Influência da adição de diferentes óleos na dieta sobre as expressões dos genes miostatina e de sinalizadores de adipocitocinas no músculo longissimus dorsi de ovinos.

Abstract

The production of sheep in Brazil has undergone significant changes in recent years due to the increase in the demand of the consumer market for quality products, which leads to the need to obtain younger finished animals associated with the use of adequate production systems. Obtaining quality meat is dependent on several factors such as genetics, age, sex, handling, nutrition and environment. Therefore, the aim of this thesis is to analyze the effects of the addition of different oils in the diets on the gene expressions: Myostatin and adipocytokine signaling genes in the Longissimus dorsi muscle of sheep. Forty animals were selected and distributed in four blocks and four treatments, being a control group. All treatments were composed of voluminous elephant grass cv. Purple and concentrated based on ground corn, soybean meal, mineral salt and calcitic limestone. The determination of each treatment was the addition of 4% of oils, being the treatment 1 with soybean oil, treatment 2 with addition of 4% of frying soybean oil and treatment 3 was added 4% of palm oil. The animals were slaughtered after 90 days of confinement and a 5 g sample of the Longissimus dorsi muscle from each animal was collected and stored in liquid nitrogen. Gene expression analyzes were performed from RNA extraction, followed by real-time PCR containing Sybr green fluorochrome for the Myostatin, FASN, ACLY, ALDOC, ENPP1 and DUSP10 genes plus the GAPDH gene as internal control. All relative gene expressions were submitted to ANOVA and the means were compared by the Dunnett test at 0.05. The expression of Myostatin gene was significantly lower with the addition of soybean oil compared to the control treatment. For the adipocytokine signaling genes, there was no significant difference between treatments for the ACLY gene, but for the ALDOC gene all treatments with oil additions regulated the expression for less than the control group. The DUSP10 gene showed the highest level of expression among the genes, but only the treatment with soybean oil addition was significantly low in relation to the control. For the ENPP1 gene, the additions of the palm oil and fry soybean regulated the expression significantly up and the FASN gene was significantly down-regulated only with the soybean oil-containing treatment relative to the control group. It is concluded that the additions of the different oils in the sheep diet regulated the expressions of most genes for more or less, which may influence the muscle development and the metabolic pathways responsible for the fatty acid biosynthesis in the Longissimus dorsi muscle of sheep.