Administration of medicated feed mixture with microsal in the case of carps bothriocephalosis in cage fish-farm

Abstract

The purpose of the research: to conduct tests of Microsal in composition of 2% medicated feed mixture, which can be prepared in the farm under new conditions of keeping fish in cages (ultimate extinction of heated discharge into heat sink and fish wintering in cages under ice). Materials and methods. Test of 2% medicated feed mixture was conducted at Cherepetskiy rybkhoz Joint Stock Company of Tula region on carp yearlings which were spontaneously infected by bothriocephalus. 4 experimental cages were selected at the 5th pontoon line where about 10 000 of yearling carps with average weighed quantity of 10 g were located. Total weight of fish in each cage was about 100 kg. Before medical and preventive fish processing from each testing cage off at 10 yearling carps had been caught and exposed to helminthological prosection to define extensity and intensity of fish infection by bothriocephalus. On the 6-th day after medical and preventive processing it was also conducted catching and helminthological prosection off at 10 yearling carps to define extenseffectiveness (EE, %) and intenseffectiveness (IE, %) of fish processing by 2% medicated feed mixture with Microsal. Results and discussion. Water temperature at the level of cages lines only by the end of May was 14.8°С because of cold spring. Content of solvable oxygen is 6.2 mg/l. Yearling carps by that time had tiny average weighed quantity and were greatly weakened. Fish infectiousness in cages No 5, 21, 25, and 36 was 40, 40, 50, and 40% respectively while average infection intensity of 1.25-2.0 cestode on one fish. After a single medical and preventive processing yearling carps by 2% medicated feed mixture with microsal (doses on AI 40 mg/kg) 100% processing efficiency was achieved in three cages. In the cage No 21 EE of deworming was 75.0% with intenseffectiveness 71.4%. For receiving high efficiency of medical and preventive fish processing in such type of cage fish farms it is necessary to increase the number of administration of medicated feed (3-5 times), whilst cutting content of microsal in medicated feed from 2% to 0.4-0.5%.