Features of the growth and formation of the physique of nenets reindeer from birth to puberty

Abstract

In the Yamalo-Nenets Autonomous District were studied 169 heads of Nenets deer from birth to 18 months of age The maximum rate of weight gain of live weight of calves is observed in the first 6 months of postnatal development and has sexual differentiation: in males it was 52.5, in females – 46.5 kg. From 6 to 12 months of age, which falls during the wintering period, in the studied groups of deer there was a drop in absolute indicators of live weight gain to minus values: males -5.3 kg, females -1.7 kg. In the period from 12 to 18 months of age, the absolute growth rates of males and females turned out to be equal. The rate of linear growth and the formation of the physique of young deer in the period from birth to 6 months of age, no significant difference between males and females was found either visually or instrumentally.. During the first wintering period, an increase in absolute value was observed by measurements associated with the growth of the skeleton: height at the withers, height at the elbow, head length, chest depth, oblique length of the butt. The age period from 12 to 18 months is characterized by a significant increase in linear body sizes in the studied deer, but the difference in almost all measurements did not exceed 4%. A comparison of 10 indices of physique in animals showed that at 6 and 18 months of age, the main proportions of the physique are close, which indicates a high rate of formation of the physique in young domestic reindeer. A comparison of the physique indices revealed no signs of sexual dimorphism for any of them, except for the pelvic index, which was higher in females at all age periods and the broadbodied index at 18 months of age.