Key Technical Points for Grass Carp Farming in the High-Temperature Season
Grass carp is one of the main freshwater fish farmed in China, known as one of the Four Major Chinese Carps, and has extremely high economic value. July to September each year is its peak growing season, but it is also one of the hottest periods of the year. If management is inadequate at this time, mass mortality of grass carp can easily occur, causing huge economic losses to farmers. So how should grass carp be farmed during the summer high-temperature period? Let's take a look with Qinnong Web.
1. Water Quality Management
During the summer heat, the water level of the fish pond should be raised appropriately to achieve a cooling effect; otherwise, if the water level is too low, the self-regulation capacity of the water body declines, which can easily trigger stress responses in grass carp, increase the outbreak rate of disease, and cause death of the grass carp. Therefore, in summer the water level should be raised to about 2.5 m, and must not be lower than 1.5 m. Water quality testing should also be done well, testing the water quality once a week to ensure it is good and suitable for grass carp growth. Once the water quality deteriorates, it should be adjusted promptly or the water should be changed directly, keeping the fish school in a comfortable water environment in the pond.
2. Aeration
As is well known, fish survive through the dissolved oxygen in the water body. During farming, due to site limitations and high stocking density, insufficient dissolved oxygen often occurs, which can suffocate grass carp to death. The summer heat easily creates a muggy environment, so aeration is a necessary measure during the high-temperature period. There are generally three methods for aerating the water body: one is natural dissolution of oxygen from the air, the second is aeration through plant photosynthesis, and the third is aeration through artificial aerators. In summer, the first method is unsuitable, and the second has major limitations; for example, at night there is no sunlight, so phytoplankton cannot produce oxygen and instead even consume the dissolved oxygen in the water body. Therefore, in summer, artificial aeration is generally carried out.
3. Scientific Feeding ⟹9⟧During the summer high-temperature period, grass carp have low activity, generally lurking in the cool shaded areas at the bottom of the pond, and their appetite is also poor, so feeding methods must be handled with care. The bait fed must be fresh, and the proportion of fine feed must be increased. During the day, when the temperature is higher, the grass carp will basically not eat much after feeding, which not only causes waste but also easily causes the bait to ferment and deteriorate, polluting the water quality. The number of feedings per day should be increased, feeding 3-4 times a day, with morning and evening as the main feeding times, and a small amount can be fed during the day. Among these, the proportion of fine feed in the evening should account for 60%-80% of the whole day's fine feed ratio, so that after eating, the grass carp can rest, which can promote rapid fattening.
In summer, when temperatures are high, grass carp (Ctenopharyngodon idella) have low activity levels and generally lurk in the cool shaded areas at the bottom of the pond, and their appetite is also poor, so special attention must be paid to feeding methods. The bait fed must be fresh, and the proportion of fine feed must be increased. During the day, when temperatures are higher, the grass carp will basically eat very little after feeding, which not only causes waste but also easily leads to the bait fermenting and spoiling, thereby polluting the water quality. The number of feedings per day should be increased, feeding 3-4 times a day, with morning and evening as the main feeding times, and a small amount can be fed during the day. Of this, the proportion of fine feed in the evening should account for 60%-80% of the whole day's fine feed ratio, so that after eating, the grass carp can rest, which can promote rapid fattening.
4. Disease Prevention and Control
Summer is a season with a high incidence of disease, so disease prevention and control work must be done well, adhering to the principle of "prevention first, prevention more important than treatment," and targeted treatment should be carried out after disease occurs. You should be familiar with and understand the characteristics of several common summer diseases, and make a decision immediately after the disease occurs. If it is impossible to determine which disease it is, you should promptly communicate with professional technical personnel and, under their guidance, apply targeted medication for prevention and control.
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