Associations between circulating levels of natural antibodies, total serum immunoglobulins, and polymorphonuclear leukocyte function in early postpartum dairy cows

How Is Arachidonic Acid Metabolism in the Uterus Connected with the Immune Status of Red Deer Females (Cervus elaphus L.) in Different Reproductive Stages?

Reproductive and condition parameters' dependency on immune status in seasonally reproducing ruminants such as red deer have not been outlined to date. We determined T and B blood lymphocytes; the concentration of IgG, cAMP, haptoglobulin, and 6-keto-PGF1α in blood plasma; and the mRNA and protein expression of PG endoperoxide synthase 2, 5-lipoxygenase, PGE2 synthase (PGES), PGF2α synthase (PGFS), PGI2 synthase (PGIS), leukotriene (LT)A4 hydrolase, and LTC4 synthase (LTC4S) in the uterine endo- and myometrium, on the 4th (N = 7) and 13th (N = 8) days of the estrous cycle, in anestrus (N = 6) and pregnancy (N = 8) in hinds. An increase in CD4+ T regulatory lymphocyte percentage during the estrous cycle and anestrus compared with pregnancy was recorded; the opposite effect was observed for CD21+ B cells (p < 0.05). cAMP and haptoglobin concentration were elevated during the cycle, as was IgG on the fourth day of the cycle, whereas 6-keto-PGF1α concentration was the highest in pregnancy, and the nearest in anestrus similarly were LTC4S, PGES, PGFS, and PGIS protein expression in the endometrium (p < 0.05). We showed an interaction between the immune system activation and AA-metabolite production in the uterus throughout different reproductive stages. IgG, cAMP, haptoglobin, and 6-keto-PGF1α concentrations are valuable candidates for markers of reproductive status in hinds. The results help expand our knowledge of the mechanisms underlying seasonal reproduction in ruminants.

Effect of injectable trace mineral supplementation on peripheral polymorphonuclear leukocyte function, antioxidant enzymes, health, and performance in dairy cows in semi-arid conditions

The objective of this study was to evaluate the effect of subcutaneous injections of 15 mg/mL Cu, 5 mg/mL Se, 60 mg/mL Zn, and 10 mg/mL Mn on health, performance, polymorphonuclear leukocyte (PMNL) function, circulating glutathione peroxidase (GPx) and superoxide dismutase (SOD) concentrations, and inflammation of dairy cows undergoing the transition period in high temperature-humidity index. A total of 923 multiparous cows from 2 commercial dairy farms were randomly allocated into 1 of 2 treatment groups as follows: control and injectable trace mineral supplementation (ITMS). Cows in the ITMS group received 7 mL of subcutaneous injections at dry-off (208 ± 3 d of gestation), 260 ± 3 d of gestation, and at 35 ± 3 d in milk (DIM). Data regarding health traits, reproductive performance, milk yield, and survivability were extracted from farm database software, and animals were followed-up until 300 DIM. For a subset of 142 cows from one herd, blood samples were collected at enrollment, and at 3 ± 1, 7 ± 1, 10 ± 1, and 35 ± 3 DIM to evaluate hematology, PMNL function, GPx and SOD concentrations, and circulating haptoglobin. Logistic regression was used to assess health and pregnancy per artificial insemination at first service. Cox proportional hazards models were used to evaluate hazard of pregnancy and culling. Mixed linear regression models accounting for repeated measures were used to assess all continuous variables collected over time. Parity, twinning, and previous gestation length were considered as potential confounders. Farm was included as a random effect. The ITMS cows tended to have lower incidence of metritis and stillbirth compared with control group. However, ITMS treatment did not influence the incidence of other diseases (e.g., mastitis, retained placenta), milk yield, reproductive performance, culling, and leukocyte count. Neutrophil-to-lymphocyte ratio, PMNL phagocytosis, and oxidative burst as well as intensity of the oxidative burst were greater for ITMS-treated cows in comparison to control cows. The ITMS cows had decreased expression of the adhesion molecule L-selectin on PMNL surface. The serum concentration of GPx and SOD were not affected by ITMS treatment. In conclusion, ITMS tended to reduce the incidence of metritis and stillbirth parturition, improved PMNL function, and improved the inflammatory status of dairy cows undergoing the transition period in high temperature-humidity index conditions. However, these findings did not translate into improved milk yield, reproductive performance, and survivability.