The nutritional role of fishmeal in feeds is mainly to improve the balance of amino acid and protein utilization efficiency, compared with other raw materials has advantages, but the effect is not only the role of fishmeal advantages of its protein and amino acids, still unknown growth factor, vitamin, microelement etc. with nutritional advantage. Therefore, the technical aspects considered in the absence of fishmeal or low Fishmeal feed include the following aspects.
Balanced and effective amino acid
Protein nutrition is actually through nutritional effects of amino acids to achieve, therefore, in the absence of fish meal or treatment plus low fish meal feed is balance of amino acids. In the design of non fishmeal or low fish meal feed formula can choose meat meal, meat meal, soybean meal, rapeseed meal, cottonseed meal, by adjusting the ratio to achieve the balance of essential amino acids. However, the utilization of amino acids should be taken into consideration, that is, the effectiveness of essential amino acids. Although some raw protein content is very high, but the utilization rate is very low, such as feather powder, protein content of leather powder can reach more than 80%, but the digestion rate of only about 30%, either alone, or with fish meal (fishmeal), will make the effectiveness of essential amino acids in the formula significantly decreased. Therefore, when calculating the effect of essential amino acids balance, we should choose the feed ingredients with high digestibility to make the balance of essential amino acids as much as possible.
Of protein increases the oil saving
Fish for carbohydrate utilization effect is not significant terrestrial animal, mainly by amino acids and fat as an energy source, which is always the first one to meet the energy. When the fish meal is very low or the fish meal is not used, the use of fat must be increased to meet the energy requirement of fish, so as to improve the growth rate of fish. The choice of oil, including lard, butter, animal and vegetable mixed oil, soybean oil, vegetable oil and so on. Data show that the use of soybean and rapeseed oil, fresh rice bran provides better than pure oil feeding effect, therefore, conditional (rapeseed crushing, rice bran freshness keeping) the enterprises can choose these oils as a source of feed oil, the effect will be better. As the fat in the hard pellet feed reaches more than 7%, the powdering rate of the granules will increase significantly, so the level of grease in the feed should be controlled below 7%. In the required range, as much as possible with grease, such as control in 6% ~ 7%, you can get a good effect of farming.
Increase use of vitamins
Fishmeal with unknown growth factors, vitamins, trace elements and other components, to ensure the normal physiological function of fish fed in no fish meal or low fish meal feed conditions, can also be used to increase the amount of vitamin in the feed. Through several years of breeding experiments, it is found that it has a good effect on the protection of fish health and the protection of fish mucus. On the original level, a 20% ~ 30% increase in vitamin use will lead to better economic results.