Investigation of the effect of progesterone applications on pregnancy rate in different periods of cows

In this study the effects of the intravaginal devices on the pregnancy rate which were used in different durations to increase the fertility were investigated. In the study 100 Holstein kind of cows which got 1-3 lactation were investigated. Cows were divided into two groups, 50 for CL and 50 for non CL. Progesterone included silicone was applied for 7 days in group I and it was applied for 12 days in group II. PGF2a was injected in both groups after silicones were removed. 60 hours later from the application of PGF2a to the cows, fix time artificial impregnation was done and during impregnation, GnRH injection was applied. After 30th day of the impregnation, pregnancy examination was practiced via USG and pregnancy rates were stated in order of %56 (28/50) and %44 (22/50). In addition, it was seen that the difference between the rates was not significant statistically. As a result, it was found that progesterone included intravaginal devices might be an alternative for the short-term application instead of long-term application.