| Popis: |
To study of the effect of the gonadotropic preparation on the hormonal status of the infer-tile cows, 47 red-and-white cows belonging to the breeding farm (Voronezh Region, Russian Federation), having an ovarian hypofunction, at the age from 3 to 8 years old and with the live weight of 480-600 kg, were included in the experiment. The animals in the experimental group (n=27) received a single dose of placental gonadotropin, i.e. Follimag at the 1000 I.U. dose. The animals not injected with the preparation (n=20) formed the negative control group. Cows’ blood samples were taken before injection, 4, 8 and 14 days after it. The hormone concentration (progesterone, es-tradiol-17β) was determined in blood serum by the immunoenzymometric analysis. Introducing the preparation led to the increase of the progesterone level in the blood of the experimental group cows on average of 2.85 times and estradiol-17β increased by 23.2% as compared with the background, progesterone increased 1.95 times and estradiol-17β by 9.0 % compared with the control on the 14th day of the experiment. It was established that the degree of the ovarian hormonepoietic reaction manifestation and its direction in prescribing the exogenous gonadotropins depends on the time of the preparation injection relative to natural waves of the follicles growth. Using the gonadotropic preparation provided a 21.6-time increase in the blood content of progesterone on the 14th day of the experiment and that of estradiol-17β of 1.29 times, when injected at the beginning of the follicles growth wave. When administered at the follicular atresia stage, it led to an increase in the progesterone level of 2.1 times and that of estradiol-17β of 1.29 times. |
