Alterations in cortisol concentrations and expression of certain genes associated with neutrophil functions in cows developing retention of fetal membranes.

Elevated cortisol concentrations have been reported to impair the functions and alter the life span of neutrophils in cows. The present study assessed the cortisol concentrations and expression of few genes related to longevity (Fas, Caspase 3, Bcl2) and margination (CD 62L, CD 18/11b) of neutrophils in relation to retention of fetal membranes (RFM) in dairy cows. Cortisol concentrations were significantly higher on the day of calving and day 2 postpartum in RFM cows than normal cows. Expression of CD 62L was significantly lower on the day of calving and day 2 postpartum in RFM cows than normal cows. While expression of Fas and GR was significantly lower on the day of calving, expression of Bcl2 was lower on day 7±2 pre-partum in RFM cows compared to normal cows. No significant difference was observed in the expression of CD 18/11b and Caspase 3 between RFM and normal cows. Cortisol concentration was negatively correlated with expression of GR, Fas, CD 62L, CD18/CD11b and Caspase 3, while positively correlated with immature neutrophil percentage and expression of Bcl2. It may be inferred that cortisol concentrations and expression of certain genes associated with lifespan and margination of neutrophils were altered in cows developing RFM compared to those expelled the fetal membranes normally.

Alteration in peripheral blood concentration of certain pro-inflammatory cytokines in cows developing retention of fetal membranes.

Retention of fetal membranes (RFM) adversely affects the production and reproduction potential of the affected cows leading to huge economic loss. Physiological separation of fetal membranes is reported to be an inflammatory process. The present study compared the concentrations of certain pro inflammatory cytokines [Interleukin 1ß (IL-1), Interleukin 6 (IL-6), Interleukin 8 (IL-8) and Tumor necrosis factor α (TNF-α) between the cows that developed RFM (n=10) and the cows that expelled fetal membranes normally (n=10) to find out if they could serve as a predictive tool for RFM. Blood samples were collected from the cows from 30 days before expected parturition through day -21, day -14, day -7, day -5, day -3, day -1, on the day of parturition (day 0), day 1 postpartum and the pro-inflammatory cytokines were estimated in blood plasma by ELISA method. The IL-1ß concentration was significantly lower (P<0.05) in cows that developed RFM compared to those that expelled fetal membranes normally from 3 days before calving till the day of calving. The plasma concentrations of IL-6 and IL-8 were also lower (P<0.05) in cows that developed RFM than those calved normally. On the day of calving, significantly (P<0.05) lower concentrations of TNF-α was observed in cows that developed RFM compared to those expelled fetal membranes normally. It may be inferred that the concentrations of IL-1, IL-6, IL-8 and TNF-α around parturition were altered in cows developing RFM compared to those expelled fetal membranes normally.

Risk factors and impact of retained fetal membranes on performance of dairy bovines reared under subtropical conditions.

The risk factors and impact of retained fetal membranes (RFM) on productive and reproductive performance of crossbred cattle, Zebu cattle, and Murrah buffalos were evaluated using data spread over 12 years. Multivariable logistic regression model was used to identify risk factors and to quantify their odds ratio (OR). Overall incidence of RFM in crossbred cattle, Zebu cattle, and Murrah buffalos were 26, 16, and 13 %, respectively; and significant risk factors for RFM in crossbred cattle were abortion (OR = 3.9), dead calf (OR = 4.1), dystocia (OR = 4.3), pluriparity (OR = 1.5), and shorter gestation length (OR = 4.3). In Zebu cattle, abortion (OR = 4.0), dead calf (OR = 3.7), dystocia (OR = 3.9), lower birth weight of calf (OR = 1.6), and shorter gestation length (OR = 6.4) were significant risk factors for RFM. In Murrah buffalos, abortion (OR = 19.2), dead calf (OR = 4.4), dystocia (OR = 4.7), pluriparity (OR = 1.7), shorter gestation length (OR = 12.7), and calving during summer season (OR = 1.8) were the risk factors for RFM. Although the occurrence of RFM did not affect fertility parameters, a significant (P < 0.05) decrease in 305-day milk yield and total milk yield was observed in RFM-affected crossbred cattle. Taken together, it may be concluded that increased parity, abnormal calving, and short gestation length were the main risk factors for RFM in dairy bovine.