Circulating metabolic biomarkers and hormones and their relationships at different pre- and post-parturition periods of Ghezel ewes

Information regarding metabolic profile in different physiological periods of ewes can assist veterinarians to monitor the herd health and productive performance. Furthermore, the relationships among the metabolic parameters can be used to detect the effect of each parameter on another one. Five clinically healthy adult Ghezel ewes were selected at 4 weeks before parturition and evaluated at 4 and 2 weeks before, 2 and 4 weeks and 2, 3 and 4 months after parturition. Blood samplings were performed from each animal at the above mentioned periods, in the meantime, serum concentrations of glucose, BHBA, NEFA, cholesterol, TG, HDL, LDL, VLDL, insulin, T3, T4, prolactin, cortisol and IGF-1 were measured in all specimens. In all studied periods, glucose was negatively correlated with Insulin, BHBA, and NEFA. The positive significant correlation was detected between glucose and cortisol. BHBA had a positive and significant correlation with NEFA in all ewes. BHBA and NEFA were significantly correlated, negatively and positively, with insulin and cortisol, respectively. Cortisol had both significant and positive relationships with TG, cholesterol, HDL, LDL, and VLDL. Insulin had significant negative and positive correlations with cortisol and both IGF-1 and prolactin, respectively.  Moreover, there was a negative significant correlation between cortisol, IGF-1 and prolactin in all ewes. Significant positively relationship was detected between IGF-1, and prolactin at all groups. T3 and T4 were significantly positive related together. Information regarding the correlations among circulating metabolic parameters can be used to estimate the changing patterns of each metabolic parameter via evaluating the others.