Rearing of rainbow trout in cages on warm waters with using the feed additive Sangrovit Extra

Abstract

Increasing the efficiency of feed with the use of different feed additives is becoming a particularly common method in aquaculture. Sangrovit Extra is a plant feed additive for increasing the productivity of farm animals due to the anti-infl ammatory and immunomodulatory properties of its components. The purpose of the research was to evaluate the effectiveness of the use of the Sangrovit Extra additive as part of trout compound feed in feeding rainbow trout when rearing in cages on the warm waters of the regional hydroelectric power plant. The object of research was individuals of rainbow trout. The introduction of the Sangrovit Extra feed additive in the amount of 400 mg/kg into the main diet of fish best contributed to the increase in the average daily gain of trout in cages by 0,48 g compared to the control group. The use of the studied additive contributed to the increase in the assimilation of feed, which was manifested in the indicator of its consumtion. When trout weighing 200–300 g were grown on the main diet (without additives), feed consumption per 1 kg of fish growth amounted to 1,26 kg, whereas when introduced into the feed in the amount of 100 mg/kg, 400 and 700 mg/kg, the efficiency of feed use increased by 9 %, 11 and 5 %, respectively. When rearing larger trout (1,2–1,5 kg), feed consumptions when using the additive in the amount of 400 mg/kg decreased from 1,47 to 1,36 kg, i.e. by 10,8 %. The use of the Sangrovit Extra additive when rearing commercial rainbow trout in cages on warm waters has shown the economic feasibility of its use, especially at the dosage of 400 mg/kg of feed. The level of profitability for rearing trout weighing 0,3 kg was 18,6 % higher, and for fish weighing 0,5 kg by 12,7 % compared to the control group.