The relationship between koi intake and koi weight gain is well known, fish eat less food and definitely grow slower, but how much slower the fish grows after eating less food is not something that every fisherman knows. Fish eat feed, digest and absorb most of it, and not all of this digested and absorbed nutrition is used for weight gain. Fish in order to maintain life and activities, every moment to consume nutrients, these consumptions include basic metabolic consumption, that is, to maintain the basic metabolic consumption of life; activity metabolic consumption, that is, the fish's normal swimming, foraging, avoiding enemies, avoiding damage to the escape, etc. Consumption of body heat gain, the fish ingested the metabolism of the process need to be increased by the additional consumption; resistance to pathogen attacks, injuries and illnesses when repairing damaged tissues; resistance to harsh environmental consumption. consumption; consumption of resistance to harsh environments, etc. Most of these expenditures occur even when fish do not feed.
Some experts test, with the aquarium feeding weight 3.2 ~ 3.4g of Nile tilapia, 5 groups, water temperature of about 25 ℃, through the air and micro-flow water supplement oxygen, satiation without residual bait to feed, the protein source of the feed for casein or egg albumin, sugar source for alpha starch and dextrin, fat source for corn oil, digestive energy density 15.9 ~ 19J / kg, digestibility of crude protein 96 ~ 98%, in the With this high quality feed and excellent feeding conditions, Nile tilapia use only 55 to 62% of the protein fed for growth, and roughly 40% of the protein is used for life support and activity.
Under the condition of outdoor ponds, with the use of high quality feed normal feeding and normal intake of fish, the digestibility of the feed is only about 80%, feeding feed only 25-30% of the protein for the growth of fish. Considering the effects of various factors, it is generally true that 20% of the main nutrients in the feed consumed by the fish will be digested and become part of the feces excreted, 30% of the protein will be used for growth, and 50% of the protein, basically all the absorbed carbohydrates, and most of the fats or some of the fats will be used for life support and activities. This is the normal eating situation. If a fish's eating is cut in half, is the fish's weight gain likewise cut in half? No. Instead, it is basically consumed only for life support and activity, and no weight gain or only a slight weight gain, or possibly even a weight loss, is possible.