Effect of protein level and methionine supplementation on dairy cows during the transition period

Cows experience a significant negative protein balance during the first 30 d of lactation. Given functional effects AA on health, especially in challenging periods such as calving, higher levels and specific diet may act to improve health feed intake. The response dairy cows 3 supplementation strategies transition period through 45 milk was evaluated. final data set had 39 Holstein blocked based parity (primiparous vs. multiparous) expected calving randomly assigned within each block one dietary treatments: low (LP), high (HP), or plus rumen-protected methionine (HPM). Treatments were offered from ?18 ± 5 relative parturition. Pre- postpartum diets formulated for metabolizable (MP) supply soybean meal, HP HPM provided MP than LP. Preplanned contrasts LP versus HP+HPM HPM. Significance declared at P ? 0.05 trends < 0.10. fed greater fry matter intake (DMI) prepartum (+2 kg/d), there trend DMI with (+1.6 kg/d). Body weight condition score before after did not differ among treatments. High (HP HPM) tended increase yield lactation (+1.75 increased lactose content urea-N plasma, blood BHB 14 postpartum, reduce milk/DMI compared Blood concentrations calcium glucose, nonesterified fatty acids pre- differ. induced lower concentration plasma IL-1 lowered lymphocytes 21 suggestive reduced inflammatory status IL-10, tumor necrosis factor alpha, other hemogram variables Addition alter but fat total solids concentrations. no effect metabolites immunity markers, exception pre-partum insulin indicate that around respond positively an by increasing improving immune status.