System production x nutritional requirements: beef female and calves from birth to weaning

Abstract

Objective was to evaluate the studies on the nutritional requirements of cows and calves Nellore, seeking data requirements of energy and protein fractions for these animals from birth to weaning. There are few publications that seek nutritional requirements of cows and beef calves raised in tropical conditions. There is variation between the reported requirement for energy and protein for animals of European origin and zebu. We used the equations obtained by studies conducted in Brazil to produce tables with the net energy requirements, energy intake, total digestible nutrients for maintenance and gain weight, based on cows in different stages of lactation and body size. For lactating calves different rates of gain and body weights.As for the protein fractions. Based on the data obtained it is concluded that cows with CMS approximately 2% of body weight can not gain 1 kg / day weight, since the demand for nutrients exceeds the ingestive capacity. Calves are weaned at about 7 months and weight around 200 kg should receive supplementation from the 2nd month of life.