Krzysztof Wunderlich, Mirosław Szczepkowski, Michał Kozłowski, Bożena Szczepkowska, Iwona Piotrowska
ABSTRACT. The aim of the experiment was to determine the impact adding a vitamin-mineral supplement to feed had on selected rearing indexes of juvenile common whitefish (Coregonus lavaretus) during rearing in a recirculating system. The study material comprised juvenile common whitefish aged 4 months with an initial body weight of 5.2 g and body length of 7.6 cm. During the experiment, the feed applied was extruded juvenile feed T – 1.5 Nutra MP Trouv (France). The experiment comprised two dietary treatments: group K (feed without a supplement) and group M (feed with a vitamin-mineral supplement). The feed supplement used was the MIK 1 mixture (Mikita, Lublin-Zemborzyce). The quantity added was 10% of the extruded feed. During the experiment, significant differences were noted in fish growth and the feed conversion coefficient (P < 0.05). Individuals with body deformities were noted during the experiment; the deformities manifested primarily as the shortening of the operculum and mouth anomalies. The number of these individuals differed in the two groups, and by the end of the experiment the number of individuals with body deformities in group K was significantly higher (13.8% of all fish) than in group M, in which such deformities were noted in just 1.3% of the fish (P < 0.01). Based on the results, it was concluded that through the application of the vitamin-mineral supplement higher biomass growth was attained, feed conversion was better, and the number of fish with body deformities was lower. Thanks to this, the rearing results of juvenile common whitefish in recirculating systems was more effective.
Keywords: common whitefish, feed, growth, deformation
Przyjęto po recenzji 15.09.2010 r.