Use of radioimmunoassay technique for the determination of post-partum ovaric activity in high and low milk production in dairy cows

The principal objective of this study was to determinate the post-partum ovarian activity in milking cows of high and low production in one farm of ecuadorian highland. For this experiment was necessary to use 48 animals between second and sith calving, the milk samples were collected according one pre-stablished protocol and the same was: one sample 5th or 6th days, twice a week until the cows were pregnacy and 180 days after parturitium if the cow is open. Additional data were compiled in each farm and both the results of the progesterone by RIA were used to determinate the diferents reproductive parameters in the post-partum of the cows. The most of reproductives parameters in the post-partum of the cows in the both group didn't have significance but the conception rate, services per conception, number of pregnacy cows and percentaje of non visibles heats had one high significance between the treatments