Influence of different mineral nutrition level on the functional morphology of thyroid gland of heifers

The studying of functional morphology of the thyroid gland associated with age and the level of mineral food, which is carried out by means of a morphometric method of research demonstrates existence of the expressed age dynamics of a morphofunctional condition of a thyroid parenchyma. At animals with an optimum level of mineral food in diets in 12, 15 and 18-month age concentration of a thyroxine and triiodothyronine is lower that testify to increase of concentration of endogenous hormones. Positive correlation between the mass of a thyroid gland and body weight of animals is established. Weighing of a thyroid gland of girls of various age testifies that there is a reliable growth of mass of body to 9 and 12 monthly age. With age at animals the relative volume of a colloid of a thyroid gland fluctuates. At development of full-fledged sexual cycles this indicator decreases that testifies to increase of endocrine function of gland. And more authentically it happens at girls to an optimum level of mineral food. Opposite regularity it is noted concerning an epithelium of a thyroid gland. The relative volume of a stroma of body remains quite stable and changes slightly.