Parâmetros metabólicos e reprodutivos de fêmeas suínas pré-púberes após suplementação da dieta com ácidos graxos poli-insaturados

Abstract

The use of omega-3 polyunsaturated fatty acids (PUFA) in the diet of animals has shown benefits, but there are few studies in sows demonstrating the potential effects of adding this supplement to the diet. The objective of this study was to evaluate the effects of supplementing with omega-3 source of docosahexaenoic acid (DHA) to female swine after weaning. Sixteen females were alocated to two groups: control, which received only the diet recommended for their age; and the omega-3 group, which received 3.5 g DHA per animal per day, mixed to the diet. The supplementation lasted 52 days. After that period, females were slaughtered and their ovaries were collected, to be evaluated through RNA expression and immunohistochemistry. Three blood samples per female were collected, before and during supplementation, to evaluate the following metabolic indicators: triglycerides, total cholesterol, low (LDL-cholesterol) and high density lipoproteins (HDL-cholesterol), aspartate aminotransferase (AST), gamma glutamyl transpeptidase (GGT) and estradiol. The females were weighed weekly and their daily feed intake was recorded during 17 days, while they were housed in individual cages, to calculate feed conversion. Females in the omega-3 group presented lower daily feed intake and better feed conversion compared to control females (P < 0.05), although weight gain did not differ between groups (P > 0.05). Total cholesterol plasma levels were lower in females receiving DHA (P < 0.05), while animals in both the groups presented reduced HDL-cholesterol levels at the last collection, corresponding at D52 (P < 0.05). Supplemented females presented lower immunolabeling for leptin and its receptor (ObRb) in the cytoplasm of oocytes included in primary follicles (P < 0.05), and lower gene expression for the enzymes desmolase, aromatase and luteinizing hormone receptor (P < 0.05) obtained from follicular cells. The inclusion of omega-3 as a source of DHA in the diet of prepubertal sows resulted in better the zootechnical performance of the animals, however there was a reduction of some reproductive parameters evaluated.