Effects of flaxseed supplementation on endometrial expression of ISG17 and intrauterine prostaglandin concentrations in primiparous dairy cows submitted to GnRH-based synchronized ovulation

Abstract

The objective of the experiment was to determine the effects of feeding whole flaxseed on ovarian function and uterine concentration of prostaglandins on the 17th day post-ovulation. Forty-eight primiparous Holstein cows averaging 550 kg of body weight (BW) were allotted at 2 wk postpartum to two groups of 24 animals: a control diet with no added fat (CON) or a diet with 9% whole flaxseed (FLA). At 6 wk postpartum cows were subjected to a Presynch-Ovsynch protocol with and without artificial insemination on day 0. Real-time transrectal ultrasonography and plasma progesterone concentrations were used to evaluate ovarian function. On day 17, uterine flushings and biopsies of uterine endometrium were collected. Synchronized ovulation rates based on low and high plasma progesterone concentrations on days 0 and 7, respectively, were the same for cows fed CON and those fed FLA (87.5 vs. 87.5%). The 13,14-dihydro-15-keto- PGF2a (PGFM) to prostaglandin E metabolite (PGEM) ratio in uterine flush was significantly higher for non-inseminated cows fed CON (32.0) than for non-inseminated cows fed FLA (17.5) and there was no difference between pregnant cows fed CON (12.2) and those fed FLA (12.0). Feeding flaxseed before breeding may contribute to increased fertility by improving uterine conditions for embryo survival.