Produção in vitro de embriões bovinos utilizando diluidor com adição de insulina ou fator de crescimento semelhante à insulina tipo 1 (IGF-1)

Abstract

The in vitro production of bovine embryos has low embryonic development rates compared to production in vivo. In order to evaluate the effect on in vitro bovine embryo was added Insulin and / or growth factor insulin-like type-1 (IGF-1) to semen extender. Ovaries were aspirated from slaughterhouse and only selected cumulus oocyte complexes (COCs) grade I, II and III, and then incubated for 24 hours at 38.8 ° C and 5% CO2. After maturation, a semen straw from each treatment (control, insulin, IGF-1 and insulin + IGF-1) was thawed and placed in a Percoll gradient for removal of intrauterine insemination. The gametes were co-incubated 18 to 22 hours and then cultured for seven days. After 48 hours, the cleavage rate was assessed (D2), and seven days after blastocyst (D7). 679 ovaries were aspirated, 671 oocytes recovered grade I, grade II 329 and 152 grade III, over six repetitions. There was no significant difference for the cleavage rates. Treatment Control showed higher embryo development rates. Treatment with insulin resulted in higher production of morulae (47.7%). Treatment with IGF-1 and insulin + IGF-1 had higher rates for the early blastocyst stage. The control treatment resulted in larger expanded blastocyst rates (51.0%). There was no statistically difference (P> 0.05) for quality grade I. Treatment with IGF-1 showed the highest rates (35.3%) for the quality grade II. For the quality grade III treatment with insulin (46.4%) was higher. Treatment Control showed lower degenerate rate (45.1%) and higher rate of unfertilized (54.9%). Therefore we can conclude that the addition of insulin and / or IGF-1 to the semen extender did not increase cleavage rates and blastocyst embryos produced in vitro, not improving embryo quality.