Effect of the probiotic Bacillus subtilis on growing, survival and fisiology in the bullfrog (Rana catesbeiana)

Abstract

The probiotics are live micro-organisms in latency state that benefit the development of the animals. The objective of this work was to evaluate the effect of the Bacillus subtilis in different doses on the growing, survival and immunological and hematological analyses in the bullfrog (Rana catesbeiana) froglets. The test was developed in Experimental Frog farm of Agriculture Department, Pindamonhangaba, SP. Three doses of probiotics were tested (T1 í  2.5 g/kg, T2 í  5 g/kg and T3 í  10 g/kg of food). The test was carried out with three simultaneous replicates, plus control group. The products were added to froglet´s diet, mixed to the meal. The animals were previously feed with this diet for a period of 14 days and accompanied for about 42 days after metamorphose. Biometrics was performed every 7 days. It was evaluated the final weight, the survival, phagocytic capacity, phagocytic index and hematological analyses as hematocrit, hemoglobin level, erythrocyte number, absolute hematimetric indices (MCV and MCHC), differential counting of leucocytes and total counting of leucocytes and thrombocytes. The results had shown that the doses of the probiotics had produced none effect on the final weight and survival. The immunological analyses had shown that the probiotics have presented immunostimulant effect, but have not influenced the hematological parameters of the animals.