SummaryThe aim of the current study was to investigate the effect of caffeine supplementation during in vitro maturation (IVM) for different maturation times on the developmental potential of canine oocytes recovered from ovariohysterectomized bitches. The recovered cumulus-oocytes complexes were in vitro matured for 72 h. Here, 10 mM caffeine was added to the maturation medium for different incubation times (caffeine from 0-72 h maturation, caffeine for the first 24 h of maturation only, caffeine addition from 24 to 48 h maturation time, caffeine addition from 48 to 72 h maturation or in caffeine-free medium, control group). The matured oocytes were in vitro fertilized using frozen-thawed spermatozoa. The presumptive zygotes were in vitro cultured in synthetic oviductal fluid medium for 5 days. The results showed that both maturation and fertilization rates were significantly higher (P ˂ 0.05) using caffeine-treated medium for the first 24 h of maturation compared with the control and other two groups of caffeine treatment (from 24 to 48 h and from 48 to 72 h), whereas use of caffeine-treated medium for a 0-72 h incubation time did not affect these rates (P > 0.05). Interestingly, the matured oocytes in caffeine-supplemented medium for the first 24 h or from 0-72 h showed a significant (P ˂ 0.05) increase in the total number of cleaved embryos compared with the control group. In conclusion, supplementation of the maturation medium with 10 mM caffeine for the first 24 h of maturation or during the whole maturation time (0-72 h) improved nuclear maturation and subsequent embryo development preimplantation following in vitro fertilization.
Keywords: Caffeine; Canine oocytes; IVC; IVF; IVM.