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Techniques for large-scale rearing of bream summer fry, suitable for triangular bream and blunt snout bream
Bream (triangular bream, blunt snout bream) are high-quality freshwater fish. They are not only excellent species for pond culture but also suitable for stocking in large water bodies, where their tendency to readily form natural populations can be used to achieve resource protection and enhancement. The techniques for large-scale rearing of bream summer fry are described below: 1. Conditions of the summer fry rearing pond. The summer fry rearing pond requires an abundant water source, unpolluted water quality, and convenient filling and drainage. The area should not be too large, generally 1-3 mu, with a water depth of 1-1.2 m being suitable. The pond must not leak,
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A Detailed Guide to the Main Diseases of Large Yellow Croaker and Their Prevention and Treatment Methods
I. Bacterial Diseases 1. Vibriosis Pathogen: Vibrio parahaemolyticus. Symptoms: The appearance of ulcers on the body surface of diseased fish is the typical feature of this disease. In the early stage, there are petechiae, ecchymoses, and irregular red patches on the body surface, mostly seen on the abdomen and tail. In severe cases, there is bleeding and ulceration of the lower jaw, congestion and redness at the fin base, missing fin rays, and rotting of the caudal peduncle muscle, forming hemorrhagic ulcers. The liver, spleen, kidney, and intestine are all congested, the liver is enlarged and earth-yellow in color, and there is pale yellow mucus in the intestinal tract. Microscopic examination of the tissue at the lesion site reveals slightly curved bacteria. Epidemiology: This disease
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Prevention and Control Methods and Technical Key Points for Protozoan Diseases in Large Yellow Croaker
(1) Pathogen: Cryptocaryon irritans (Crypjocaryonirrions). (2) Symptoms: Small white spots appear on the body surface and gills of diseased fish. These small white spots are white vesicles formed by the parasitism of the parasite, irritation of the host, and the secretion of large amounts of mucus and proliferation of epidermal cells in the surrounding tissues. In severe cases, the body surface tissues are destroyed. If bacteria invade, it can cause skin inflammation, scale loss, fin membrane rot and splitting, corneal damage, and blindness. The diseased fish ultimately die due to loss of appetite,
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Prevention and Control Methods and Technical Key Points for Common Diseases of Large Yellow Croaker
I. Cryptocaryon irritans disease (white spot disease) Symptoms: A large number of small white spots appear on the body surface. In severe cases, the fish body is covered with a layer of white film. Due to the destruction caused by the parasites, secondary bacterial infection is triggered, resulting in inflammation and necrosis of the fish epidermis, scales easily falling off, fin rays rotting and splitting. When parasitizing the gills, it destroys the gill filaments, and after bacterial infection, it causes gill rot. When the parasites invade the fish's cornea, it causes inflammation and blindness. Diseased fish have reduced appetite, become thin, and swim erratically. The parasites can be identified by microscopic examination. Prevention
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Detailed Explanation of Key Techniques for Transplanting Large Suckling Pear Trees
1. Selection of trees for transplanting Any pear tree without serious pests or diseases can be transplanted, but practice has shown that selecting younger trees (under 20 years old), with lower trunks and relatively complete crowns, results in a higher survival rate. 2. Treatment of trees for transplanting Before transplanting, saw off diseased and pest-infested branches, branches positioned too high, excessively dense large branches at the base, and transitional branches between layers, while appropriately retaining lower scaffold branches, small branches under 2 years old, and branches in better positions. In September, root pruning should be carried out on the large trees to be transplanted, so that they form callus tissue
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Feeding and Management Key Points for Large Yorkshire Sows During Their High-Production Period
1. The age structure of the sow herd must be reasonable. According to a survey of 150 litters from parities 1-10 at a certain pig breeding farm in Jining, sow production performance varies with age (parity). The Large Yorkshire sow is a fine breed with relatively stable genetic traits, a long high-production period, strong reproductive capacity, and sustained high and stable production over many years. According to a survey of 150 litters from parities 1-10 at a certain pig breeding farm in Jining, adult sows (parities 4-7) averaged 12.4 live piglets born per litter, which is 1.6 more per litter than young sows (parities 1-3)
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What are the prevention and control methods for abdominal distension and ulceration disease in large yellow croaker?
(1) Pathogen According to reports from Japan, it is Vibrio alginolyticus; but another source says it is Edwardsiella. (2) Symptoms The stomach sac of diseased fish is especially swollen and enlarged, and in some fish the dorsal and ventral walls rupture from the swelling, with the entire stomach sac detaching from the fish body. Large numbers of diseased fry float scattered on the water surface, unable to feed, spin in circles for several days, then sink and die. Larvae at 15-20 days of age are most susceptible, showing a peak mortality period. (3) Prevention and control methods Increase the water exchange rate, improve the rearing environment, avoid feeding Artemia nauplii alone, feed copepods earlier, strengthen the nutrition of larvae and juveniles, and strictly control water quality.
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Large-scale leaf-rolling of the central leaves of rice may be related to excessive application of quinclorac
For some time recently, hundreds of readers across our province have called to report large-scale leaf-rolling of the central leaves of rice seedlings, which is even more common in direct-seeded rice production. Many readers brought in diseased plants. The root systems of the diseased plants are generally fairly normal, and there are no obvious disease spots or other symptoms on the leaves. After examining the submitted diseased plants, relevant experts from the Institute of Plant Protection of the Provincial Academy of Agricultural Sciences and other units preliminarily diagnosed that the leaf-rolling of the central leaves of rice is not caused by viruses or other pathogenic microorganisms, but may be phytotoxicity caused by herbicides such as 2,4-D and quinclorac, or may be caused by physiological
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Introducing the characteristics of the new large peach variety Hongfurong
Hongfurong giant peach is a mid-to-late ripening variety. In the Beijing area, the flowering period is in mid-to-late April, and it can be harvested in early August, with a whole growth period of about 110 days. It has extremely strong storage tolerance; the harvested peaches can be kept at normal temperature for 20 days without spoiling or rotting, making it most suitable for long-distance transport. The peaches are especially large, with an average fruit weight of 420 g and a maximum of up to 1210 g. The appearance is gorgeous; after the fruit ripens, it is nearly round with a flat top, the suture line is obvious, the peach fuzz falls off naturally, and the fruit surface is pink. The flesh is milky white, dense, and hard-melting, with a strong
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Detailed Explanation of Key Technical Points for Rearing Large Silkworms in Autumn
The main reason for the instability of autumn silkworm production is the damage caused by silkworm diseases. As the number of silkworm rearings increases, the number of pathogens increases, the spread area expands, and the viruses are fresh and multiply quickly, resulting in a high disease rate. After repeated use of silkworm rooms and silkworm tools, if disinfection is not thorough and rearing management is relaxed, combined with the harsh environment of high temperature and high humidity or high temperature and dryness in autumn, as well as the poor quality of mulberry leaves, the silkworms have weak disease resistance, all of which are the main reasons for the easy outbreak of silkworm diseases during the large silkworm stage in autumn. 1. Strengthen disinfection and disease prevention, eliminate pathogens. The effective measure to prevent silkworm diseases is disinfection, eliminating
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