Inflammatory status and its relationships with different patterns of postpartum luteal activity and reproductive performance in early lactating Holstein cows.

This study was undertaken to determine the effect of inflammatory status on different patterns of postpartum luteal activity and reproductive performance of Holstein cows during early lactation. The cows (n = 75) averaged 3.4 ±â€¯1.2 (mean ±â€¯SEM) in parity and 3.1 ±â€¯0.2 (mean ±â€¯SEM) in body condition score at calving. Transrectal ultrasonography was performed twice weekly from day 10-60 postpartum to consider ovarian dynamics. Plasma concentrations of progesterone (P4) and estradiol (E2) were measured twice weekly and plasma levels of tumor necrosis factor alpha (TNF-α) and lipopolysacchride binding protein (LBP) were measured weekly (week 3-6 postpartum). Based on plasma P4 and E2 results, 34 (45.3%) cows had normal luteal activity (NLA), whereas 19 (25.3%), 12 (16.0%), 7 (9.3%) and 3 (4.0%) cows had prolonged luteal phase (PLP), delayed first ovulation (DO), anovulation (AO) and short luteal phase (SLP), respectively. Plasma TNF-α and LBP concentrations were affected by postpartum luteal activity (NLA, SLP and PLP), ovulatory status (DO and AO) and number of weeks postpartum (P < .05). These concentrations were greater in cows with PLP (P < .05) as compared to NLA cows, and in cows that had delayed ovulation or anovulation compared to ovulated cows (P < .05). Cows with PLP had greater open days and lower conception rate as compared to NLA cows (P < .05). Healthy cows had a larger CL and greater plasma estradiol and progesterone concentrations at first and second cycle postpartum compared to inflamed cows and followed it with greater fertility (P < .05). In conclusion, inflammatory statuses were different in high-producing dairy cows showing PLP, AO and DO in comparison with the postpartum normal luteal activity (NLA) cows that influenced reproduction outcomes.

Dietary conjugated linoleic acid supplementation alters the expression of genes involved in the endocannabinoid system in the bovine endometrium and increases plasma progesterone concentrations.

Endocannabinoids are derived from phospholipids and reduce fertility by interfering with implantation. Identification of changes in the expression of genes of the endocannabinoid system as a result of dietary inclusion of conjugated linoleic acid (CLA) is critical to the advancement of our understanding of the nutritional regulation of uterine function. An experiment was conducted on transition cows to evaluate the expression of key endocannabinoid genes in bovine endometrium in response to dietary supplementation with CLA. A total of 16 cows were randomly assigned to two treatments: (1) control (75 g/day palm oil) and (2) CLA (75 g/day CLA) from 21 days prepartum to Day 42 postpartum. Cows underwent uterine biopsy on days 21 and 42 postpartum. The abundance of mRNA encoding endocannabinoid receptor (CNR2), N-acyl phosphatidylethanolamine phospholipase D (NAPEPLD), fatty acid amide hydrolase (FAAH), N-acylethanolamine acid amidase (NAAA), and monoglyceride lipase (MGLL) was measured by real-time PCR. Results reported that relative levels of mRNA encoding CNR2 and NAPEPLD were decreased (P < 0.05) compared with control cows between Days 21 and 42 postpartum. Relative levels of mRNA coding for NAAA and MGLL were not different (P > 0.05) in the same situation. Mean plasma progesterone concentrations were higher in CLA-fed cows compared with control cows at Day 42 postpartum (3.51 and 1.42 ng/mL, respectively, P < 0.05). In conclusion, we suggest that the beneficial effects of a diet enriched with CLA are the result of a decrease in relative gene expression of the endocannabinoid receptor (CNR2) and enzymes that synthesize fatty acid amides (NAPEPLD) and of an increase in the expression of PTGS2 that in turn can oxidate endocannabinoids and consequently resulted in increased plasma progesterone concentrations during early lactation.