Mastitis in the transition period: identification of potential blood markers

Brief Research Report: Expression of PD-1 and CTLA-4 in T Lymphocytes and Their Relationship With the Periparturient Period and the Endometrial Cytology of Dairy Cows During the Postpartum Period

The present study sought to evaluate the expression of PD-1 and CTLA-4 in blood T lymphocytes during the periparturient period and their relationship with uterine health in dairy cows, as determined by endometrial cytology and serum concentrations of β-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFAs), which are indicators of a negative energy balance. The second objective of this study was to investigate whether the expression of PD-1 and CTLA-4 in T lymphocytes is associated with the serum acute phase-protein haptoglobin concentration during the periparturient period. To address these objectives, 26 clinically healthy dairy cows were used. Peripheral blood was collected 14 days prepartum (T-14), at calving (T0), and 30 days postpartum (T30) to measure the expression of PD-1 and CTLA-4 in blood T lymphocytes by flow cytometry. In addition, we collected blood at T0, 10 days after parturition (T10), and T30 to obtain serum and determine the serum concentrations of NEFA, BHB, and Hp. Endometrial cytology was performed at T10, 20 days after parturition (T20), and T30. In the present study, we observed higher expression of CTLA-4 and PD-1 in T lymphocytes at parturition and in the prepartum period, which could indicate a relationship between these immune checkpoints and immunological tolerance during gestation in dairy cattle. In addition, a negative association between the expression of these immune checkpoints prepartum or at parturition and endometrial cytology at T20 and T30 was observed, indicating the negative implications of these immune response regulators in susceptibility to infections. This finding was further corroborated by the relationship between the serum concentration of haptoglobin and the expression of CTLA-4 and PD-1 by T lymphocytes. However, we did not observe a relationship between the indicators of negative energy balance, evaluated by the serum concentrations of BHB and NEFA, and the expression of the immune checkpoint markers studied. Thus, our findings represent an initial step that paves the way for the development of new therapeutic alternatives directed by the host with the objective of increasing the resistance of dairy cattle to infections in this critical period of life.

Changes in antioxidant enzyme activities and metabolic parameters in dairy cows during different reproductive periods

Our study aimed to monitor the alterations in antioxidant enzyme activities and the metabolic profile parameters and their relationships in dairy cows during different reproductive stages (gestational-, dry-, pre- and post-partum). The collection of blood samples from thirty healthy pregnant Holstein cows took place at a commercial dairy farm, between September 2015 and June 2016. The cows covered eight different reproductive stages (4-6 weeks before the dry period (D4-6w)), at the beginning of the dry period (D0; on day 210 of gestation), the first month of the dry period (D1m), antepartum day 8 (APd8), postpartum (PP) day 3 (PPd3), PP day 8 (PPd8), PP between 3rd-4th weeks (PP3-4w) and PP between 80 and 90 days (PP80-90d). The activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were analysed to monitor and evaluate the antioxidant system. Concentrations of beta-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA), albumin, glucose, total bilirubin, cholesterol, calcium (Ca) and the enzyme activities of aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), gamma-glutamyl transferase (GGT) were also determined as metabolic profile parameters. GPx activities increased in D1m (P < 0.05) and peaked during the PP3d and PP8d periods (P < 0.0001), with values decreasing again at the PP3-4w period. The most significant change in SOD activities was detected in the PP3-4w with a significant decrease (P < 0.05). BHBA and NEFA concentrations increased significantly during the PPd3 and PPd8 periods (P < 0.05), with BHBA decreased to low values in the PP3-4w (P < 0.05). Significant positive correlations were found between BHBA, NEFA, total bilirubin and GPx (0.784, 0.874 and 0.871; P < 0.05, P < 0.01 and P < 0.01 respectively). A significant negative correlation between calcium and cholesterol and GPx was found (-0.857, P < 0.01; and -0.681, P < 0.05, respectively). As a result, a relationship was determined between blood antioxidant enzymes and metabolic parameters at different periods. High GPx and SOD activities, especially in the early period before and after parturition, is thought to be related to the adaptation of the animals to this process. The lack of adaptation abilities of animals during these periods causes many problems seen during early postpartum. Therefore, considering GPx and SOD activity measurements in pre- and postpartum periods contributes to better management of these periods and the prevention of complications.

Effect of mastitis on some hematological and biochemical parameters of Red Sokoto goats

AIM

This research project investigates the effect of mastitis on some hematological and biochemical parameters of Red Sokoto goats (RSGs).

MATERIALS AND METHODS

In this investigation, 16 clinically and subclinically diagnosed mastitic and 20 non-mastitic RSGs, within Sokoto metropolis, were sampled. Blood samples were collected both in ethylenediaminetetraacetic acid and anticoagulant free sample bottles for hematology and biochemical analysis, respectively.

RESULTS

A statistical analysis of the results revealed no significant difference in all the hematological parameters analyzed for both the mastitic and non-mastitic goats except mean corpuscular hemoglobin where significant difference (p<0.05) was observed. Similarly, no significant difference was recorded in the serum biochemistry except for the increase in total protein (p<0.001), globulin (p<0.05), and alanine aminotransferase activity (p<0.05).

CONCLUSION

This finding is a pointer to the fact that mastitis could be regarded as a localized problem affecting the udder without serious systemic or metabolic involvement in RSGs.