Inclusão de plantas daninhas: Caruru-de-espinho (Amaranthus spp.) e Grama-Seda (Cynodon dactylon (L.) Pers ) na ração comercial para Tilápias-do-Nilo (Oreochromis niloticus) /

Abstract

This study aimed to assess the level of inclusion of weeds: caruru-de-espinho (Amaranthus spp.) and grama-seda (Cynodon dactylon (L.) Pers) about the performance of the fingerlings tilápia-do-Nilo (Oreochromis niloticus). The treatments consisted in different experimental diets with the weeds caruru-de-espinho (Amaranthus spp.) and grama-seda (Cynodon dactylon (L.) Pers) incorporated into commercial feed in the proportion (0, 20, 40 and 60%). It was adopted a completely randomized design with 04 treatments and 05 replications, totaling 20 experimental units with a capacity of 130 liters each, with 10 fishes, weighing about 35.76 g and average size of 12.45 cm in each experimental unit during 45 days. Were performed biometrics of initial weight to homogenize the samples, and every 15 days, new biometrics were made to adjust the feed and check the effects of treatments on the performance of the young. The animals were fed with the experimental diets which were given twice daily (9:00 and 15:00). During the experimental period, were assessed weekly the physicochemical parameters of water, pH and electrical conductivity, and daily, temperature and dissolved oxygen. The treatments did not affect (P> 0.05) for the physicochemical parameters measured and final body weight, final size, growth and survival, however, the fingerlings of tilapia-do-Nilo fed without weeds, showed a higher gain of total weight in relation to other levels of inclusion. There was a linear decrease with the inclusion of the weeds in the diet. Water quality did not change in relation to the physicochemical characteristics with the inclusion of weeds in the diet of fingerlings tilapia-do-Nlo, however, animal performance was reduced.