Digestibilidade aparente e verdadeira de proteína e aminoácidos em alimentos para tilápia do Nilo / Apparent and true digestibility of protein and amino acids in foods for Nile tilapia

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The objective of this work was evaluate the apparent and true digestibility of the protein and of the amino acids of some foods by the techniques the decantation and dissection for Nile tilapia (Oreochromis niloticus) of the thailand line, in growth phase. Two trials were carried out, being the first led among the months of October to December of 2007 and the second, led among the months of September to November of 2008, at the fish nutrition laboratory of the Animal Science Department of the Federal University of Viçosa. For the two experiments, the treatments had consisted of six diets, each one with a single source protein different (corn, wheat bran, soybean meal, corn gluten meal, fish meal). An additional group was fed with free diet of protein for quantification of the endogenous fraction and determination of the coefficients of true digestibility. The diets were formulated to contain 32% of crude protein for evaluation of the protein foods (soybean meal, corn gluten meal, fish meal) and 6.5% of rude protein for evaluation of the energy foods (corn, wheat bran). In the first experiment, two hundred and fifty two tilápia with weight 3109.68g, were allotted among the experimental randomized blocks design, with five treatments, six replicates by treatment and seven fishes for experimental unit. Three made aquariums of fiberglass were used, of conical format and with useful volume of 250 liters, endowed with individual systems of aeration, provisioning and drainage of water, with minimum renewal of water of 25% a day. After the last feeding of the day, all of the aquariums were clean and 50% of the renewed water, making possible like this the removal of any diet residue that could contaminate the feces of the fish. For the decantation technique, the values of the coefficients of apparent digestibility for the protein and the average of the amino acids are: corn 83.57 and 82.45%, wheat bran 82.87 and 81.47%, soybean meal 91.12 and 89.41%, corn gluten meal 90.07 and 87.78%, fish meal 83.53 and 81.65%, respectively. The values of the coefficients of true digestibility for the protein and the average of the amino acids are: corn 90.02 and 89.60%, wheat bran 89.62 and 89.14%, soybean meal 93.58 and 91.88%, corn gluten meal 92.50 and 90.34%, fish meal 86.01 and 84.27%, respectively. In the second experiment, nine hundred tilapia with weight 3158.45g, were allotted among the experimental randomized blocks design, with five treatments, six replicates by treatment and twenty-five fishes for experimental unit. The fish were maintained in six aquariums of polyethylene, with useful volume of 300 liters, endowed with individual systems of aeration, water supply and bottom drainage disposed in recirculation system and minimum renewal of water of 25% a day. The fish were fed with the experimental diets for five days. For the dissection technique, the values of the coefficients of apparent digestibility for the protein and the average of the amino acids are: corn 74.69 and 73.62%, wheat bran 73.74 and 72.81%, soybean meal 86.01 and 84.66%, corn gluten meal 85.19 and 84.29%, fish meal 76.74 and 75.56%, respectively. The values of the coefficients of true digestibility for the protein and the average of the amino acids are: corn 85.21 and 83.97%, wheat bran 84.41 and 83.74%, soybean meal 87.22 and 87.51%, corn gluten meal 87.97 and 87.34%, fish meal 79.58 and 78.44%, respectively.

ASSUNTO(S)

true digestibility oreochromis niloticus avaliacao de alimentos para animais oreochromis niloticus digestibility techniques técnicas de digestibilidade digestibilidade verdadeira

ACESSO AO ARTIGO

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