The effects of rotected methionine and lysine on milk yield and milk composition in holstein dairy cows

In the current study, the effects of rumen protected methionine and lysine was evaluated in terms of milk yield, milk composition, and feed efficiny in primiparous Holstein dairy cows. In the study, 0-21 days after delivery; one with control and the other with the experimental group 22-60 days of lactation; The study group was divided into four groups; one was the control group and the other was the experimental group. A total of 200 Holstein dairy cows with 50 animals in each group were used in the experiment. While the control animals consumed the basal diet, the experimental group consumed a basal diet containing rumen protected methionine and lysine (10/100 g) diet. During the trial, drinking water was available all the time in front of dairy cows. Milk yields and feed consumption were measured daily and milk compositions were analyzed weekly. At the end of the experiment, it was determined that methionine and lysine supplementation significantly increased the milk yield in both feeding periods (0-21.day, 22-60. day) (P<0.05). The addition of rumen protected methionine and lysine significantly increased the dry matter consumption in the first feeding period (1-21 days), but it did not affect (P>0.05) dry matter consumption in the second feeding period (22-60 days). This affect influenced the feed efficiency. Feed efficiency was unaffected by the treatments in the first period of feeding but in the second period the feed effiency was found to be higher in supplemental group. It was observed that rumen protected methionine and lysine increased the percentage of milk fat in both feeding periods (P<0.05) but did not affect the other milk composition parameters (P>0.05). Use of methionine and lysine additive in dairy cows was found to have a net return to the enterprise of +2,60 TL/day/animal.