Water hyacinth has been discovered as a viable option according to study carried out by Dr. S. A. Vhanalakar and Dr. D. V. Muley, Department of Zoology, Shivaji University, Kolhapur, India showing the benefits of water hyacinth as fish feed ingredient.
Water hyacinth is one of the most highly productive plants filling up a small area within a short time span as is considered the world's worst aquatic weed. It forms dense mats that interfere with navigation, recreation, irrigation and power generation. These mats competitively exclude native submerged and floating-leaved plants.
The rising cost and scarcity of fish meal has prompted studies to find alternatives to the fish meal by using locally available and cheaper ingredients of either animal or plant origin. The success of the aquaculture industry depends worldwide on the availability of low cost, high quality feeds to break even.
In the past several studies were carried out to look for substitutes for fish meal in the fish feed.
Fish nutritionists have evaluated alternative sources of plant origin protein in fish diets as partial or total fish meal replacement. Water hyacinth has been found suitable among other options,as it was found to replace the fish meal at various levels of inclusion without any side effects but rather an increase in fish productivity.
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The study carried out using the common carp fed for 120 days. : fresh water hyacinth leaves were collected from local water bodies, these were washed thoroughly with water to remove dirt and debris and drained properly before sun drying.
The dried leaves of water hyacinth were milled , packed in airtight polyethylene bags and kept in the freezer before use.
The inclusion of the dried leaves in the feed was at different rates ranging from (0-70%), groundnut cake, rice bran, fish meal, guar gum binder and mineral/vitamin mixture were all added to formulate the feed.
Ingredients were mixed until an homogeneous mass was obtained and with the mincer 0.6 mm pellets were prepared, which were immediately sun dried. The dried pellets were broken up by hand into convenient pellet sizes and frozen before feeding the fish.
The water hyacinth diet showed the great usefulness as fish feed ingredient and for cost effectiveness.
The feed with 40% water hyacinth incorporated diet showed best growth performance over all the other inclusion rates, although all the diets containing the water hyacinth leaf powder showed effectiveness as an economic fish feed .
Water hyacinth does not have the capacity to replace the traditional fish meal,therefore, it is used as a supplementary fish feed ingredient along with the traditional ingredients; but the incorporation level of traditional ingredients like fish meal, groundnut cake, rice bran etc. was kept at lowest inclusion level.
Water hyacinth can play an important role in fish feed formulation to overcome high feed prices.
