TDK conference 2017

Despite the multitude of synchronization protocols with TAI, little is known about LH wave properties. The aim of our work was to determine the LH wave' characteristics and the consequent ovulation of cows involved in three investigated protocols with TAI. Archived data from the survey of 60 cows of the Holstein-Friesian breed were used. The cows were divided into three equal groups. Group A was subjected to the modified Double Ovsynch, group B modified Presynch, while group C was subjected to the Ovsynch protocol. The blood samples were taken for the analyses of LH and progesterone concentrations, and the cows selected for LH analysis were examined ultrasonically to determine ovulation. The results show that all protocols induced ovulation in dairy cows. Groups A and B showed the advantage of using the presynchronization protocols because the LH wave was induced at the desired time, while in group C, it was of spontaneous nature. In all three groups there was a development of dominant follicle whose diameter in groups B and C exceeded the desired size. At the time of insemination, groups A and B had the required low levels of progesterone while in group C it was slightly higher. The percentage of pregnant animals was lowest in group C, due to too early onset of LH surge. Given the results achieved, it would be good to repeat research on a larger number of cows.