Morphological and hormonal changes after superovulation in cows treated with Neutra-PMSG

Morphological changes in ovaries and hormonal changes as well as changes in Na, K, Ca, Mg, and P blood plasma levels were observed after superovulation induced by the administration of PMSG and the neutralization of this hormone with monoclonal antibodies Neutra-PMSG administered either 72 or 108 h later. The introduction of Neutra-PMSG 108 h after PMSG injection clearly decreases the number of surviving non-ovulated follicles with a diameter > 10 mm (1.7 +/- 0.8 vesicle in an individual cow on the average) in comparison to the group without Neutra-PMSG (19.4 +/- 9.5). The efficiency of ovulation in the group treated with Neutra-PMSG in the 108th h of the experiment (8.2 +/- 4.6 corpora lutea per cow on the average), did not differ statistically from the group treated with PMSG only (12.4 +/- 10.6). Early administration of Neutra-PMSG (72h), totally inhibits superovulation. Observations showed, that injection of Neutra-PMSG in the 108th h, caused a considerable decrease in the estradiol level, beginning with the 120th h of the experiment. Determination of the progesterone blood plasma level reflects the number of corpora lutea and can be helpful in evaluating the effects of superovulation. Superovulation did not effect the level of Na, K, Ca, Mg, and P in the blood plasma.