Cows with feed restriction–induced hyperketonemia early postpartum have a different immunometabolic profile than healthy cows or cows with inflammatory disorders

Immune activation and subsequent inflammation lead to difficult transitions from pregnancy to lactation. Whether postpartum hyperketonemia can occur independently of immune activation remains controversial. Our objective was to compare immunometabolic profiles in blood serum from healthy cows, healthy feed-restricted cows, and cows with naturally occurring inflammatory disorders. Multiparous Holsteins (n = 32) were fed a dry period diet until parturition. After parturition, all cows were fed a lactation diet at ad libitum intake until 5 DIM. At 4 DIM, cows underwent a thorough physical examination by a veterinarian and were classified as healthy (n = 15) or having at least 1 periparturient disorder or disease (n = 17), which were inflammatory conditions. Healthy cows were assigned to a control ad libitum-fed group (CON; n = 6) or to a group subjected to 50% feed restriction beginning at d 5 (FR; n = 9) and continuing until diagnosis of clinical ketosis or d 14, when they were returned to ad libitum DMI. The periparturient inflammatory disorders (PID; n = 17) group consisted of cows with metritis, retained placenta, foot and leg problems, or mastitis. During the dry period, the serum ratio of albumin:globulin tended to be lower and the concentration of β-carotene was lower for cows destined to be sick than for cows that were healthy postpartum. At d -1 prepartum, haptoglobin and globulin tended to be greater for cows that were sick postpartum than for healthy cows. The albumin:globulin ratio and creatinine at d -1 tended to be lower for sick cows than for healthy cows. At d 1 postpartum, cows that were sick tended to have greater BHB and had lower Zn, albumin, and retinol than healthy cows. Aspartate aminotransferase tended to be greater for sick cows than for healthy cows. At d 7 (during feed restriction but before diagnosis of clinical ketosis), glucose and cholesterol were lower, and nonesterified fatty acids and BHB were greater, in FR cows than in PID cows. Concentration of Ca tended to be lower for cows in FR and PID than for CON cows. Albumin concentration and the ratio of albumin:globulin were lower for PID cows than for FR cows, whereas haptoglobin was greater for PID than for FR. Paraoxonase was lower for cows in FR and PID than for CON. Activity of γ-glutamyltransferase was greater for cows in FR and PID than for CON cows. Bilirubin tended to be greater for cows in FR and PID compared with CON. Retinol tended to be lower for cows with disorders and lower for PID than FR. β-Carotene was greater for FR cows than for PID cows. The liver functionality index, a measure of cow resilience in the transition period, showed the lowest value in PID and the highest in CON, with FR intermediate. Overall, healthy cows with feed restriction-induced hyperketonemia showed little evidence for involvement of inflammation.