Age at puberty and mammary gland development in lambs under low and high rates of growth

Abstract

To become a good milk producer it is necessary that the ewe has its mammary tissue developed in a structural way since that milk production is directly proportional to the number and activity of the secretory skin cells. The food plan can influence the growth, reproduction, mammary development, and future milk yield of ewes. Thus, the aim of this study is to evaluate the effect of two levels of nutrition in the development of the mammary gland of weaned Bergamasca lambs at 30 days of age. The project will run in the Research Unit and Sheep Milk Production, Faculty of Veterinary Medicine, UNESP, Botucatu campus, SP, with 20 lambs Bergamasca confined throughout the experimental period and distributed in two treatments: A ) The lambs are fed on a diet with 15% CP and 72% TDN, designed to obtain average daily weight gain of 300 grams and B) the lambs receive diet with 10% CP and 65% TDN, formulated to obtain the gain daily weight of 180 grams. The diets are balanced on the scale of nutritional requirements for replacement ewe lambs (NRC, 1985). Will be assessed the following variables: the dynamics of body weight, growth, and development of the mammary gland, and the development of the reproductive and behavioral aspects related to puberty.(AU)