Comparison of Efficiency of PMSG and FSH Treatment for Superovulation in the Same Holstein Cows

Abstract

The 23 donor cows were administered with 3000 IU of PMSG and a total of 2440 AU FSH followed by PGF2αanalog at about 80 days intervals by turns. Thereafter, the efficacy of the 2 treatments were compared using the same cows on the number of corpora lutea, embryos recovered and returned estrus. The cows treated with PMSG resulted in more corpora lutea than with FSH (11.3 vs 7.5; P<0.05). However, there were no differences between 22 PMSG-treated cows and 17 FSH-treated cows with more than 2 corpora lutea, on the average number of corpora lutea (11.8 vs 10.1), recovered eggs (6.7 vs 6.8), fertilized eggs (5.9 vs 5.4) and normal embryos (4.9 vs 4.6), respectively. Through the experiment, two out of 23 cows showed a poor response (with less than 5 corpora lutea) while 12 cows showed a good response (with more than 6 corpora lutea) in either treatment. On the other hand, the remainders had an opposite response in each treatment. There was no difference between 2 treatments on the days from superovulation to estrus. Consequently, it seems that the efficacy of the next treatment can be predicted from the results of the first treatment.