Do the blood anti-Müllerian hormone concentrations in young females correlate with the ovarian follicular population later in life in water buffalo?

In this longitudinal study, the anti-Müllerian hormone (AMH) levels in blood were determined in 32 Murrah buffalo females at 8, 10, 12, 16 and 19 months of age when females were synchronized and the antral follicular population (AFP) was estimated. Correlations of AFP to the AMH level at 19 months of age and retrospectively to younger ages were investigated. Then females were split into high and low AFP, and their AMH levels were compared for all ages and tested as predictors of AFP categories. The highest AMH level (p < .05) was detected at 8 months, reducing but not differing (p > .05) at 10, 12 and 16 months then reducing again (p < .05) at 19 months of age. The mean AFP was 17.6 ± 6.3 follicles, and it was positively correlated with AMH in all ages tested. High AFP females had approximately two times more antral follicles than low AFP (p < .05) and their AMH levels were higher (p < .01) than in low AFP ones in all ages. Only at 8 months, AMH levels can be used to precociously detect high AFP heifers (a cut-off point of 464.7 pg/mL; p < .05), while low AFP heifers could be detected by AMH measurements at 8, 10, 12 and 16 months of age (p < .05). We conclude that AMH of buffalo calves correlates with AFP of heifers later in life and depending on the age, its levels could be used to identify future females with low or high AFP.

Fertilization with follicular fluid reduces HSP70 and BAX expression on bovine in vitro embryos

The in vivo fertilization process occurs in the presence of follicular fluid (FF). The aim of this study was to evaluate the effect of in vitro fertilization medium supplementation with 5% or 10% bovine follicular fluid (BFF) on the production of in vitro bovine embryos. FF was collected from ovarian follicles with a diameter of 8-10 mm, and cumulus-oocyte complexes (COCs) were co-incubated with sperm for 24 h in the commercial medium BotuFIV® (BotuPharma©), being distributed among the experimental groups: oocytes fertilized in a control medium; oocytes fertilized in a medium supplemented with 5% BFF; and oocytes fertilized in a medium supplemented with 10% BFF. After fertilization, the zygotes were cultured in vitro for 8 days. Embryo development was assessed through cleavage rates (day 2) and blastocyst formation rates (day 8). The relative expression of the genes OCT4, IFNT2, BAX, HSP70 and SOD2 was measured using the real-time polymerase chain reaction method. There was no difference (p > .05) among the different experimental groups in terms of cleavage rates and blastocyst formation rates. Regarding the gene expression results, only the blastocysts from oocytes fertilized with 10% BFF showed significantly lower expression of IFNT2 (p = .003) and SOD2 (p = .01) genes compared to blastocysts from oocytes fertilized in control medium alone, while there was no difference between blastocyst from oocytes fertilized in control medium and the ones from oocytes fertilized with 5% BFF. In addition to this, the blastocysts from oocytes fertilized with 5% BFF showed significantly reduced levels of expression of the heat shock protein HSP70 (p < .001) and the pro-apoptotic protein BAX (p = .015) compared to blastocysts from oocytes fertilized with control medium. This may indicate that lower supplementation of BFF to the IVF medium creates a more suitable environment for fertilization and is less stressful for the zygote.