Dynamics of urea content in blood of sows depending on peculiarities of nervous system activity

The article presents the results of studies on the dynamics of urea content in blood serum of sows depending on the type of higher nervous activity and the initial tone of the autonomic nervous system under exposure to technological stimulus. Dry sows of large white breed were used for experiments. Types of higher nervous activity in pigs were determined using the method of conditioned food reflexes. According to the studying of conditioned reflex activity 4 experimental groups were formed, 5 animals in each. The 1-st group consisted of sows with strong balanced mobile, the 2-nd – strong balanced inert, the 3-rd – strong unbalanced, and the 4-th – weak types of higher nervous activity. Then in experimental animals we studied the tone of the autonomic nervous system using trygeminovagal test, by the results of which we formed 3 experimental groups (normotonics, sympathicotonics, vagotonics), 5 animals in each. Before exposure to technological stimulus and in 1, 3, 7, 14 and 28 days after its impact, blood samples were taken for biochemical studies in all experimental animals. Regrouping and moving of pigs into another building were used as a technological stimulus. In the conditions of relative rest in sows, depending on the type of autonomous regulation of the cardiovascular system, the significant differences of urea content in blood serum were not detected. Instead, in the conditions of relative rest in the representatives with weak type of higher nervous activity, lower urea content in blood serum was established than in the representatives of strong types. Due to the exposure to technological stimulus in animals of all groups, an increase in urea level in blood serum was detected. However, the degree of changes manifestation in urea content in blood serum differed in sows, depending on the type of higher nervous activity and the initial tone of autonomic nervous activity. Despite that found differences were statistically significant, they were within the normal range. Thus, the urea content in blood serum of sows is somewhat limited by the typological features of the nervous system.