Effects of lysine intake during late gestation and lactation period on milk composition in multiparous dairy cattle

The aim of this experiment was studying the effects of lysine in take in pre and postpartum period on production, milk composition, blood metabolite and some reproduction hormones of Holstein cows. In this trial 90 multiparous cow randomly divided to three groups of 30 dairy cows. Dairy cows were allocated to treatments included of control (without lysine), lysine (20 gm/daily/cow) and lysine (40 gm/daily/cow) groups. Lysine used as top-dress with diet from ten days before calving probably to eight weeks after parturition. Blood and milk samples were collected weekly from the calving time to eight weeks of lactation. Blood metabolite (glucose, insulin, urea, creatinine and triglyceride) were evaluated by kit at laboratory and Production, Milk composition and udder immune system was estimated by milk recording, milkoscan system and count of somatic cells (SCC). However, LH and FSH were analyzed at 15 and 25 days postpartum. The results showed that lysine group (20 gm) significantly increase milk production (P<0/05). The milk of protein, lactose, total solid and SNF was higher in lysine groups (20 & 40 gm) at more weeks of experiment. Level of SCC was significantly low in lysine groups (20 & 40 gm) compare than to control group (P<0/05). Level of insulin and urea was significantly high in lysine groups (20 gm particularly) at more weeks of experiment (P<0/05). It was concluded that adding of lysine had more beneficial effects on production, milk composition and levels of glucose, insulin, urea, creatinine, triglyceride and LH and FSH in Holstein cows.