Abstract
Four multiparous Holstein lactating dairy cows were used to evaluate the effect of addition of green tea grounds silage (TGS) on feed intake, milk production, rumen fermentation and blood component. The cows were housed in a 4×4 Latin square design for a 15d periods. Total mixed rations (TMR) contained 30% timothy hay, 15% alfalfa pellets and 55% concentrate on a dry matter basis. TGS was added at 0, 5, 10, or 15% of the TMR dry matter. TDN, CP and NDF in all diets were adjusted to 71%, 16% and 36%, respectively. The dry matter intake decreased along with the increase of TGS in TMR. The 15% treatment significantly decreased the intake (P<0.05) compared to 0% and 5% treatment. The production of milk tended to decrease in the 10% treatment and significantly decreased (P<0.01) in the 15% treatment. The milk fat percentage and milk protein percentage were not affected by the treatments, but the milk lactose percentage significantly decreased (P<0.05) when TGS was added at 15% of the TMR dry matter. There were no differences in the ruminal pH and concentrations of volatile fatty acids among the treatments. The mole percentage of propionic acid of rumen liquor significantly (P<0.05) decreased in the 15% treatment. Compared to the 0% treatment, the concentration of rumen ammonia-nitrogen and the plasma concentration of urea nitrogen were significantly low (P<0.05) in the 10% and 15% treatments. These results showed that addition of 5% TGS of the diet on the dry matter basis did not affect the performance of midlactating cows.
