Effect of method and media type for in vitro fertilization on equine (Equus ferus caballus) embryo development

Abstract

Demonstrating the role of in vitro fertilization in the equine family, the current study aimed to monitor the rates of equine in vitro-fertilized and cleaved oocytes based on microdroplet and intracytoplasmic sperm injection (ICSI) methods. The fertilization process was carried out in four main media consisting of Tyrod?s albumin lactate pyruvate and TCM-199 (1:1): F (TCM-199); assigned for the ICSI method, FI (contained 0.01 mg/ml heparin + 0.01 ng/ml hypotaurine), FII (contained 0.3 mg/ml calcium chloride + 0.1 mg/ml magnesium chloride) and FIII (contained 0.05 mg/ml hypotaurine-epinephrine). The results indicated an increase in the fertilization rate by the ICSI method (65.71%) compared to the microdroplet method (39.25%) (p 0.04). The rates of unfertilized and degenerated oocytes in the ICSI method decreased, compared to the microdroplet method, to 8.57% and 25.72%, respectively; p< 0.001. The rate of fertilized oocytes in the FI medium increased to 47.61% (p< 0.05) compared to oocytes of FII and FIII treatments (37.64% and 30.00%, respectively). On in vitro culture, the rate of cleavage increased to 74.62% in the CI medium (SOF) compared to those in the CII medium (DMEM-F12) (61.29%); p <0.001. Zygotes cultured in the CII medium achieved a higher rate of blastocyst formation (30%) compared to those in the CI medium (26.31%); p< 0.001. Applying the ICSI method and SOF culture media led to high yields of equine embryos.