Efeito dietético da relação proteína: lipídeo no desempenho zootécnico e atividade de enzimas digestivas do hepatopâncreas de pós-larvas do camarão-pitu Macrobrachium carcinus (LINNAEUS,1758)

Abstract

This study aimed to determine the dietary effect of protein/lipid ratio in the zootechnical performance, and activity of digestive enzymes in post-larval (PLs) painted river prawn. The work of zootechnical performance was conducted at the Center Integrate Fisheries Resources and Aquaculture, belong to the 4ª Regional Superintendency of Sergipe of Company for the Development of San Francisco and Parnaiba rivers valleys. Were evaluated six experimental diets with three levels of crude protein (220, 300 and 350 g kg⁻¹) and two levels lipids (80 and 100 g kg⁻¹) offered to (PLs) with middle weight (1.86mg ± 0.65) in a factorial arrangement (3x2) with eight replicas, distributed in six different relations dietary protein/energy (P/E):11, 12, 16, 17, 19 and 20 mg CP KJ⁻¹ GE g⁻¹ shared in 48 experimental units. The zootechnical variables of biomass gain, hepatosomatic index and survival were evaluated. The activity of digestive enzymes was determined through the use of hepatopancreatic tissues to identify total alkaline proteases, chymotrypsin, trypsin, leucine-aminopeptidase, and lipase read in spectrophotometer. All data were analyzed by means of ANOVA one way and two way through software R®. The zootechnical performance was affected by the combination employees, and great diet (350 g CP kg⁻¹ 80 g L kg⁻¹), expressed through the dietary ratio P/E 19. No difference was found for the survival (p=0.5055). The digestive enzymes presented activity changed positively by the experimental diets tested in PLs, except the activity of leucino-aminopeptidase, which not expressed difference (p=0,4936). The ratio P/E of 11 showed a higher value for hepatosomatic index (%) between the treatments. The proteases exhibited higher concentration according to the increase of proteins, as well as the lipase, who expressed greater activity regardless of the amount of protein. These results indicate that best P/E for PLs, is with 19 mg CP KJ⁻¹ GE g⁻¹ through diet (350 g PC kg⁻¹ 80 g L kg⁻¹) that presented synergy and better adjusted to the food needs.