Intestinal Histomorphometry and Biometric Indexes of Tambaqui (Colossoma Macropomum) Grown Under Different Feeding Rates / Histomorfometria Intestinal E Índices Biométricos De Tambaqui (Colossoma Macropomum) Cultivado Sob Diferentes Taxas De Alimentação

Abstract

Optimizing the production system of tropical species in tanks requires scientific studies on proper food management, with the determination of the ideal feed rate, aiming at the best rates of zootechnical performance and carcass yield associated with the lowest production cost for the producer. The aim of this study was to evaluate the histomorphometry of the intestine and the biometric indices of tambaqui (Colossoma macropomum) grown under different feeding rates. The study was conducted at the Fish Culture Research Center of the Universidade Federal de Rondônia, located in the city of Presidente Médici in the state of Rondônia, using 225 juveniles of tambaqui, with average initial body weight and length of 713.08g±0, 95 and 10.62 cm±0.1, respectively, being submitted to different feeding rates (0.5; 0.75; 1.0; 1.25 and 1.5% of body weight) with three repetitions each, in the density of 15 juveniles per hapa making a total of 15 hapas. Commercial feed of 28% crude protein was provided, and the fish were weighed every 30 days to adjust the feed supply in relation to body weight. The animals were slaughtered with an average of 2,162 g and 43.6 cm of total length at 140 days of culture. The intestine itself presented average weight and length between the batches of feed animals with different feeding rates of 7.7 g and 73.44 cm, respectively. The results of the biometric evaluation for weight and body length, weight and length of the intestine, relative weight of the intestine, CI:CC ratio (length of the intestine: body length) and the histomorphometric evaluation of the height of the intestinal villi did not present significant differences (P>0.05), however, there was a linear increase in the feeding rates (P<0.05) of tambaquis in the fattening phase for liver weight, from 27.77 g to 34.44 g, visceral fat weight, from 83.22 g to 121.63g, hepatosomatic index and viscerosomatic fat index, maximum 1.55% and 4.42%, respectively.