Aditivos naturais promotores de crescimento em dietas para tilápia do Nilo

Abstract

The research was developed in Laboratory of Ponderal Evaluation in aquatic Animals (LaAqua), located in the Department of Fisheries and Aquaculture of the UFRPE, with the aim to study the effect of the natural promoter growth additive in feed for Nile tilapia, through the evaluation of the digestibility of the dry matter, crude protein and crude energy of the rations, the performance and the morfometry of the mucosa gut of Nile tilapia. The used natural additives had been the alcoholic extract of propolis and garlic powder in the levels of 0.0, 0.5, 1.0 and 1.5 % and 0.0, 1.0, 2.0 and 3.0% of inclusion in the ration, respectively, arranged in a design randomized with four treatments and six repetitions. In the performance, that was carried through in aquariums of 70L, in a system of closed water circulation with the use of biofilter, the profit of weight, apparent alimentary conversion, consumption of apparent ration, hepatossomatic index, protein efficiency tax, viscerosomatic fat index, digestives somatic index and the morfometry of the mucosa gut had been evaluated, on the basis of the intestinal villus height. In the digestibility experiment had been used 320 juveniles of Nile tilapia with initial average weight of 20,00 ±5,0g The rations hadbeen supplied “ad libitum” (of 45 in 45 minutes) in small portions, in the period of the 8:00 to 17:00 h. The excrements had been collected in the deep one of the aquariums, daily, to each six hours. In the condition where the experiment was carried through, the use of the alcoholic extract of propolis that as additive promoter of growth for Nile tilapia, did not imply in improvement in the performance, however it provided one better energy exploitation of the ration. The garlic powder as additive in rations for youthful the Nile tilapia, did not provide positive effect as promotional of growth, in the studied levels.