Ovarian Follicular Dynamics, Ovarian Follicular Growth, Oocyte Yield, <italic>In vitro</italic> Embryo Production and Repeated Oocyte Pick Up in Thai Native Heifers Undergoing Superstimulation

Abstract

The objective of this study was to compare the effectiveness of the protocols for superstimulation of follicular growth in Thai native heifers. Heifers (n = 20) were randomly divided into four groups of five heifers/group. Heifers were given a single dose by i.m. administration of 100 mg Follicle Stimulating Hormone dissolved in polyvinylpyrrolidone (FSHp) at 24 h. Ovum pick up (OPU) occurred at 72 h (F24O72 protocol; Group 1) or 96 h (F24O96 protocol; Group 2), and at 36 h and OPU at 72 h (F36O72 protocol; Group 3) or 96 h (F36O96 protocol; Group 4) after follicular ablation. The dynamics of ovarian follicular growth were monitored by twice-daily ultrasonographic examinations. Blood sample collections were performed every 12 h after initiation of treatment for assessment of FSH, E2 and P4 profiles. All heifers were subjected to eight repeated sequential sessions of OPU. The follicular deviation commenced 24±5.32 h after follicular ablation in all groups. The circulatory FSH surged quickly from 24 to 36 h (>0.8 ng/ml) after follicular ablation and circulatory estrogen levels steadily increased from 36 h until OPU in all groups. At the end of the OPU sessions, the mean number of aspirated follicles/heifer/session in F36O72 protocol (Group 3) and F36O96 protocol (Group 4) were higher than in the two other groups (p<0.05). The number of cumulus-oocyte complexes (COCs), cleaved and day 8 blastocysts rates in the F36O72 protocol (Group 3) were higher than in the other groups (p<0.05). It can be concluded that a single dose i.m. administration of 100 mg FSHp at 36 h and OPU at 72 h after follicular ablation (F36O72 protocol; Group 3) was the most effective protocol for superstimulation of follicular growth for repeated OPU and subsequent in vitro embryo production in Thai native heifers.

Intraovarian Injection of Reconstituted Lyophilized Growth-Promoting Factor Extracted from Horse Blood Platelets (L-GFequina) Increases Oocytes Recovery and In Vitro Embryo Production in Holstein Cows

“…By using various schemes of twice-weekly OPU, less than three COCs from non-stimulated cows were aspirated [ 5 ], but more than nine COCs were recovered from cows that had been stimulated with gonadotropin [ 6 ]. Additionally, compared to continuous OPU sessions, which have been shown to affect the rate of oocyte recovery and the estrous cycle by altering the endocrine function and the mechanisms of follicular growth, leading to irregular estrous intervals [ 7 ] or the absence of estrus [ 5 ], OPU sessions repeated at 3-to-4 day intervals produced a higher recovery rate and produced more COCs [ 8 , 9 ]. Therefore, there is still a need for a new OPU protocol that can support the repeated use of donors for the development of a large number of antral follicles and improve in vitro blastocyst development without altering the ovarian structure or its functions.…”

Ovarian responses and FSH profiles at superovulation with a single epidural administration of gonadotropin in the Thai-Holstein crossbreed

“…Follicle stimulating hormone (FSH), exogenous gonadotrophic hormone, is commonly used to stimulate follicular growth, and subsequently obtain a greater number of ovulations, leading to a high number of transferable embryos and a high probability of pregnancy after transfer (Mapletoft, 1986). However, multiple injections of FSH are required due to its short half-life, which is time-consuming and may also be stressful for the cows (Sugano and Shinogi, 1999;Chasombat et al, 2013). Many previous studies proposed solving this issue by administering FSH dissolved in various agents that provide a slow release, such as polyvinylpyrrolidone (PVP) (Yamamoto et al, 1994;Takedomi et al, 1995;Ratsiri et al, 2021) and aluminium hydroxide gel (AH-gel) in cattle (Kimura, 2016).…”

The puerperium in dairy cows: ovarian activity, uterine involution and follicular dynamics

“…A significant number of reports have characterized these wave patterns in the estrous cycle in European cattle breeds (Bos taurus). Borges et al (2001), Viana et al (2010), and Chasombat et al (2013) reported similar types of wave patterns for Holstein-Zebu crossbred heifers and zebu cows (Bos taurus indicus). Further, the data was confirmed by studies conducted by Zeitoun et al (1996) andD'enjoy et al (2012) that evaluated follicular dynamics in Brahman cows (Bos taurus indicus).…”