During fish farming, fish feed cost accounts for over 60% in the whole fish farming cost. Compared with land animals, fish owns more special living environment – water environment. Water would cause the nutrition loss of feed, increasing breading cost. Except for providing high-performance fish feed production line and aquatic feed making machine, FANWAY Fish Feed Machinery is also committed to researching how to promote the utilization ratio of fish feed, in order to save aquaculture cost and help fish farmers get more profits. On the basis of scientific breeding, this article explains three points about fish feed use efficiency improvement, including “what to feed”, “feeding amount” and “how to feed”, and in a word, called “precise combination”.
Precise combination is a feeding technology used under the condition of benefit maximization, close to the best feeding rate. That is to say, when feeding fish, fish farmers need to efficiently control the feeding amount, frequency, time, place, feeding mode and other technical points. In the meantime, combined with fish specification, water quality and fish price, fish farmers should precisely breed fish with suitable fish feed in the form of combination.
What to Feed – choose suitable fish feed (grade, type and grain size)
The choose of fish feed grade: there are lots of fish feed with various types and different prices, so many fish farmers are confused about which type of feed should be chosen for breeding fish. Generally speaking, the choose of feed should follow the principle that the nutritional level of fish feed should be matched with the nutritional requirement of fish species.
1．Fish feed grade choose
1)For the same type fish, the nutritional requirement at the stage of juvenile fish is always higher than that of adult fish stage, so FANWAY suggests to choose higher grade fish feed for juvenile fish while lowering the feed grade a bit for adult fish. For example, for grass carp, fish farmers can choose fish feed with high protein content (crude protein should be not less than 33%) for young fish, and feed adult grass carp with a bit lower grade fish feed with not less than 30% crude protein content.
2)Different breeding species also decide different choice for feed grade. Here is the requirement for nutrition of various fish species in accordance with degree_descending: carnivorous fish, omnivore fish, herbivorous fish. For instance, the crude protein amount required by crucian is higher than grass carp.
3)Feed grade choice also depends on fish price. For high price fish, farmer can choose higher grade fish feed to breed, shortening time to market and improving culturing benefits.
2. Fish feed type choose
In the market, there are 3 major types of fish feed: sinking pelleted fish feed, floating extruded fish feed and sinking extruded fish feed. The extruded processing for fish feed can reduce bacteria, mycete and fungus content, improving the sanitary quality of feed. Meanwhile, extruding process is in favor of enhancing the protein valence of feed and increasing the heat value of fat. But sometimes extruded feed exists some problems, like bad irritability, hence, FANWAY suggests match sinking pelleted feed and floating extruded feed together to use according to the ratio of one to one.
3.Fish feed grain size choose
Based on the most suitable foraging theory, fish are always inclined to ingest the bait containing maximum capacity but spending the least time. Therefore, fish feed grain size should be as large as possible under the premise that fish can digest. In the actual production, the choose of fish feed particle size is mainly affected by fish, and usually, fish farmers can produce the feed pellet with various grain sizes through using fish feed extruder machine with different press molds.
Feeding Amount – the determination of feeding rate
Feeding rate, the percentage of feed weight(put in water) accounting for farmed fish weight, is closely related with fish weight and water temperature. For one same fish species, feeding rate at young fish is higher than that of adult fish. Besides, within the scope of appropriate water temperature, the higher water temperature, the higher feeding rate.
From the practical experience, feeding amount should be controlled in 70%-80% full, which not only means seventy-eighty percent of feed amount, but also means seventy-eighty percentage of farmed fish amount can eat their fill while others cannot, aiming at keeping farmed fish with good appetite and promote feeding efficiency.
How to Feed – feeding method, frequency and time
- Feeding method: The common feeding methods contain spreading by hand, self-help feeding and bait casting machine feeding. Therein, spreading by hand is flexible to use, accurate and concentrated, easy to observe and energy saving, quite suitable for small and medium size fish farm with adequate work force and for rare and special aquatic farming; self-help feeding means fish gets feed by touching bait casting machine, which is appropriate for aquaculture model with big breeding density and small breeding area, such as net cage or circulating water; bait casting machine feeding method has the advantages of fixed time, fixed quantity and fixed position, time-saving and labor-saving.
- Feeding frequency is related to the peculiarity of fish digestive organs. For stomach-less fish(like cyprinoid, crucian, grass carp and so on), the feed directly enter intestines for digestion after intake, which makes its feed intake at a time much less than carnivorous stomach-containing fish, so feeding times of stomach-less should be higher than stomach-containing fish. In addition, because the peptic of adolescent fish has not been well developed, leading to its absorbing ability inferior to adult fish, so feeding times of young fish should be much higher.
There is a principle to follow when feeding fish at the fixed position, “slow-fast-slow and few-many-few”. Three minutes before feeding, it’s better to adopt low frequency feeding and feeding area is about one-third of normal, after most of fish concentrating, fish farmers should spread breeding area and adopt normal frequency feeding. And 5 minutes before ending feeding, farmers should slow down the breeding frequency.
- Feeding time and position: Fish farmers can arrange the feeding time at the period between two hours after sunrise and time before sundown, choosing the time with good appetite, water quality and water temperature. While the feeding location should be chosen at place with sunniness, deep water, high dissolve of oxygen(over 3mg/l) and 5m-8m far away from pond bank.
Summary about feeding technology:
- Choose fish feed with not less than 30% crude protein content for grass carp and crucian; choose 3.0mm grain size feed for 100-200g grass carp and crucian, while choose 5.0mm for the two fish over 200g.
- The budget of feeding amount is quite accurate. Based on general feed coefficient, testers can calculate the growth vigor of fish, combining with water temperature, count the respective feeding amount of carp and crucian, then get the feeding table of whole culture period. Showing as follows:
- Feeding position and feeding times should be fixed, 4 times per day, and feeding time is: 8:00am, 11:00am, 14:00pm and 18:00pm.