Feed management of major carps in India, with special reference to practices adopted in Tamil Nadu
Résumé
In India, major carps, namely catla (Catla catla), rohu (Labeo rohita) and mrigal (Cirrhinus cirrhosus) dominate aquaculture production. Although Chinese carps such as common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella) and silver carp (Hypothalmichthys molitrix) are cultured, their popularity in the market remains low. In some of the emerging commercial culture systems Chinese carps are almost excluded due to marketing and other management constraints. Due to the non-availability of compounded feeds, the majority of farmers in most parts of the country continue to depend on a conventional mixture of rice bran and oil cake as the common supplementary feed. Application of manures and inorganic fertilizers to produce natural food is widely used, even when compounded feeds are employed. With the increased commercialization of carp farming and greater market focus, demonstration of the commercial viability of the use of pelleted feeds is undertaken by feed companies. With a number of innovations made by farmers in evolving suitable culture practices and feeding methods, pelleted feeds are gaining acceptance in some parts of the country.However, although carp farmers desire to use compounded pelleted feeds, due to the highly dispersed nature of carp farms they are confronted with problems in obtaining feeds in small quantities. Faced also with difficulties in obtaining compounded feeds at an affordable cost, farmers have no option but to continue to use rice bran as the major feed input along with oil cakes, even in states like Andhra Pradesh where carp culture is well organized. In Punjab, where a feed manufacturing factory is located, a competitive pricing policy exists; an effective marketing strategy has been adopted by the company and a high percentage of farmers have switched to the use of pelleted feed. In Tamil Nadu, another state where carp farming has gained popularity, particularly in areas such as Thanjavur District where water is not a major constraint, farmers have begun to realize the benefits of feeding floating pellets. However, availability and delivery to farmers are major constraints hindering the expansion of pellet feed-based carp culture in the state. In this review, an attempt is made to present the general feeding strategies adopted in different parts of India, with a specific case study drawn from the State of Tamil Nadu where farmers have demonstrated the benefits of using floating pellets. The review also covers the current status of feed ingredient availability, the feed manufacturing industries and the strategies that need to be evolved to promote compound feed-based carp culture. A major part of the information used in the preparation of this paper was gathered via a countrywide survey on the feeds and feeding practices used in the culture of Indian major carps