[Regulation of the reproductive functions of cows by hormonal preparations]

Studied was the effect of some hormonal preparations--progesteron, GnRH, and HCG with progesteron--injected immediately prior to artificial insemination on the reproductional functions of cows raised under industrial conditions. It was found that the conception rate of cows at first insemination was highest upon treatment with GnRH--67.86 percent, i.e., by 14.29 percent higher than that of the control group. The same trend remained with the total conception rate. Lowest was the use of pellets per cow--1.33--with animals treated with GnRH prior to insemination. The application of GnRH (Berlin Chemie, GDR) was sufficiently effective at single i/m injection before artificial insemination. It could be employed to raise conception rate as well as to lower the use of pellets for impregnation of cows.