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Effects of a Rumen Protected Lysine (AjiPro®-L) supplementation on peripartum disease, reproduction and lactational performance of dairy cows
One hundred eight multiparous cows were used to examine the effects of feeding AjiPro®-L (Ajinomoto Co., Inc., Tokyo, JAPAN) 21 d pre- through 21 d postpartum and then withdrawal. Cows were assigned to 1 of 4 pre/postpartum regimens: a) Control:Control (C/C), b) 100g AjiPro®-L:Control (A/C), c) Control:150g AjiPro®-L (C/A) and d) 100g AjiPro®-L:150g AjiPro®-L (A/A). All cows started their treatment regime 21 d prior to expected calving date through 21 d postpartum (Phase 1). Upon completion of the 21 d postpartum period, all cows were moved to a common group and fed the same diet without AjiPro®-L (Phase 2, 21-63 DIM). Individual DMI and milk yield were measured daily, and milk components weekly throughout both phases. Body weights, BCS, health incidence were recorded. During Phase 1, DMI was not affected in the prepartum period by AjiPro®-L inclusion. Postpartum, cows on A/C consumed more (P = 0.05) DM than C/C and C/A, with A/A cow not being different. Milk yield was highest (P = 0.04) for cows receiving A/A compared to C/C, with other treatments not being different. Milk fat yield was higher (P = 0.04) for cows supplemented with A/A compared to C/C and C/A, but not different from A/C. Cows receiving the C/A had higher milk protein percentage than A/C and A/A and not different from C/C. Milk fat percentage and milk protein yields were not affected by treatment regimens. During phase 2, no differences in body weight, BCS or milk yields were observed. Milk fat yield was higher (P = 0.05) for A/C and A/A cows compared to C/A with C/C not being different. Milk protein percentage was higher (P = 0.02) for C/A cows than those on C/C or A/A regime, with A/C not being different. Cows on A/C had higher (P = 0.05) milk fat percentage than C/C and C/A, not being different than A/A. Cows on A/C exhibited lower incidences of displaced abomasum and ketosis than other regimens. These results suggest that AjiPro®-L supplementation both pre- and postpartum generally resulted in the most consistently positive production performance immediate postpartum than other regimens. It was also suggested that feeding AjiPro®-L only prepartum had some specific effects on postpartum health status and production performance.
Keywords: lysine, milk production, transition period