows could affect the lactation performance and hoof disease;thus,this paper took two parts study,the first part studied the effect of thyme oil on the dairy cow performance,milk composition and milk flavor.The second part studied the effect of thyme oil on the antioxidant ability and hoof disease of dairy cows.This study could provide some mechanistic insights into the application of plants extract on alleviate oxidative damage and hoof disease for improving performance of dairy cows.First part: This study measured the effect of thyme oil on the performance,milk composition and milk flavor.We chose 10 dairy cows per group with same diet and parity,and similar body weight(553 kg±43 kg),milk yield and days in milk.This study was administered 3 treatments were CON: control group(no thyme oil);LTO: low thyme oil group(control diet+20 mg/kg thyme oil);HTO: high thyme oil group(control diet+40 mg/kg thyme oil).First 7 days of preliminary experiments,then enter the trial period,each period lasted 10 d.This result showed that the DM intake(P<0.05),milk yield(P<0.05)and the concentration of lactose in the milk(P<0.05)were significantly improved in the LTO group,but the somatic cell count in the milk(P<0.05)was significantly decreased.There is a tread that the concentration of milk protein was decreased(P=0.08)and no effect on milk flavor.But the performance and milk composition milk flavor were not changed in the HTO group.Second part: This study measured the effect of thyme oil on the antioxidant ability and hoof disease.Our result showed that the level of T-AOC in the serum(P<0.05)was significantly increased in the LTO group.There was a tread that the level of SOD(P=0.09)was increased and the level of MDA(P=0.05)was decreased in the LTO group.But there is no effect on concentration of GSH-Px in the serum and hoof disease in the dairy cows with 20 mg/kg thyme oil.But the dietary supplement with 40 mg/kg thyme oil had not affected the performance and hoof disease of dairy cows.Then,based on the result in our study,we suggested that the thyme oil may improve dairy cows by relieve oxidative stress and inflammation response and increase the feed intake.