Net requirement of protein and energy of Santa Inês ewe in lactation

Abstract

This study aimed to obtain the protein and liquid energy requirements from lactating ewes under two nutritional managements during pregnancy and under two types of pregnancy. Experimental tests were conducted at the Animal Metabolism and Calorimetry Laboratory on Department of Animal Science from Veterinary School of UFMG. For the experimental testing, were used 28 Santa Ines sheeps in a completely randomized design under 2 x 2 factorial arrangement, considering two pregnancy types (single and double) and two nutritional managements (with and without restriction). Sheeps were placed on the platform and contained for milking. To analyse data regarding milking weeks it was used the model of repeated measures in time. The experimental groups were evaluated using the SNK test at 5% significance level. (1) Diets were compound of corn meal (Zea mays), soybean meal (Glycine max), chopped Tifton grass hay (Cynodon spp.) and limestone. Sheep’s specific mineralsupplement was offered ad libitum to the animals Milk production was not affected by nutritional management, as the amount of fat, protein and, energy from milk. The same results were observed to energy and protein requirements. This fact shows that the nutritional management, per se, was not able to change the variables studied. The double pregnancy produced more milk, fat and protein in milk increasing its energy value. Energy and protein requirements were higher in ewes with double pregnancy. Milk production, energy and protein requirements were higher until the tenth week of lactation. Energy and protein nutritional requirement followed the milk production curve.