PROBIOTICS STIMULATE MUSCLE GROWTH OF NILE TILAPIA Oreochromis niloticus

The objective of this study is to evaluate the effect of probiotic additive in tilapia growth, assessing the morphology of the muscular. Tilapia fingerlings of approximately 1.5 g were cultivated in recirculation systems containing 15 water tanks of 0.25 m³ each at 28 °C, with biological filter and UV system at 80 fish/m³. The fish are fed three times a day, with the same feed, using the probiotic additive supplied by Biomart Animal Nutrition. They were assessed the inclusion levels of 0.1 and 0.2% of probiotic additive. The probiotic was homogenized in 2% soy oil and sprinkled over the feed. The control treatment consisted only of the addition of vegetable oil in the same proportion. The histology of muscle was evaluated at day 30^th and 90^th of cultivation to quantify fibers muscle diameter. Fiber muscle were separated in different diameter class and plotted in a histogram. It was proceeded ANOVA and Multiple Comparison Procedures (Student-Newman-Keuls Method).

The muscle fiber diameter was higher with treatment with 0.1 or 0.2% of probiotic in relation to control. This occurred at days 30th and 90th of cultivation (Table 1). Actually at day 90^th of treatment with probiotics, the difference in relation to control was more intense than day 30^th (9.1% compared to 6.2%).

It was observed higher fiber frequency in the class 40-60 µm and smaller fiber frequency in the class >80 µm in control treatment when compared with treatment with probiotics (Figure 1). It wasn´t observed differences in hyperplasia (fiber < 20 µm). Probiotics added in diet stimulates muscle growth by white fiber hypertrophy.

Acknowledgments: Financial support was given by Fapesp.