PERFORMANCE EVALUATION IN THE GROWING OF THE STELLATE STURGEON FRY IN 35 DAYS FROM HATCHING UNDER THE CIRCUMSTANCES OF ENRICHENING FOOD WITH PROBIOTICS

Maria Desimira Stroe, V. Cristea , N. Patriche, Lorena Dediu, Magdalena Tenciu, Maria Cristina Chioveanu, Marilena Florentina Lăcătuş

Abstract
    The main objective of the present paper was to evaluate the influence of the commercial probiotic BetaPlus® Ultra on the growth performance of the stellate sturgeon after 35 days of hatching, but the specific objective was to evaluate the food retention efficiency in the transition period from feeding with natural feed to that with commercial feed. For this purpose, a 93-day experiment was carried out with 6 experimental variants (5 different probiotic concentrations: V₁-1.28x10¹³ CFU, V₂-2,56x10¹³ CFU, V₃-3.84x10¹³ CFU, V₄– 5.12x10¹³ CFU, V₅ -6.4x10¹³ CFU and V₆- control variant, in duplicates). The experiment started with a number of 6000 exemplars of 35-day post hatched larvae (500 specimens/rearing unit) with a mean individual weight (± SD) of 0.35 ± 0.02 g and a total length between 3-5 cm. According to the rearing technology, sorting was carried out throughout the experimental period which led to the division of the experiment into 9 different experimental stages according to feeding protocol.
    Feeding efficiency, expressed by FCR and protein retention, indicated by PER shows an insignificant increase (p>0.05) in the V2 variant and an insignificant decrease in the case where the probiotic (V₆) was not administered. Therefore, according to this experiment, a concentration of 2.56x10¹³ CFU / kg of commercial probiotic BetaPlus® Ultra represents an optimum value for promoting the growth, feeding efficiency and retention of proteins of trout after more than one gram.