KEY POINTS OF COMMERCIAL FEED FORMULATION FOR Litopenaeus vannamei IN CHINA
China have the biggest Litopenaeus vannamei culturing amount in the world (>100 million MT/Year) and fierce competition between feed mills lasting more than 20 years. Global governments, universities and feed mills together promoted the development of research on L. vannamei in aspect of increasing growth speed, improve the survival rate of the larval, decreasing the cost of formulation and so on.
Fish meal is one of the primary proteins in shrimp feeds because of its known nutritional and palatability characteristics. But fishmeal's high cost and concern about the reliability of future supplies from plant and animal by-product sources have prompted efforts to identify and develop novel and relatively cheaper ingredients to function as fish meal substitutes: Spray-dried blood meal, ultra-low gossypol cottonseed meal, peanut meal, insect meal, corn gluten meal. For example: Bacillus subtilis E20-fermented mixture containing soybean meal and Eisenia fetida earthworm meal can replace fish meal completely with same feeding efficiency. A maximum level of 140g kg-1 of peanut meal can be used in a commercial diet for the shrimp.
Lipid is of the highest energy density and many fatty acids from lipid metabolism are essential for normal growth and development of shrimp. EPA&DHA are essential fatty acid required by L. vannamei especially at early stage. Phospholipids and cholesterol are major constituents of membrane and are vital to the normal function related to ion permeability, can exert a modulating effect upon the activity of certain membrane enzyme systems and are essential.
About minerals, L. vannamei would have higher dietary magnesium (Mg) or potassium (K) requirement at low salinity, although marine species reared in seawater do not require dietary sources Mg and K. Because very low-salinity water will pose various negative effects.
Yeast is one of the probiotics, which is commonly used in aquaculture either alive to feed live food organisms, or after processing, as a feed ingredient. Yeast cells contain β-glucans, nucleic acid, oligosaccharides and polyamines, which may help to improve the immune response and growth performance as well as metabolism in L. vannamei.
This paper will give the detail evaluation of alternative protein ingredients with same performance but can decrease the cost of commercial formulation. Then essential elements requirement will be recommended like phospholipid, cholesterol and minerals when culture at low salinity. At last, this paper will describe the effect of yeast on the health of L. vannamei.