Progesterone and pregnancy status of buffaloes treated with a GNRH agonist

Estrus synchronization and Fixed Time Artificial Insemination (FTAI) in dairy buffaloes during seasonal anestrus

“…It has reported that the DF in female buffaloes could ovulate when the diameter was around 5-8 mm (Baruselli et al 1997), which corroborated the results observed in this study with the DF diameters reaching averages between 7.9 and 8.9 mm. These results were also similar to results previously reported (Campanile et al 2007;Campanile et al 2008) of follicles with diameters from 4.2 to 13.0 mm, when ovulation was induced with hCG ,or GnRH agonist. On D16, 48.5% of the animals presented DF in both the groups, indicating that the protocols used for estrus synchronization showed satisfactory efficiency rates.…”

Impact of buserelin acetate or hCG administration on day 5 post-ovulation on subsequent luteal profile and conception rate in Murrah buffalo (Bubalus bubalis)

“…In contrast, GnRH treatment on day 5 post-estrus failed to increase plasma progesterone in cows (Sterry et al, 2006). In buffalo, treated with buserelin acetate (12 µg; Campanile et al, 2007Campanile et al, , 2008b or hCG (1500 IU; Campanile et al, 2007) on day 5 after AI, there was an increase in milk whey progesterone on day 15. Nevertheless, in the current study the increased dose rate of buserelin acetate (20 µg) had a positive impact on plasma progesterone concentrations.…”

“…In cattle, earlier studies have also observed an increase in conception rate (5%-45%) subsequent to administration of either GnRH analogue or hCG on day 5 post-AI (Arnett et al, 2002;Santos et al, 2001;Willard et al, 2003), whereas others have failed to show any beneficial impact (Dahlen et al, 2010;Stevenson et al, 2007). Nevertheless, Campanile et al (2008b) found that there was a positive impact of buserelin acetate (12 µg) administration on pregnancy rates in buffalo mated during periods of increasing daylight. Moreover, buffalo treated with buserelin acetate (12 µg) or hCG (1500 IU) on day 5 post-AI, failed to increase the conception rate (Campanile et al, 2007).…”

“…Administration of hCG or GnRH agonists induces an acute release of LH in cattle (Endo et al, 2013) and buffalo (Rastegarnia et al, 2004). The concentrations of plasma LH and FSH following treatment with gonadotropins are greater than concentrations associated with the pre-ovulatory gonadotropin surge and this may be responsible for the ovulation from a dominant follicle present during the luteal phase of estrous cycle (Campanile et al, 2008b). Furthermore, on day 5 post-ovulation the diameter of the dominant follicle from which ovulation occurred was larger than dominant follicles from which there was no ovulation in both treatment groups.…”

“…The opportunity to suppress luteolytic mechanisms through hormonal approaches before the maternal recognition of pregnancy is a possible strategy for improving the conception rate in dairy animals. To prevent luteal deficiency induced early embryonic mortality, administration of gonadotropin releasing hormone (GnRH; Campanile et al, 2008b;Rastegarnia et al, 2004), human chorionic gonadotropin (hCG; Campanile et al, 2007;Marques et al, 2002) and progesterone (Pandey et al, 2013a) was used in cattle and buffalo. The mid-luteal phase GnRH administration improves luteal functions and luteinizes developing follicles to suppress the circulating estradiol (Thatcher et al, 2003).…”