Effects of adding the oregano essential oil to the total mixed ration on production performance and incidence of hoof disease of lactating Holstein dairy cows

The present study was carried out to investigate the effects of adding oregano essential oil to the total mixed ration (TMR) on TMR temperature, dry matter intake, milk yield and incidence of hoof disease of lactating Holstein. Based on similar performance paired principle, 72 healthy Holstein dairy cattles were divided into two groups including trial group milk production (29.88±8.55) kg·d-1, 0.028 kg·d-1 oregano essential oil in TMR and control group milk production (29.15±7.07) kg·d-1, no oregano essential oil in TMR. The results showed that the temperature increasing rates of the trial group diet were significantly lower (P<0.05) than those of the control group which took place at 17:00 in June, 13:00 and 17:00 in July and August. The dry matter intake of trial group cattle was significantly higher than that of control group (P<0.05) in May, and very significantly higher than that of control group (P<0.01) in June, July and August. The milk yield of trial group cattle were very significantly higher than that of control group (P<0.01) in June, July, August and September. There was no significant difference between the trial group and control group for the incidence of hoof disease. In conclusion, an addition of 0.028 kg·head-1·d-1 oregano essential oil can reduce the temperature of TMR, and improve the palatability of TMR and the freshness of TMR, and increase dry matter intake and milk yield, especially for Holstein dairy cattle during the summer periods in the north when temperatures are high.