Fermentation of Plant-Based Feeds with Lactobacillus acidophilus Improves the Survival and Intestinal Health of Juvenile Nile Tilapia (Oreochromis niloticus) Reared in a Biofloc System.

This study evaluated the effect of fermentation with Lactobacillus acidophilus on the biochemical and nutritional compositions of a plant-based diet and its effects on the productive performance and intestinal health of juvenile Nile tilapia (Oreochromis niloticus) reared in a biofloc technology (BFT) system. The in vitro kinetics of feed fermentation were studied to determine the L. acidophilus growth and acidification curve through counting the colony-forming units (CFUs) mL-1 and measuring the pH. Physicochemical and bromatological analyses of the feed were also performed. Based on the microbial growth kinetics results, vegetable-based Nile tilapia feeds fermented for 6 (FPB6) and 18 (FPB18) h were evaluated for 60 days. Fermented diets were compared with a positive control diet containing fishmeal (CFM) and a negative control diet without animal protein (CPB). Fermentation with L. acidophilus increased lactic acid bacteria (LAB) count and the soluble protein concentration of the plant-based feed, as well as decreasing the pH (p < 0.05). FPB treatments improved fish survival compared with CPB (p < 0.05). Fermentation increased feed intake but worsened feed efficiency (p < 0.05). The use of fermented feeds increased the LAB count and reduced pathogenic bacteria both in the BFT system's water and in the animals' intestines (p < 0.05). Fermented plant-based feeds showed greater villi (FPB6; FPB18) and higher goblet cell (FPB6) counts relative to the non-fermented plant-based feed, which may indicate improved intestinal health. The results obtained in this study are promising and show the sustainable potential of using fermented plant-based feeds in fish feeding rather than animal protein and, in particular, fishmeal.

Fermentation of Soybean Meal with Lactobacillus acidophilus Allows Greater Inclusion of Vegetable Protein in the Diet and Can Reduce Vibrionacea in the Intestine of the South American Catfish (Rhamdia quelen).

The objective of this study was to evaluate the effect of diets containing different inclusion levels (0%, 7%, 14%, 21% and 28%) of soybean meal fermented by Lactobacillus acidophilus (SMFL) on the zootechnical performance and intestinal health of South American catfish juveniles (Rhamdia quelen). The experimental design was completely randomized with five treatments and four replications and lasted 56 days. Five isoproteic (39% crude protein) and isoenergetic (4300 kcal of gross energy kg-1) diets were formulated where SMFL was included in replacement of fish meal. Two hundred forty South American catfish juveniles (3.0 ± 0.5 g) were distributed in 20 tanks (70 L) connected in a recirculation aquaculture system. At the end of the experiment, the inclusion of SMFL up to 21% in replacement of fish meal did not affect the zootechnical performance and also decreased the concentration of Vibrionaceae bacteria present in the intestine compared to the control group. The amount of total lactic and heterotrophic bacteria, the enzymatic activity and the intestinal morphometry did not differ between dietary treatments. The results demonstrate that fermentation with Lactobacillus acidophilus enables greater inclusion of soybean protein in South American catfish diets and promotes the control of intestinal pathogenic bacteria.

Densidade de estocagem e restrição alimentar em juvenis de piapara / Stocking density and food restriction of piapara juvenile

The effects of stocking density and food restriction in juvenile piapara (Leporinus elongatus) were studied by two experiments. In the first, 88 piaparas juveniles were stocked in three densities (0.13, 0.20 and 0.40 fish L-1) for 70 days. Were evaluated: weight gain, average consumption, specific growth rate and feed conversion. The experiment was conducted in completely randomized design with three treatments (0.13, 0.20 and 0.40 fish L-1) and four replicates. In the second experiment, 84 fish were divided into three treatments (RBD, with 4 replicates): control group (daily food); FDS group (animals fed on weekends) and Res 21 group (animals subjected to food restriction for 21 days). Highest stocking density resulted highest biomass produced. Fish subjected to food restriction for 21 days and animals fed on weekends group, displayed full compensatory growth.(AU)

Foram avaliados os efeitos da densidade de estocagem e da restrição alimentar em juvenis de piapara (Leporinus elongatus) por meio da realização de dois experimentos. No primeiro, 88 juvenis de piaparas foram estocados em três densidades durante 70 dias. Foram avaliados: ganho de peso, consumo médio, taxa de crescimento específico e conversão alimentar. O experimento foi conduzido em DIC, com três tratamentos (0,13; 0,20 e 0,40 peixe L-1) e quatro repetições. No segundo experimento, 84 peixes foram divididos em três tratamentos (DBC, com quatro repetições): grupo controle (alimentação diária); grupo FDS (animais que não receberam alimento aos finais de semana) e grupo Res 21 (animais submetidos à restrição alimentar em 21 dias consecutivos). No primeiro experimento a maior densidade de estocagem resultou na maior biomassa produzida. No segundo experimento, em relação ao manejo alimentar, os animais submetidos à restrição alimentar em 21 dias consecutivos e os animais que não recebiam alimentos aos finais de semana, apresentaram crescimento compensatório total após a realimentação.(AU)

Densidade de estocagem e restrição alimentar em juvenis de piapara / Stocking density and food restriction of piapara juvenile

The effects of stocking density and food restriction in juvenile piapara (Leporinus elongatus) were studied by two experiments. In the first, 88 piaparas juveniles were stocked in three densities (0.13, 0.20 and 0.40 fish L-1) for 70 days. Were evaluated: weight gain, average consumption, specific growth rate and feed conversion. The experiment was conducted in completely randomized design with three treatments (0.13, 0.20 and 0.40 fish L-1) and four replicates. In the second experiment, 84 fish were divided into three treatments (RBD, with 4 replicates): control group (daily food); FDS group (animals fed on weekends) and Res 21 group (animals subjected to food restriction for 21 days). Highest stocking density resulted highest biomass produced. Fish subjected to food restriction for 21 days and animals fed on weekends group, displayed full compensatory growth.

Foram avaliados os efeitos da densidade de estocagem e da restrição alimentar em juvenis de piapara (Leporinus elongatus) por meio da realização de dois experimentos. No primeiro, 88 juvenis de piaparas foram estocados em três densidades durante 70 dias. Foram avaliados: ganho de peso, consumo médio, taxa de crescimento específico e conversão alimentar. O experimento foi conduzido em DIC, com três tratamentos (0,13; 0,20 e 0,40 peixe L-1) e quatro repetições. No segundo experimento, 84 peixes foram divididos em três tratamentos (DBC, com quatro repetições): grupo controle (alimentação diária); grupo FDS (animais que não receberam alimento aos finais de semana) e grupo Res 21 (animais submetidos à restrição alimentar em 21 dias consecutivos). No primeiro experimento a maior densidade de estocagem resultou na maior biomassa produzida. No segundo experimento, em relação ao manejo alimentar, os animais submetidos à restrição alimentar em 21 dias consecutivos e os animais que não recebiam alimentos aos finais de semana, apresentaram crescimento compensatório total após a realimentação.