Cow-calf relationships of endocrine and metabolic parameters immediately after parturition.

In addition to the metabolic and health status of cows at parturition, intrauterine conditions, the calving process, and colostrum feeding may affect endocrine and metabolic pathways in the neonate. Forty-six clinically healthy cows without dystocia were enrolled, along with their calves . Blood samples were collected from cows (4 h postpartum [p.p.]) and calves (4, 12, and 24 h p.p.). Calves were fed colostrum from their dams immediately after blood sampling at 4 and 12 h p.p. Concentrations of glucose, insulin, nonesterified fatty acids (NEFA), IGF-1, and prolactin (PRL), as well as activities of aspartate-aminotransferase and gamma-glutamyltransferase were measured in the plasma of cows. In calves, we measured various endocrine and metabolic parameters related to protein, glucose, and lipid metabolism (e.g., NEFA, phospholipids [PL], total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C]), IgG, glucose, glucagon, and insulin. Pearson correlation coefficients among parameters measured in cows and calves were calculated. At 4 h p.p. (i.e., before colostrum feeding), maternal glucose was positively correlated with glucose (r = 0.29) and NEFA in calves (r = 0.25). Plasma NEFA in dams was negatively correlated with fat metabolism (PL: r = -0.31, HDL-C: r = -0.32) and plasma IgG (r = -0.28) in calves at 4 h p.p. Positive correlations were identified between the glucose of dams and calves (12 h p.p.: r = 0.26; 24 h p.p.: r = 0.45). Maternal NEFA was positively associated with calf lipid metabolism at 24 h p.p. (PL: r = 0.44, TC: r = 0.39, LDL-C: r = 0.37, HDL-C: r = 0.36). Primarily positive and significant correlations were detected between maternal PRL and lipid metabolism-related parameters in calves (NEFA at 12 h p.p.: r = 0.26, PL at 12 h p.p.: r = 0.31; PL at 24 h p.p.: r = 0.57, TC at 24 h p.p.: r = 0.62, LDL-C at 24 h p.p.: r = 0.48, and HDL-C at 24 h p.p.: r = 0.69). In conclusion, the metabolic status of neonates is partly associated with the metabolism of their mothers before the first feeding, whereas later associations between cow and calf are likely due to colostrum feeding.