The Use of Two Bifidobacterium Strains Enhanced Growth Performance and Nutrient Utilization of Rainbow Trout (Oncorhynchus mykiss) Fry

Abstract

This study aims to evaluate the effects of Bifidobacterium animalis PTCC-1631 and Bifidobacterium lactis PTCC-1736 on growth, nutrient digestibility, carcass composition, and intestinal microbiota of Oncorhynchus mykiss fry, which had initial body weights of 0.58 ± 0.19 g. Four iso-nitrogenous diets with probiotics, namely T (1 × 10 CFU g), T (2 × 10 CFU g), T (3 × 10 CFU g), and control without probiotics were obtained. Total 480 fish were randomly divided in four treatments (three experimental treatments and a control), each with 4 replicates including 16 tanks each filled with 15 L of water (water exchange rate of 2 L min and aerated with air stone) with a density of 2 fry L. The water mean temperature was 17.66 ± 1.33 °C, and the mean pH value was 7.63 ± 0.08. After eight weeks of the experiment T that fed with a diet contained the lowest bacterial concentration showed higher growth, nutrient utilization, digestibility, and lower feed conversion ratio (P < 0.05) in comparison with T2, T3, and the control. Also, the highest count of lactobacillus bacteria was observed in T that was fed with a diet containing the lowest probiotic. The lowest concentration of Bifidobacterium strains in this study induced better growth and increased digestion and nutrient utilization in trout fry.

The Influence of Probiotics of Different Microbiological Composition on Histological Structure of the Organs of the Gastrointestinal Tract of Juvenile <em>Oncorhynchus mykiss</em>

“…The results confirm the influence of probiotics on histological structure of intestine and liver tissues. The studies of the use of probiotics on Oncorhynchus mykiss have been conducted by many scientists using various species of microorganisms [8,12,18,25,26]. According to the authors, the use of probiotics is reasonable only when natural intestinal microflora needs correcting and for improvement of digestibility of feed with unbalanced composition [3,27].…”

“…Probiotic preparations were used in the experiment after microbiological studies confirming the composition and the accordance of quantity of bacteria with the stated numbers. The control group of species received feed without additives, the experimental groups received feed with probiotic preparations of various microbial composition in the number determined by other studies on trout and other species of fish [10,18,21,22].…”

Multistrain probiotics use in main commercially cultured freshwater fish: a systematic review of evidence

“…The surveillance of the selected probiotics in the gastrointestinal tract was followed only in a few publications in the present review. Methodologies used to evaluate the detection of the probiotic included culturedependent plate counting (Bagheri et al 2008;Giannenas et al 2015;Standen et al 2015;Standen et al 2016;Sahandi et al 2019), culture-independent fluorescent in situ hybridization, polymerase chain reaction-denaturing gradient gel electrophoresis and high-throughput sequencing (Del'Duca et al 2013;Ramos et al 2013;Standen et al 2015;Adeoye et al 2016;Oz orio et al 2016;Standen et al 2016;Hao et al 2017;Ghori et al 2018;Xia et al 2018). Some of the articles detected the administered bacteria in the intestinal tract.…”

Probiotics for cultured freshwater fish

“…Most of the journal articles sourced suggested the use of probiotic concentrations of approximately 1 Â 10 6 CFU/g of feed showed significant improvement in growth performance, resistance to infection, and immune modulation. Growth performance and health status improved in trout 11 , and tilapia 12 , with a probiotic microbial concentration around 1 Â 10 6 CFU/g of feed.…”

“…Oncorhynchus mykiss 11 and Salmo salar 10 . Bhujel et al 16 used regression analysis to define the optimal concentration of the two commercial probiotic formulations in Labeo rohita, showing that the effective dosages were higher concentrations than that suggested by the manufacturers.…”