Probiótico autóctone (Enterococcus faecium) na frequência de alimentação de larvas de piauçu Megaleporinus macrocephalus (GARAVELLO & BRITSKY, 1988) sobre o desempenho produtivo e resistência à patógenos

Abstract

The study evaluated the effect of dietary supplementation with brine shrimp enriched with the autochthonous probiotic Enterococcus faecium on productive performance, microbiota modulation, and resistance to the pathogenic bacteria of piauçu larvae Megaleporinus macrocephalus. The experiment evaluated six treatments, carried out in a completely randomized design in a 3 x 2 factorial scheme, consisting of three feeding frequencies (2x, 3x and 4x) and two diets (I without probiotic) and (II with probiotic) in five repetions, provided via nauplii. of brine shrimp. The larvae (n= 300; weight = 5.2 ± 2.6 mg and length = 3.69 ± 0.4 mm) were distributed in 30 1 L recipients at a density of 10 larvae/L1 for 20 days. At the end of the experiment, the indexes of productive performance, survival and microbiology were measured. 120 specimens were acutely challenged against Aeromonas hydrophila. The results showed significant interaction (p<0.05) with the highest means of length gain (14.42 ± 0.45 cm) and total weight (0.06 ± 0.02 g) for the frequency of 4x.day (diet II) supplemented with probiotic, higher counts of lactic acid bacteria (7.23±0.07 log CFU.g-1 - diet II) and higher counts of total heterotrophic bacteria (5.46±0.07 CFU.g -1 – diet I) in the intestines. Diets containing probiotics influenced the resistance of animals in acute infection, with lower accumulated mortality in the 4x.day - diet II group (26.66 ± 16.54%), and higher in C+ (100 ± 14.35 %). Thus, probiotic supplementation with the autochthonous bacterium Enterococcus faecium (1.0 x 108 CFU.g-1), at a frequency of 4x.day, provides zootechnical improvement, microbiota modulation and greater resistance to pathogenic infection.