The Evaluation of the Bio-Stimulator Potential of Some Fodder Additives Based on the Main Haematological and Biometrical of Brook Trout (Salvelinus Fontinalis M.)

摘要

The experiment was carried out between August December 2008 at the trout farm ICAS Gilau, situated in Cluj County on a number of 1000 juvenile brook troutes. The aim of this research was to elaborate a bio-mathematical model based on haematological, biochemical and biometrical indices, for the evaluation of the health status and the weight dynamics, conditions necessary for the quantification of the effects produced by the differential feeding and the supplementation of trout feed with fodder additives. Four groups were established: a Control group and three experimental groups (Bio-Mos 0.2 %, NuPro 2 % and SelPlex 0.03 %) each of them consisting of 250 juvenile brook troutes. At the beginning of this experiment the brook trout juveniles had an age of eight months, 20.2 g/fish and 12 cm in length. The experiment took place in four concrete tanks which offered the same rearing conditions. Every group received the same base diet, 41 % CP, 12 % Fat, 2,5 % Cellulose. Every experimental group received a different additive: ? Bio-Mos 0,2 % (bacteriostatic and stimulator of phagocitosis and immunity, extracted from Saccharomices cerevisiae) for group 2? NuPro 2 % (stimulator of the fodder consumption, made from free amino acids, glutamic acid, nucleotides and tripeptids) for group 3.? SelPlex 0,03 % (stimulator of several functions of the biological system of fish, component of the glutathione peroxidase, an enzyme that detoxifies the lipid peroxides and protects the cell membranes) for group 4.The haemogrammes were made for 7 fish from the group, the blood sampling was performed immediately after the brook trouts were captured. Blood samples were collected from the caudal vein using 2 ml disposable plastic syringe. The haematological investigations, based on known methods, included: microhaemotocrit (Ht), haemoglobin (Hb), the total count of erythrocytes (E), among the blood morphological exam on MGG blood smears. The correlation and the analysis of indices regarding the quantification of the health status (haematological indices) and the survival and losses, shows the beneficial biological effects of the additives that had been incorporated in the base diet of the brook trout. These effects are expressed through the normalizing effect noticed in the leucogramme and the diminished recorded losses. The evolution of individual and mean biometrical values showed the improvement of the total mass by 11,49 % in Bio-Mos 0,2 % group compaired to the Control group, this percentage was similar to the one reported by Staykov (2005) in rainbow trout (13,7 %). The values recorded in the other two experimental groups, NuPro 2 % and SelPlex 0,03 % were lower than the value recorded for the Bio-Mos group, although slightly higher than the one recorded at the Control group (93,57 g/specimen at SelPlex 0,03 % group and 94,1 g/specimen at NuPro group versus 93,5 g/specimen at the Control group).