Effect of nutrient levels during the far-off period on postpartum productivity in dairy cows.

The present study aimed to determine the effects of differing nutrient levels during the far-off period on postpartum metabolism and milk production in lactating cows. Twenty-six multiparous cows were assigned to three dietary treatments in the far-off period: a low-energy diet (L, n = 9, 80% intake of the total digestible nutrients requirement), a moderate-energy diet (M, n = 8, 105%) and a high-energy diet (H, n = 9, 130%). During the close-up period, all cows were provided with 105% intake. After parturition, all cows were fed a lactation diet. The BCS recovery was slow, and low milk yield was found in the H group. In the L group, BCS recovery was favorable after parturition, and lactation persistence was increased. The L group had low rumen endotoxin activity and a high initial ovulation rate after parturition. These findings indicate that a high-energy diet during the far-off period has a deleterious effect on milk production. In contrast, the restricted diet in the far-off period increased adaptability with respect to peri-parturition metabolic changes, improved the post-parturition nutritional state, and increased milk production. Furthermore, it suggests that the nutrient levels in the far-off period affect rumen endotoxin activity and reproductive function after parturition.