Influence of the sperm fertilization doses on chromosomal abnormality rates of 4-day-old bovine embryos

SEBASTIÁN DEMYDA PEYRÁS; MANUEL HIDALGO; JESUS DORADO; MIGUEL MORENO MILLÁN

Antalya

Conferencia; The 15th Annual Conference of the European Society for Domestic Animal Reproduction (ESDAR); 2011

ESDAR ( European Society for Domestic Animal Reproduction)

This cytogenetic study was undertaken to quantify, by chromosomal analysis, the incidence and type of chromosomal abnormalities on in vitro-produced (IVP) bovine embryos. Four groups of 150 matured oocytes were in vitro fertilized for 18 h with a final sperm concentration of 1 · 104, 1 · 105,1 · 106 and 1 · 107 cells/ml. Presumptive zygotes were cultured for 96 h, collected and fixed individually for chromosomal analysis. A total of 225 embryos were suitable for chromosomal analysis following a standard method. Rates ofhaploidy, diploidy, aneuploidy and polyploidy were determined individually. There were no differences (p > 0.05) in chromosomal alteration rates at concentrations of 1 · 104, 1 · 105 and 1 · 106 cells/ml. The incidence of polyploidy strongly increased (p < 0.01) at concentration of 1 · 107 cells/ ml. The fertilization rate obtained with the lowest concentration (1 · 104 cells/ml) was significantly lower (p < 0.05) than those obtained with the other concentrations. Acceptable fertilization rates with low chromosomal abnormalities can be achieved with a final concentration of 1 · 105 or higher. In conclusion, the use of low sperm concentration doses in the IVF process in cattle drastically reduces the number of chromosomal abnormalities, without affecting the embryo yielding.