Effect Of Rumen Protected Lysine On Performance And Blood Indexs In Dairy Cow

The objective of this study was to evaluate the effects of rumen protected lysine on lactation performance and blood biochemical parameters of Holstein dairy cows. Thirty-two multiparous cows in mid-lactation were randomly divided into four groups (eight each group ). The RPLys added to all groups 48 gram per head per day, and the doses of RPMet were 48, 39, 30 and 21 gram per head per day for different groups, respectively. The doses of RPMet were0, 10, 20 and 30 gram per head per day for different groups, respectively. Total duration of the experiment was seven weeks following 10 days for adaptation. The rustlts showed that, adding rumen protected lysine to diet, DM intake was not affected. There are no significant difference in fat percentage, lactose, milk solid content, plasma concentration of non-esterifed fatty acid, albumin, and glucose (p>0.05). The level of plasma concentration of total protein in the treatmentâ…¢was higher than that of the other groups. Concentrations of urea nitrogen in serum in the treatmentâ…¢was lower than that of the other groups(p<0.05). These results indicated that, adding rumen protected essential amino acid to diet and reducing protein level, the best doses of RPMet was 30 gram per head per day. On the basis of adding 30 gram RPMet, the productivity of dairy cattle could be improved and the amount of nitrogen that enters the environment be decreased.