Effect of energy on milk production of anglo-nubian does

Abstract

A research was carried out, during 22 weeks at the Brazilian National Research Center on Goats (Centro Nacional de Pesquisa de Caprinos - CNPC), Sobral, CE, Brazil, to determine the effect of energetic supplementation on quantity and quality of the milk produced by Anglo-nubian does. Twenty-eight adult does were alocated, according to type of parturition and milk production to four levels of energy. All animals were allowed to graze on native thinned caatinga pasture and, in addiction, they received 243, 465, 690 and 927 g of dry matter (DM) per day, in the form of concentrate supplementation. The simple correlation between milk production and fat percentage was -0.75. The levels of energy x week interaction influenced (P < 0.05) the milk production. That condiction indicated that the energetic supplementation had effect in one lactation stage only (last six weeks, during the dry season). The linear regression model presented a good fit of the with a coefficient of determination of 62%. The economic analysis of the data showed that the energy level one was the most economic.