Metabolic, adipokine (irisin, spexin, visfatin), and ER stress (GRP78) responses in multiparous Brown Swiss cows: a multivariate approach across physiological stages and body condition scores

This study investigated the responses of novel adipokines (irisin, spexin, visfatin), an endoplasmic reticulum (ER) stress marker (GRP78), and traditional metabolic parameters (non-esterified fatty acids (NEFAs), beta-hydroxybutyrate (BHBA), urea, albumin, globulin, total cholesterol) in 360 healthy Brown Swiss dairy cattle. The animals were categorized into 18 subgroups based on pregnancy stages (early, mid, dry), lactation stages (early, mid, late), and body condition scores (BCSs). Serum analyses were performed using ELISA and spectrophotometric methods. Interactions between physiological stages and BCS were highly significant for all measured parameters (p<0.001). Results showed that mean serum levels of spexin (ranging from 14.02 to 36.04 pg mL−1) and irisin increased as pregnancy and lactation progressed. Visfatin levels exhibited a significant increase specifically during the gestation period, peaking during the dry period (24.09 ng mL−1), and maintained a significant increasing trend as lactation progressed toward the late stage (Tables 2, 4). Conversely, GRP78 (peaking at 0.46 ng mL−1), NEFA (peaking at 0.52 mmol L−1), and urea levels peaked during the dry period and early lactation, subsequently decreasing as metabolic stability was achieved. Notably, during the dry period, stress markers rose despite declining albumin and globulin levels (p<0.05). These data indicate that the dry period and early lactation are the most critical phases for metabolic and cellular stress, characterized by lower spexin and elevated GRP78 and NEFA concentrations. The later rise in irisin and visfatin, while BHBA remained within physiological limits, confirms successful metabolic adaptation (p<0.001). In conclusion, the integrated evaluation of these novel biomarkers is anticipated to provide significant contributions to protective strategies and metabolic management in dairy cattle.