No abstract

The present study was designed to investigate the effects of amino acid addition (histidine and L-tyrosine) to the oocyte maturation medium on in vitro maturation (IVM), in vitro fertilisation (IVF), cleavage (CR) rates, and in vitro embryonic cultivation (IVC; Morulla and Blastocyst stage) in buffaloes. Histidine (0.5, 1, and 3 mg/ml) or L-Tyrosine (1, 5, and 10 mg/ml) were added to the synthetic oviductal fluid (SOF) and Ferticult media. Within two hours, the ovaries were collected and transported to the lab. Follicles with a diameter of 3 to 8 mm were aspirated to recover the cumulus oocyte complexes (COCs). The IVM, IVF, CR, and IVC (Morulla and Blastocyst) rates were evaluated. The results showed that SOF maturation media containing histidine at 0.5 mg/mL could significantly (P ≤ 0.01) improve oocyte IVM when compared to control and other concentrations. The addition of histidine to FertiCult media at 0.5, 1, and 3 mg/mL did not improve the IVM, IVF, CR, or IVC percentages. However, the embryos in the control group were unable to grow into a morula or blastocyst in the SOF or Ferticult, whereas adding L-tyrosine to the SOF or Ferticult at various concentrations improved IVC (morula and blastocyst rates). There was a significant (P ≤ 0.01) increase in IVM when hisitidine was added to SOF medium at a concentration of 0.5 mg/ml compared with L-tyrosine. Also, there were significant (P ≤ 0.01) increases in IVC when L-tyrosine was added to SOF medium at concentrations of 1 and 10 mg/ml compared with histidine. In conclusion, the supplementation of the SOF and FertiCult with the amino acids histidine and lysine could improve the maturation rate of oocytes and development of in vitro-produced buffalo embryos; however, further research is needed to examine their effects on the fertilization rates of oocytes and embryonic growth at different age categories and seasonal localities for future perspectives.