The journal of modern fisheries reports:
The term "feed" coefficient in aquaculture industry can be seen everywhere, the meaning of the expression and the feed conversion or feed remuneration, refers to the breeding objects to increase the unit weight consumed by the weight of the feed. Mathematical expressions for aquaculture objects: feed feed (kg)/fish and shrimp (kg) by 100% (1).
In the present, many feed users, or salesmen, use the feed coefficient as an important indicator of the price performance of a feed product. This is true in nature, but it often leads them to the wrong thing. What is the reason? I don't understand the concept of the feed factor.
Many people have long thought of the feed coefficient: feed intake (kg)/fish and shrimp (kg) (kg) by 100% (2)
Analysis: the above algorithm is fully formed when the survival rate is 100 percent, when the fish is in a pond, and the fish is hundreds of thousands of tails. However, in the process of a build fish/shrimp farming fish in death is inevitable, in fact loss in the process of breeding fish/shrimp also consumed a feed, and in the end when he sold fish and shrimp pond is calculated when everyone always ignored the weight of this part of the fish/shrimp, as a result, the feed coefficient calculation value is artificially increased.
The actual feed coefficient measuring mathematical expressions: feed feeding amount (kg)/(final fish and shrimp harvest + dead fish and shrimp weight - miao initial weight) (kg) x 100% (3).
Let's say the feed feed is WF, the fish and shrimp harvest is WH, the dead fish and shrimp are the WS, and the initial seedling weight is W0.
The problem: in sewer system and bottoms of shrimp aquiculture Gao Weichi, for example, in actual production, the few farmers will believe fish/shrimp of daily sewage died while weighing, the final feed coefficient is how to calculate out of? Note: the calculated value of the feed coefficient must be established on the basis of the survival rate is extremely high, means that Ws this factor can be neglected in the formula, and the initial settlement seedling weight relative to the quantity of fish and shrimp harvest Wh on numerical is also small, negligible, can directly calculate by formula (2) sets.
The factors affecting the feed coefficient are worth analyzing:
A small number of meals is better than the concentration. As is known to all, a few much food feeding way is more advantageous to the aquatic animals will feed nutrition into their nutrition, relative to the concentrated feed, can save more fish and shrimp feed was too late to eat in water soluble loss and waste. In addition, fish and shrimp in a specific phase of the feeding amount is relatively fixed, if artificial feeding, more than fish and shrimp feeding amount that part of the feed directly will be wasted, namely WF in formula (3) increase, and the final is a general calculation, certainly will raise the feed coefficient values.
The amount of natural bait in the water
When water quality is fat, cultivating natural bait will be more, will be rich in the early breeding of fish bait, but in the short term, fish or shrimp were domesticated feeding after perfect compound feed, natural bait in food composition proportion is negligible. In theory, part of the natural bait would have lowered the feed coefficient, but the effect was negligible.
Farmers most profound understanding of this point, the breeding cycle short, shrimp head is big, in the case of high survival rate, feed coefficient value is generally low, relative to the long-term feeding and the fish is long speed slow, use the formula (3) analysis shows that equivalent to the first kind of circumstance of WF and the WS value is reduced, and WH value increases, the feed coefficient value is reduced, the result and the whole building WuBingHai fish and shrimp farming, there is a close relationship between high quality seedlings and feed.
Death caused by disease or external circumstances
Because many farmers in the production of death was not for the individual weight or simply do not consider, then appear fish death phenomenon will make the feed coefficient value increases. But the scale of the increase is divided into two aspects: the occurrence of intensive death is in the early and late middle stage.
Assuming a pond shrimp seedlings: 100000 breeding 20000 10 days before the date of death, since the feed feeding amount is small, actually we can treat as only this pond seedlings 80000 tail to feeding, so as long as breeding later don't appear intensive death, for final estimates feed coefficient value is slightly on the high side, but with the real value is more close to. In succession and the fish in the middle on a wide range of death, although the feed quantity of feeding the appropriate adjustments, but yield WH reduced, and the increase, at this time if you do not consider when selling fish and shrimp in the clear pond WS, feed coefficient value will significantly increase. This is the reason many farmers have blamed the failure of the final feed coefficient on the poor quality of the feed, and the fact that the method is wrong.
This article is from the tongxin community (http://www.tongwei.cn/).