Currently, the intensive aquaculture industry has two obvious characteristics: high-density releasing fingerlings and feeding fish with a large quantity of artificial formula feed. As is well known, artificial compound aqua feed is the primary nutritional source of intensive aquaculture, however, the heavy use of manufactured fish feed is also one of the main reasons that causes the pollution of aquatic water. In order to figure out the pollution problem of feed, people must control the source of pollution from a nutritional point of view, aiming at achieving the goal of green aquaculture.
Control the proportion of feed ingredients properly
When making the compound fish feed, some feed manufacturers always only consider the quantity demand for the protein of aquatic culture animals, but they ignore the demand for energy of aquatic animals, adding plenty of fish meal would lead to high phosphorus and high nitrogen, becoming the major reason for pollution. So when designing fish feed formulation, they need to promote the energy content of aqua feed and reduce protein content suitably, thereby alleviating the nitrogen pollution level caused by high protein nutrition.
Improve the biological value of protein
The massive nitrogenous substance, excreted by aquatic animals, is also a main factor leading to water body environment pollution, and these nitrogenous substances mainly come from undigested crude protein and amino acid in fish feed. Thus, adopting the ideal protein mode can improve the balance status of all kinds of amino acids in protein, enhance the biological utilization value of protein, effectively lower the level of crude protein in aquatic feed, promote the use ratio of nitrogen in feed, and reduce the excretion volume of nitrogen in excrement. This can not only save vast natural protein fish feed resources but also ease the degree of nitrogen pollution to the environment caused by intensive aquaculture.
Fair using the additional agent
The fair use of some additional agents, to some extent, could improve the quality and flavor of fish feed, promote the ingestion of aquatic animals, increase the operation rate of fish feed, and then mitigate the pollution degree to the water body environment.
Peptide pharmaceutics: Peptide is a high-efficiency biologically active substance without drug residue, which will not bring resistance to drugs. In order to lower fish feed costs, it is necessary to add a certain amount of plant raw materials when making aqua feed. After using peptide pharmaceutics, people can not merely improve the palatability of fish feed, but also roundly accelerate the digestion and absorption of nutrient ingredients in fish feed to boost the efficiency of feed utilization, hence greatly decreasing the excretion volume of nutritive materials (like organic matter, nitrogen and phosphorus, etc.) in aquatic animals excrement, and reduce the pollution to water environment brought by undigested substances in fish feed.
Efficient mineral substance: Mineral substances are an essential kind of nutrient material in aquatic animals’ life activity and aquaculture production process. Even if fish can assimilate some mineral matter from the water environment, it still cannot satisfy the growth requirement, so fish farmers have to supplement a certain quantity of mineral substance in fish feed. However, some people still stay in the stage of using inorganic salt as mineral matter additional agent, which would easily lead to volume of addition increasing continuously and bring more and more severe environmental pollution. Tests indicate that using the organic salt form as the mineral substance can raise the utilization factor of mineral matter, cut down its additive amount in feed, relieve the pollution of the water environment, and lower production costs.
Improve processing technic
Fish feed producing technology (such as grinding, mixing, extruding and so on) can affect the avaliability of aquatic animals feed nutrient, so when producing fish feed, people should adopt the corresponding processing technologies to make high quality fish feed suitable for fish to eat and digest, according to the various life habits, diverse growth stage and physiological function of different kinds of fishes.
At present, it is the inevitable tendency for the feeding stuff industry and aquaculture industry healthy growth by developing aqua feed with low pollution, and it is also the precondition to relieve the vicious circle between aquaculture and the environment and produce pollution-free aquatic products. All in all, the application of fish feed with low pollution will become the development direction of the aquaculture industry in the future.
Choose an advanced fish feed machine
The fish feed making machine plays a quite significant role in producing high-quality fish feed without pollution. For example, aqua feed made by fish feed extruders has the following several obvious advantages: high water stability, convenient to control feed density, uneasy to smash and more healthful.
To be specific, water stability is an important index for fish feed, and promoting feed water stability is quite necessary, especially for eating slower fish, shrimp, crab, and so on. If with bad stability in the water, there is not enough time for those aqua animals to ingest food before feed decomposes, which not only wastes fish feed but pollutes water quality, going against environmental protection and sustainable development of aquaculture. Moreover, it is convenient to control feed density by producing floating feed and sinking feed to meet different aquatic aniamls ingesting need. Especially adopting the floating pellet, it is also easy for fish farmers to observe fish eating conditions, saving feed and reducing waste. Due to the good mechanical properties of fish feed extruder machine, it is not easy for fish feed to smash. Any smashing of finished products before usage would generate dust, increasing feed waste and polluting air and water as well. Besides, feedstuff would be through high-temperature processing, equal to pasteurization process, which can kill all harmful germs, reducing the water pollution caused by noxious bacteria.
