Cattle embryos development through in vitro techniques using thyroxine hormone as a culture media supplement

Abstract

The aim of the present study was to produce cattle embryos through in vitro by supplementing culture media with thyroxine hormone. Fresh cattle ovaries and oviducts were collected from a local abattoir in 0.9% saline solution (30-35 °C) supplemented with antibiotics (200 IU/ml penicillin and 50 g/ml streptomycin) and transported to the laboratory within 2-3 h following slaughter. Total 707 cumulus oocyte complexes (COCs) were collected from visible surface follicles (3-8 mm) by aspiration method with 19 gauge hypodermic needle. The COCs were washed 5-6 times and matured for 24 h in maturation media supplemented with thyroxine hormone (T4) with different concentrations (viz.20, 50 and 100 ng/ml) at 38.5 ºC in CO2 incubator. After 24 h oocytes were co-incubated with in vitro capacitated sperms in Fert-BO media for 15-18 h. After removing cumulus cells oocytes were then washed 1-2 times with RVCL media and cultured in 100 μl RVCL medium supplemented with T4 and cultured for cleavage. The mean percentage of cleavage rate was 23.80 ± 2.04 in control group. The highest mean percentage of cleavage rate was 52.59 ± 5.93 in 100 ng/ml treatment group. From the present study it could be concluded that thyroxinehormone exhibited significant increase in the cleavage rateand early embryo development.