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 mamary tissuedeveloped in a structural way, since that the milk production is directly proportional to thenumber 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 studyis to evaluate the effect of two levels of nutrition in the development of the mammary gland ofweaned Bergamasca lambs with 30 days of age. The project will run in the Research Unit andSheep Milk Production, Faculty of Veterinary Medicine, UNESP, Botucatu campus, SP, with 20lambs Bergamasca confined throughout the experimental period and distributed in twotreatments: A ) The lambs are fed on diet with 15% CP and 72% TDN, designed to obtainaverage daily weight gain of 300 grams and B) the lambs receive diet with 10% CP and 65%TDN, formulated to obtain gain daily weight of 180 grams. The diets are balanced on the scaleof nutritional requirements for replacement ewe lambs (NRC, 1985). Will be assessed thefollowing variables: the dynamics of body weight, growth and development of the mammarygland, the development of the reproductive and behavioral aspects related to puberty. (AU)