[Uterus development in swine from birth to 8 months of age]

Macroscopic examination was applied to the ovaries and histological tests to the uterus of 108 pigs aged between one and 240 days. The results have shown that the growth of the uterus in swine had not taken place with continuity. Extraordinarily strong thickness growth of the endometrium and myometrium was observed over the first three months of age. Thickness growth of both layers then continued at reduced rate. The uterine glands began to develop from superficial epithelium in the second week of age and reached the basal part of the endometrium in the fourth week. Both the number of uteroglandular sections per visual field and the glandular surface over the whole area of the endometrium, as recorded from cross-section specimens, increased strongly over the first three months of age, followed by less marked change. Continued development and maturation of the elements involved took place between the twelfth and 24th weeks of age, with the uterine glands acquiring capacity of secretion. Stagnation is uterus development and growth was observed at the age of over 180 days. The most favourable date for zootechnical stimulation of puberty was considered to lie in the period between 170 and 200 days of age, whereas biotechnical induction of puberty might give best results when applied at an age between 180 and 200 days.