Morfometria dos tecidos hepático e intestinal e crescimento de juvenis de tilápia-do-Nilo provenientes de reprodutores e matrizes alimentados com nucleotídeos

Abstract

The objective of this study is to evaluate the morphometry of the intestinal and hepatic tissues and the growth of juveniles of Nile tilapia, originated from broodstock fed with purified nucleotides. During 30 days, 2.000 larvae (0,013±0,00g) were housed in 70L tank, distributed in a completely randomized structure composed by five treatments and four replicates. The broodstock were fed with diets containing 28% of digestible protein, 2.800kcal of digestible energy and supplemented with 0,00; 0,25; 0,50; 0,75 and 1,00% of nucleotides. The larvae originated from these animals were fed with commercial feed containing 50% crude protein and 60mg of 17α-methyltestosterone/kg. At the end of the experimental period, from each experimental unit the juveniles were anesthetized, weighed and measured to evaluate the zootechnical parameters. Still, from each experimental unit, two juveniles were euthanized, dissected and livers and intestines were fixed for later histological processing. The juveniles originated from broodstock fed with 0,75% of nucleotides diets presented higher total length (p=0,07; 3,35±0,09cm). Other growth parameters were not altered by the feeding. The feed supplementation with nucleotides also promoted an increase in the enterocytes (p=0,00), and feed containing 1,00% reduced (p=0,04). The height of the villousness, the height of the microvillousness and the morphometry of the hepatocytes were not influenced by the feed. It was concluded that dietary supplementation with purified nucleotides for Nile tilapia broodstock interferes in the growth and morphometry of the offspring intestinal tissue.