Diferentes níveis de gordura rica em DHA (ALL-G Rich) na nutrição de ovinos

Abstract

Fat sources are essential components in ruminant feeding since it provides 2.25 times more energy than carbohydrates. New feedstuff sources such as algae fat are an interesting option due to their different type of fatty acids, including the docosahexaenoic acid (DHA, omega 3). However, caution should be taken when including fat in diets since polyunsaturated lipids may have deleterious effects on rumen environment. This study aimed to evaluate the effects of increasing dietary levels of ALL-G Rich®, a commercial product containing DHA, on the intake and nutrient digestibility in sheep, as well as its effect on serum concentrations of metabolites. The experiment was conducted at the Goat and Sheep Research Unit - Capim Branco Experimental Farm from the Federal University of Uberlandia. Five crossbred ewes (Dorper x Santa Ines) with an average age of six months and 30 kg of body weight were used. Sheep were allocated in metabolic cages and distributed in a 5x5 Latin square. The metabolic cages were equipped with a feed, water and salt troughs, and wooden slatted floor. The animals were divided into 5 treatments: 0, 1.5, 3, 4.5 and 6% inclusion of ALL-G Rich® on a dry basis of the concentrates. The corn silage was used as roughage source and the roughage:concentrate ratio during the whole experiment was 30%:70%. An apparent digestibility assay was carried out to evaluate the intake of dry matter and nutrients, as well as their respective digestibilities. In addition, the feeding behavior of the animals and the protein metabolites, energy and liver enzymes were evaluated. There was no effect on the intake and digestibility of dry matter and nutrients, feeding behavior and protein metabolites with the increasing inclusion of ALL-G Rich®. Serum cholesterol, alkaline phosphatase, and gamma-glutamyltransferase concentrations increased in response to higher inclusion levels, whereas LDL levels reduced. Thus, the inclusion of up to 6.00% ALL-G Rich® on a dry basis of the concentrate increased the energetic and hepatic metabolism without damaging animal health. On the other hand, the reduction of LDL indicates a benefit on sheep health.