Reducing the death of cull broodstock is an important technical task for fish fry producers. In production practice, we found that there are two causes of the death of broaching broodstock: First, the broodstock consumes a lot during physical reproduction, and the side effects of oxytocin drugs make the broodstock body's resistance to decline, if the fish is injured. Severely, various pathogens will take the opportunity to invade the fish body, causing disease, leading to the death of the broodstock; Second, the broodstock is poor in physical condition, the gonadal development is poor, or the water temperature changes during the evacuation is large, and the dosage of the oxytocin drug is improper (dose Too high or too low), the broodstock cannot spawn properly or produce dystocia, and this can cause disregard of their own physiological activities and lead to death. Therefore, the production must focus on the care work before and after oxytocin production.
First of all, it is important to attach importance to fishing operations. This is an important part of reducing broodstock casualties. Whether in the broodstock pond or in the spawning pool, the nets should be lightly and coherently coordinated. The nets will be quickly collected on the shore as soon as they reach the shore. From the shore, avoid brooding fish hitting a wall. When there is a high temperature on sunny days and the fish transportation distance is long (distance between the brooding pond and the spawning pond), it is better to choose to fish in the early morning or early evening, and to prevent the brooding fish from lacking oxygen in the stretcher.
Second, when the broodstock is pulled from the spawning pool, inspections should be carried out one by one. All female abdomen with enlarged abdomen must press the abdomen by hand to help it produce mature eggs in the abdomen; if the broodstock suffers from dystocia due to plugging of the genital pores, it is necessary to cut the blocked genital hole with a sterilized surgical scissors. Enlargement allows mature fish eggs to be excreted from the body. This will prevent mature fish eggs from swelling in the body of the broodstock and endanger the broodstock (this is one of the major causes of post-partum death of female broodstock). For broodstock with wounds on the body surface, the wound should be wiped dry with a cotton wool ball, and then washed with potassium permanganate solution or malachite green solution containing 1% salt, and then use the fingers from the tail to the head against the direction of fish scales. Apply sulfa ointment or erythromycin, tetracycline and other anti-inflammatory ointment to the wound; on the body surface, there are brooded, swollen and sore brooders. Dry the lesion with a cotton wool ball first, then apply iodine and apply an anti-inflammatory ointment. For bred broodstock, either 1 ml of sulfa drugs (containing 0.2 g of drug) or their other anti-inflammatory drugs are injected every 5-8 kilograms of body weight regardless of injury.
Ponds that store bred broodstock must be sterilized with fresh lime ponds. The pool water should be fresh and the water depth should be about 1.5 meters. After the broodstock is released, the broodstock should not be treated with organic fertilizer for the first month. Regular bleaching, strong chlorine, fish and shrimp safety and other drug solutions must be used to disinfect and prevent fish diseases. The broodstock begins to feed at about 5 days in the lower pool and is mainly fed with gluten buds, malt, alfalfa cakes or compound feeds for broodstock, and grass broodstock should be fed with appropriate amount of fresh green grass. Usually 3 to 5 days to replace part of the pool of new water, regulate water quality, stimulate the appetite of broodstock, make it quickly recover and enhance resistance.
First of all, it is important to attach importance to fishing operations. This is an important part of reducing broodstock casualties. Whether in the broodstock pond or in the spawning pool, the nets should be lightly and coherently coordinated. The nets will be quickly collected on the shore as soon as they reach the shore. From the shore, avoid brooding fish hitting a wall. When there is a high temperature on sunny days and the fish transportation distance is long (distance between the brooding pond and the spawning pond), it is better to choose to fish in the early morning or early evening, and to prevent the brooding fish from lacking oxygen in the stretcher.
Second, when the broodstock is pulled from the spawning pool, inspections should be carried out one by one. All female abdomen with enlarged abdomen must press the abdomen by hand to help it produce mature eggs in the abdomen; if the broodstock suffers from dystocia due to plugging of the genital pores, it is necessary to cut the blocked genital hole with a sterilized surgical scissors. Enlargement allows mature fish eggs to be excreted from the body. This will prevent mature fish eggs from swelling in the body of the broodstock and endanger the broodstock (this is one of the major causes of post-partum death of female broodstock). For broodstock with wounds on the body surface, the wound should be wiped dry with a cotton wool ball, and then washed with potassium permanganate solution or malachite green solution containing 1% salt, and then use the fingers from the tail to the head against the direction of fish scales. Apply sulfa ointment or erythromycin, tetracycline and other anti-inflammatory ointment to the wound; on the body surface, there are brooded, swollen and sore brooders. Dry the lesion with a cotton wool ball first, then apply iodine and apply an anti-inflammatory ointment. For bred broodstock, either 1 ml of sulfa drugs (containing 0.2 g of drug) or their other anti-inflammatory drugs are injected every 5-8 kilograms of body weight regardless of injury.
Ponds that store bred broodstock must be sterilized with fresh lime ponds. The pool water should be fresh and the water depth should be about 1.5 meters. After the broodstock is released, the broodstock should not be treated with organic fertilizer for the first month. Regular bleaching, strong chlorine, fish and shrimp safety and other drug solutions must be used to disinfect and prevent fish diseases. The broodstock begins to feed at about 5 days in the lower pool and is mainly fed with gluten buds, malt, alfalfa cakes or compound feeds for broodstock, and grass broodstock should be fed with appropriate amount of fresh green grass. Usually 3 to 5 days to replace part of the pool of new water, regulate water quality, stimulate the appetite of broodstock, make it quickly recover and enhance resistance.