Zootechnical effects of different levels of prebiotics and probiotics in diet of Nile tilapia fingerlings

<p>This study evaluated the effects of symbiotic inclusion on the zootechnical performance of Nile tilapia. For this purpose, fry with an initial weight of 2.48 ± 0.53 g were used and fed until the juvenile stage (16.31 ± 1.7 g). The experiment, conducted over 53 days at UFGD—Federal University of Greater Dourados, followed a completely randomized design with five treatments and four replicates. The diets contained different levels of symbiotics (1.5%, 3.0%, 4.5%, and 6.0%), in addition to a control group without additives. After the final biometric measurements, the liver, intestine, and visceral fat of three fish were analyzed to determine the visceral fat index, intestinal quotient, and hepatosomatic index. Additionally, performance parameters such as final weight, weight gain, feed conversion ratio, batch uniformity, and survival were evaluated. Data were subjected to analysis of variance (ANOVA) after tests for homogeneity and normality. No significant differences in zootechnical performance were observed between treatments. Thus, under the conditions of this study, the inclusion of symbiotics did not show benefits compared to the control group and is not recommended for improving the performance of Nile tilapia fry.<strong></strong></p>