Influence of Some Fodder Additives (Bio-Mos and Nupro) on the Productive Performances and Health of Wels Catfish (Silurus glanis L.) Juveniles

Abstract

The goal of this research was to evaluate the effects of some fodder additives (prebiotic Bio-Mos 0.2% and proteic extract NuPro2%) on the growth performances and health of wels catfish juveniles expressed through some hematological and immunological indices. The researches had been made on 150 fish (Silurus glanis L.) from Budurleni Fish Farm, BistriŃa-Nasaud County, divided into three groups, 50 fish/group. At the beginning of the trial wels catfish juveniles had an age of 8 months, 110 g body weight and 20 cm body length. The experimental period was 150 days. Wels catfish juveniles were raised in a recirculating aquaculture system in controlled environmental conditions. The first group received in its fodder Bio-Mos 0.2% and the second one received in its fodder NuPro 2%. The wels catfish fodder had the following nutritional characteristics: 48.90% CP, 1.67% Cellulose, 11.13% Ash and 14.95% Cfat. The results obtained regarding the body weight evolution showed the positive effect of the fodder additives that have been incorporated in wels catfish juveniles feed, the Experimental group 1 reaching a higher body weight (+7.56% higher than the Control group). The growth rate and the specific growth rate showed an improvement at the experimental groups comparative with the Control group. The growth rate had been improved by 35.88% at group 1E and by 10.37% at group 2E. Also the specific growth rate of the experimental groups was improved by 36.84% at group 1E and 10.52% at group 2E as a result of diet supplementation with Bio-Mos 0.2% and NuPro 2%. At the end of the trial the feed conversion rate had lower values at the experimental groups (1.28:1) at group 1E and 1.30:1 at group 2E) comparative with the Control group (1.36:1) The results obtained are similar with the results reported by Bogut et al., 2006. At the experimental group 2E it was recorded the highest survival rate with 12% higher than the Control group survival rate. The benefic biostimulator effects of the fodder additives that have been incorporated in the basal diet of wels catfish juveniles had been assured through the maintenance in the normal range of the leukocitary indices and the lack of neutrophily (Caruso et al., 2002). Lysozime concentration increased at group 1E with 5.68 % comparative with the Control group, thus showing the imunostimulator role of Bio-Mos.