Probióticos na alimentação de juvenis de carpa capim (Ctenopharyngodon idella)

Abstract

The indiscriminate use of the growth promoters (antibiotics) at the animal feeding can result in development of resistant bacterial populations, determining instability in the symbioses between the desirable microbiota and the animal. In contrast, probiotics are alive microorganisms, that in latency mode (lyophilized) are added to the food and that benefits the development of the animals when they settle at the intestinal tract. Therefore, the objective of this study was evaluate the effect of the probiotic with Bacillus subtilis and Bacillus cereus in different amounts on the growth and hematological analysis of juveniles grass carp. The experiment was performed at the Aquariofilia Laboratory, on UNIPAMPA, Uruguaiana, RS, Brazil. It was used three doses of the probiotic mixed directly to the pelleted feed (T1 – Control, T2 – 5g/kg of feed, T3 – 10g/kg of feed and T4 – 15g/kg of feed), totaling 3 (three) treatments and 3(three) repetitions, during 56 (fifty six) days. Before the beginning of the experiment, 144 animals selected for this study were divided into 12 water tanks with 12 animals each - with initial average weight of 3.98 ± 0.7 g - where they were acclimated for 14 days, fed with 3% of body weight per day. As well, it was performed a total of five biometrics in order to assess the production data of the animals, among them, weight (g), total length (cm), survival rate (%),condition factor (%), average daily gain (g) and specific growth rate (%). At the end of experiment, it were measured the hematocrit (%) and the hemoglobin quantity (g/l). It was proceeded to ANOVA analysis followed by Tukey test to verify final means of production data and hematological parameters (p <0.05). The results indicated that there was no significant difference in the production data and it was not detected significant difference in the results of hemoglobin. Only in hematocrit analysis, T3 showed a significant increase compared to T1 and T2. Other studies are necessary, before providing the probiotic situations of high stress or periods of disease incidence (preventive action) in order to test the beneficial effects of probiotic against a stress stimulus.