Effects of blood ²-hydroxybutyric acid levels on the response to Ovsynch in primiparous cows

Abstract

The aim of this study was to investigate the effects of low and moderate blood β-hydroxybutyric acid (BHBA) levels in primiparous cows during the early postpartum period on follicle development and pregnancy rate after the Ovsynch protocol. Holstein primiparous cows with low (n = 85) and moderate (n = 71) BHBA concentrations were used as experimental animals. At 7-8 weeks postpartum, blood samples were collected and the Ovsynch protocol was performed on the same day. Ultrasonographic examination was performed to determine the dominant follicle (DF) diameter and presence of corpus luteum on the day of the first and second gonadotropin releasing hormone (GnRH1 and GnRH2) injections and prostaglandin F2 alpha (PGF2α) injection as well as 24 and 48 h after the GnRH1 and PGF2α injections. The ovulatory response to GnRH1 and pregnancy rate at day 30 and day 60 postinsemination were also evaluated. No significant differences were observed between groups in the DF diameter on the day of GnRH1 and PGF2α injections, and at 24 and 48 h after these injections, as well as in the ovulation and atresia response to GnRH1 (P > 0.05). Significant differences were observed between groups in DF diameter (low-BHBA group, 13.8 ± 0.2 mm; moderate-BHBA group, 13.2 ± 0.2 mm; P = 0.039) at the time of insemination, and in pregnancy rates at 30 days (low-BHBA group, 38.82%; moderate-BHBA group, 21.13%, P = 0.017) and 60 days after insemination (37.6 and 18.3%, respectively; P = 0.008). Our findings suggest that moderate blood levels of BHBA (0.80-1.19 mmol/L) in primiparous cows during the early postpartum period affect the response to the Ovsynch protocol.

The Dynamic Transcription Profiles of Proliferating Bovine Ovarian Granulosa When Exposed to Increased Levels of β-Hydroxybutyric Acid

“…Hence, low doses of BHBA have been shown to exert positive effects in the treatment of certain diseases (33,34). However, if the concentration of BHBA increases excessively, this could directly or indirectly affect normal liver metabolism (35,36) and reproductive performance (e.g., granulosa cell development and oocyte maturation) (20,37,38) in ruminants such as cows.…”

The Association between Blood Β-Hydroxybutyric Acid Concentration in the Second Week of Lactation and Reproduction Performance of Lithuanian Black and White Cows

“…Moderate blood BHB levels during the early postpartum period affect response to the hormonal estrus synchronization protocol [ 10 ]. Postpartum return to estrus is associated with high concentration of estradiol and low concentration of BHB in early lactation [ 11 ]. In addition, other factors, such as the season of calving, breed, and management, should be considered for diagnosis of HYK in dairy cattle [ 12 ].…”