Effect of repeated Superovulation on superovulatory response and embryo recovery in Sahiwal cows

Abstract

Twelve elite Sahiwal donor cows were repeatedly superovulated four to five times with an interval of 75 to 100 daysbetweentwosuperovulations to . determine the effect of 
respeated gonadotrophicsuperstimulation of 
ovaries on superovulatory response and embryo recovery during a period of one year. The mean 
numbers of corpus luteum / ovulations observed 
were 10.16±0.62, 9.75±0.64,7.75±0.56, 
5.91±0.37 and 4.66±0.87 in five attempts respectively. The mean number of embryo recovery was 6.83±0.70, 4.83±0.52, 
3.41±0.35, 3.08±0.39 and 2.33±0.87. The mean number of transferable embryo was 5. 16±0.65, 3.5±0.37, 2.5±0.31, 2.0±0.27 and 2.0±0.57. Repeated superstimulation of ovaries by exogenous gonadotropin treatments had a tendency towards decreasing number of ovulations,. embryo recovery and transferable 
embryos per cow during a period of one year. It is also observed that in one year fiverepeatedsuperovulations and flushing were possible only 
in 25% Sahiwal donors whereas in 75% cows only four repeated superovulation and embryo 
recovery were done successfully.