Measures for Promoting Fattening of Grass Carp in Autumn Farming
Autumn is the peak season for grass carp to put on weight. Doing a good job of feeding during this period can increase production by about 30% compared with normal management. Specifically, the following measures should be carried out well:
1. Regulate water quality, add new water to increase oxygen. First, add new water to increase the dissolved oxygen content in the water. Generally, add new water 7 to 20 times per month, with each addition lasting 1 to 2 hours, and the amount of water added should preferably account for 5% to 10% of the whole pond. Second, splash quicklime, which can both increase calcium and disinfect and sterilize. Generally once every 10 to 15 days, for a pond with a water depth of 1 m per mu, use 15 kg to 20 kg of quicklime dissolved into slurry and splash it in sections twice.
2. Fertilize the water quality and improve the environment. The autumn climate is a key period suitable for the growth and development of grass carp. At this time, more topdressing should be applied to cultivate the water quality. Generally, apply 300 kg to 400 kg of pig and cattle manure per mu of water surface, or 2.5 kg to 3 kg of urea and 4 kg to 4.5 kg of superphosphate, to ensure that the fish have enough biological bait, so as to help accelerate the accumulation of nutrients and maintain a good growth environment.
3. Feed concentrate to promote body growth and fattening. In autumn, the temperature drops noticeably, and the zooplankton and organisms in the water decrease. In order to meet the feeding needs of grass carp and make up for the shortage artificially with concentrate (made from leftover rice powder, rice bran, wheat bran, soybean powder, peanut bran, etc.), feed once a day, and the daily requirement of concentrate accounts for 3% to 4% of the total feed. Starting in October, it should be appropriately increased to reach 5% to 9%.
4. Feed green feed, with a mix of coarse and fine. Before feeding concentrate, green feed should be fed first, namely green grass, vegetables, etc., and every effort should be made to keep it fresh, tender and green, and free of pollution. Achieve fixed timing, fixed quantity and fixed location. Each feeding should be finished within 3 small meals. In order to increase appetite, a variety of green feeds can be fed in rotation to promote development and rapid growth.
5. Observe frequently to prevent floating head. Entering autumn, for fish ponds with high intensive culture density, due to excessive feeding and fertilization, the water contains a lot of organic matter and oxygen-consuming factors increase, while fish activity is also frequent. In order to avoid oxygen deficiency and floating head, patrol the pond frequently every morning and afternoon, especially at night.
6. Prevent and treat fish diseases, grow quickly and fatten. In autumn, large-sized grass carp eat and grow voraciously and are prone to enteritis and gill rot, etc. Bleaching powder hanging baskets can be used at the feeding site, with each basket containing 50 g to 100 g of bleaching powder and 100 g to 150 g of 95% crystalline trichlorfon, hanging 2 to 3 baskets per mu of water surface for 5 to 7 consecutive days. At the same time, remove the residue in time and only use deteriorated bait to feed the fish. In addition, attention should also be paid to eliminating snakes, algae and other harmful organisms in the pond to avoid damage and affect the fattening and development of grass carp.