Induction of subclinical ruminal acidosis leads to marked alterations in blood immunometabolic markers and minerals in lactating Jersey than Holstein cows file in response to

Subacute ruminal acidosis (SARA) has long been regarded as a major reason for economic losses in the dairy industry in the United States. SARA has been associated with decreased milk production and decreased efficiency of milk production, while it increases culling rate and death loss. Although Holstein and Jersey cows have inherent differences in terms of lactation potential their response to SARA in terms of immunometabolic alterations and their resilience to normal levels after induction of SARA are yet to be defined. Twelve lactating cows (>100 DIM; n = 12/breed) were used in a replicated 2 × 2 Latin square design of represented period and dietary treatment (control and challenge). Each period comprised 10 d divided into 4 stages: baseline (d 1–3), feed restriction (d 4), challenge (d 5), and recovery (d 6–10). In each period a control (CO) diet was offered during baseline and recovery stages. On d 4 cows were restricted to 50% of average baseline feed intake until d 5. The challenge on d 5 consisted of either a CO diet or the CO + 4.6 kg of a 50:50 wheat/barley pellet. Blood samples were collected on d 5 at 0, 3, 6, and 12 h relative to the challenge. Data from cows subjected to challenge were analyzed using the PROC MIXED procedure of SAS, where square, period, breed (b), and h were fixed effects, while cow nested within period was the random effect. An interaction of b × h (P < 0.04) was observed for Mg, Na, K, aspartate transaminase (AST), NEFA, and BHBA with Jerseys having greater concentrations of these biomarkers at either 3 or 6 h after challenge. Besides NEFA and Mg, Jerseys also had greater concentrations of other biomarkers at 0 h. Concentrations of Mg, ceruloplasmin, albumin, alkaline phosphate, haptoglobin, NEFA, and reactive oxygen metabolites (ROMt) were greater (P < 0.04) overall in Jersey cows regardless of h after challenge. Similarly, creatinine and myeloperoxidase were greater (P < 0.03) in Holstein cows. Overall, our results suggest that the profile of immunometabolic biomarkers and minerals in blood were more affected by SARA in Jerseys.