Energy Status, Lipid-Soluble Vitamins, and Acute Phase Proteins in Periparturient Holstein and Jersey Dairy Cows With or Without Subclinical Mastitis

In a retrospective, case-controlled, observational study, associations among indices of negative energy balance, plasma lipid and lipid-soluble vitamin concentrations, plasma acute phase protein status, and occurrence of a new subclinical intramammary infection (IMI) during the periparturient period were determined. Cows were paired based on breed and expected parturition date (EPD) and monitored from the cessation of lactation through wk 8 of the subsequent lactation. A cow was identified as developing a new IMI if the intramammary pathogen isolated postpartum differed from that isolated in wk −9 (relative to EPD). Mean body condition score (BCS) of cows at wk −9 was 3.71 ± 0.12. Fifteen Holstein and 15 Jersey dairy cows met the study selection criteria. Cows with a new IMI had greater body condition score, body weight, and body weight loss compared with cows that did not develop a new IMI. Prepartum plasma concentrations of β-carotene were greater for Jersey cows with a new IMI compared with Jersey cows without a new IMI and Holstein cows, regardless of IMI status. However, there was a significant delay in recovery of plasma concentrations of β-carotene postpartum for Jersey cows with a new IMI compared with Jersey cows without a new IMI. Plasma α-tocopherol, albumin, and retinol binding protein concentrations were greater during the periparturient period for cows without a new IMI. Plasma haptoglobin was increased at wk 1 postpartum for cows without a new IMI. Milk protein and lactose percentages and milk urea N were decreased and somatic cell counts were increased in cows identified with a new IMI compared with cows that did not develop a new IMI. Dairy cows with greater tissue energy stores prepartum and reduced plasma proteins, β-carotene, and α-tocopherol had a greater risk for developing a new IMI during the periparturient period.