How do aquaculture farmers choose aquatic feed scientifically
First of all, through sensory indicators, relying on vision, smell, taste and touch to judge the quality of feed. The color of the feed is uniform, without mildew, deterioration, agglomeration, or insect damage; the smell of the feed is normal, without rancidity, burning oil, etc.; the shape and size of the particles are uniform, there is no crack on the surface, and it is water-resistant.
2, according to the size of aquatic animals, choose the appropriate feed particle size. This can ensure the effective feeding of aquatic animals and avoid the waste of feed. Taking fish as an example, the selected feed particle size is generally in the range of 1/4 to 2/3 of the longitudinal length of the fish mouth crack, and the length-to-diameter ratio of the feed should also be determined according to the specific cultured species, generally between 1.5 and 2.5:1 .
3, in the choice of feed grade, the balance point of breeding is the main basis. If the price of a single kilogram of fish in the fish fry wholesale market in Chongqing does not exceed the feed cost of a single kilogram of fish farming, low-grade compound feed should be used; if the price per kilogram of fish is higher than the feed cost per kilogram of fish, compound feed should be selected. Generally, the higher the feed grade, the higher the cost performance.
4, in terms of feed performance, it is necessary to choose feed, pay attention to the growth performance of aquatic animals after feeding feed, pay attention to the feed coefficient and how to ensure the health of aquatic animals. The feed has the following characteristics: low feed coefficient, fast growth and low disease incidence.
5. Misunderstandings that should be paid attention to when choosing
1. When choosing, only pay attention to the price of feed, and deliberately pursue low-priced feed. Low-priced feed tends to discount the quality of the feed, the growth cycle is long, and the feed coefficient is high. Although the price of feed is high, it can shorten the breeding cycle, thereby reducing the risk of breeding and the cost of water and electricity management caused by the long cycle. The middle and late stages of aquaculture are often the period of high incidence of diseases. For example, the cultivation period can be shortened, the risk of disease can be greatly reduced, and the overall cultivation efficiency can be improved. Feed cost is affected by feed factor and feed price. The formula for calculating feed cost per unit weight of aquatic products is: feed unit price (yuan/kg) feed coefficient. Sometimes changes in feed factor have a greater impact on feed cost than changes in feed price. Therefore, when choosing feed, we should start from the overall farming cost and benefit, pay attention to the farming cost per ton of aquatic products, pay attention to the feed coefficient, and choose feed.
2. It is believed that feed with high protein level has good breeding effect. This is a one-sided and unscientific point of view. Protein is only an important nutrient for aquatic animals, not everything. In the case of the same protein source, the growth effect of aquatic animals increases with the increase of protein level, but after exceeding this level, the growth performance no longer increases or shows a downward trend. Excess protein is a metabolic burden for aquatic animals. In addition, the quality of protein is determined by the composition ratio and quantity of its amino acids. At the same protein level, the amino acid composition of different protein sources is quite different, resulting in large differences in growth effects. For example, fish meal and soybean meal, at the same protein level, the growth effect of feed with fish meal as protein source is better than that with soybean meal as protein source. Therefore, the quality of feed should be evaluated based on protein level, other nutritional levels and raw material sources.