Background:
Ensuring the food security and nutritional quality to the growing human population, it is essential to intensify the aquaculture. Farmers are exploiting the compensatory growth potential of fish by rearing them in high stocking density and restricted feeding and subsequent ambient rearing condition. The stunted fingerlings raised in this way helps to provide seeds throughout the year and reduce the culture period to save the cost of production. Attaining compensatory growth will not only reduce the culture period, but also reduce expenditure on feed, which constitute more than 40% of the total cost of production. However, attaining compensatory growth depends on the intensity of stress exposure and there can be partial, full, over or no compensation based on the stress intensity. This is mainly because of the changes in physiology of the animal due to the stress exposure. Stressors like high stocking density and feed restriction can alter the physiology of fish and create a condition called “no-point of return” in which the fish cannot compensate when provided a comfortable environment. Moreover, the stress exposure can decrease the immunity of the fish and results in outbreak of diseases leading to reduced growth and production. Most of the time the key factor behind this is the uncontrollable production of reactive oxygen species (ROS) during the general adaptive syndrome (GAS). Hence, stimulation of the antioxidant defense by externally providing the non-enzymatic antioxidant will be a new and innovative strategy. Studies showed that the non-enzymatic antioxidant are the first line of defense which individually and or with the enzymatic antioxidants neutralizes the ROS and protect the fish from adverse effect. Thereby promote growth and health of the fish. Therefore, synergistic effects of a few non-enymatic antioxidant mixture was evaluated in relation to growth and immunity enhancement and stress mitigation during stress exposure and compensatory growth were studied in Labeo rohita to develop CIFE Vrudhhi.:
Technology Details:
Feed cost share the major recurring expenditure in aquaculture farms and contribute significantly to decide the cost of aquaculture production. Feeding of fish according to its requirement can reduce wastage of feed and thereby reduce the cost of production. Sometimes, frequent feeding may not be essential to satisfy the requirement of the fish. Hence, it is crucial to adopt an appropriate feeding strategy which reduces the feed wastage, enhances the feed utilization, production and profitability. In this context, exploitation of compensatory growth of fish offers a possibility of high growth rate with minimum feed input through strategic feeding schedules of diet restriction and satiation feeding. In India, carp culture system utilizes the advantages of compensatory growth by rearing the fishes in two phases such as a stress phase or stunting phase with overcrowding and feed restriction followed by re-alimentation with ad libitum or satiation feeding to catch up or recover or compensate growth. But, crowding or over stocking and feed restriction are considered as chronic stressors in aquaculture which causes higher reactive oxygen species (ROS) production leading to oxidative stress. Though there is an efficient antioxidant defense system present in fish, the spontaneous production of reactive oxygen species (ROS) due to stress factors like crowding, feed restriction etc. can reduce the stress mitigation efficiency of the cells during the compensatory growth phase. This leads to an increased concentration of ROS, which is detrimental to fish health and growth. Dietary intervention by providing additional non-enzymatic free radical scavengers is a potential strategy to stimulate the entire antioxidant defense system of the fish for mitigating the oxidative stress effects. The present invention of a vitamin-mineral based nutritional formulation is such a non-enzymatic free radical scavenger which reduces the detrimental effect of stress and enhances the growth in compensatory phase of carps at 0.1 - 0.5% inclusion level in the diet. Therefore, methionine, zinc, selenium and vitamin E based nutraceutical conglomerate is proposed for commercialization in the name of CIFE Vruddhi.