Screening of Some Changes in Hematological, Serum Biochemical, Inflammatory and Oxidative Parameters Associated with Pathogenesis of Retained Placenta in Holstein Dairy Heifers

Retained placenta is still one of the major problems facing dairy farms, and up until now, haematological and biochemical changes related to the condition of retained placenta have been mysterious. Our study aimed to screen the presumptive serum biochemical and haematological alterations in relation to the pathogenesis of retained placenta in dairy Holstein heifers. Twenty heifers were used in this study; ten of them suffered from retained placenta, and the others were kept under control as they expelled their placenta within the reference time range after parturition. Concerning serum biochemical changes, heifers affected by retained placenta suffered from disturbances in the redox state and exhaustion of enzymatic and non-enzymatic antioxidants. In addition, the serum concentration of anti-inflammatory interleukin-13 was increased in association with an elevated level of serum mucin-1, C-reactive protein and alpha-1 anti-trypsin in these heifers. Also, retained placenta induced a decrement in the serum levels of inteleukin-8 (IL-8), prostaglandin F-2 alpha (PGF-2α) and an increment in the serum level of prostaglandin-E2 (PGE-2). Moreover, serum concentrations of non-esterified fatty acids (NEFA) and creatine kinase enzyme activity were elevated in heifers with retained placentas. Haematological results did not show any significant change in RBCs count, haemoglobin concentration, hematocrit%, or platelet count between the two groups. Controversially, the total leukocytic count, granulocytes, lymphocytes and monocytes counts were elevated in cows with retained placentas. In conclusion, the retained placenta condition is accompanied by oxidative stress and inflammatory disturbances that directly affect the metabolic and hormonal states of dairy heifers.