Crocodile is a wild animal with high scientific research value, ecological value and economic value, belonging to reptiles, crocodiles and crocodiles. There are 3 families, 8 genera and 23 species of crocodiles in the world. Crocodiles are all treasures, and their meat, bones, nails and internal organs are rich in high-quality protein and essential amino acids, unsaturated fatty acids, vitamins and various trace elements. Crocodile bile has the functions of detoxicating, relieving fever, removing nebula and promoting metabolism, and can be used to treat bone cancer, liver cancer, bladder cancer, central retinitis and food poisoning, especially fatty liver and liver cirrhosis. In Thailand, a big crocodile breeding country, crocodile gall is very cherished and regarded as a panacea for treating female infertility and irregular menstruation. Crocodile liver has the functions of nourishing brain, promoting blood production, removing dampness, nourishing yin and liver, and improving eyesight, and can be used to treat senile cataract and vision loss. Crocodile heart, combined with Radix Notoginseng and Radix Salviae Miltiorrhizae, can nourish the heart, soothe the nerves, promote blood circulation and remove blood stasis, and treat angina pectoris, myocardial hypoxia and coronary heart disease. Crocodile bone can treat and prevent rheumatic bone pain. Crocodile bone powder contains a lot of active calcium and phosphorus, which can be used to treat osteoporosis in the elderly and calcium deficiency in children. Crocodile tail glue can not only nourish liver and kidney, enhance cell vitality, but also protect and beautify skin, increase skin elasticity, reduce and delay the early appearance of wrinkles, and also have satisfactory effects on allergies. Crocodiles have always been loved by consumers. However, due to the low requirements for the growth environment of crocodiles, some farms have polluted water bodies and poor water quality, and the quality of feed is problematic, which leads to poor growth of crocodiles, affecting the quality of crocodile meat, and some have odor, which seriously affects the reputation of crocodiles. In view of this situation, since 2002, we have carried out research on crocodile healthy breeding technology in Zhenshan crocodile breeding base and Sihui science and technology demonstration field built by Guangdong Zhenshan crocodile breeding Co., Ltd., aiming at discussing the technical measures, methods and effects of crocodile healthy breeding, providing healthy and pollution-free food for the society and ensuring the health of the people. Practice has proved that the effect is obvious and the method is feasible, which is worth popularizing.
Crocodile breeding base is located in the mountain tourist area of Sihui Town, Guangdong Province, with an area of 400 mu. During the implementation of this research project, all crocodiles were fed with autotrophic and fresh feed fish (tilapia, silver carp and bighead carp), and the fish ponds were regularly injected with new water. Feed fish (tilapia, silver carp, bighead carp) are raised by themselves, and unified feeding management is implemented. The results showed that the crocodile meat in the market was delicious, sweet and crisp, which met the epidemic prevention standards, food hygiene and safety standards and international pollution-free food requirements. Moreover, crocodiles grow fast, with high yield and good economic benefits.
I. Methods
1. The correct location crocodile breeding base is located in the tourist area of Shishishan, Sihui Town, Guangdong Province. Zhenshan Tourist Area is the only provincial-level tourist attraction in Sihui. The whole Zhenshan tourist area is dominated by sightseeing and ecological agriculture, and agriculture is dominated by pollution-free vegetables, flowers and pollution-free aquaculture. The factory has no "three wastes" discharge, and the environment in the whole region is excellent, without industrial pollution, pesticide pollution and domestic pollution. Sufficient water, good water quality, fresh air and no pollution in soil. The fish ponds in the crocodile breeding base have fertile soil, sanitary environment and fresh air. The newly injected water is Zhenshan mountain spring water, which is absolutely pollution-free and fresh, completely meeting the requirements of pollution-free and pollution-free farming.
2. Fish pond facilities
(1) Crocodiles are cultivated in mud ponds with a total area of 225 mu. The area of each pond is 1-2mu. The bottom of the pond is flat, the silt is ≤20CM, and the water depth is 1-1.5m. There is a fence1m high around the fish pond to prevent crocodiles from running outside and outsiders from entering. The ratio of water surface to land area in the fence is about 1: 1, which is beneficial to the growth of crocodiles.
(2) Feed fish (tilapia, silver carp and bighead carp) are cultured in earthen ponds, with a total area of1.65mu, with an area of 8 8- 10/0mu per pond, flat bottom, silt ≤ 20cm and water depth of1.5-2m.
3. Crocodile species selection The main crocodile species are Siamese crocodile, Nile crocodile and bay crocodile.
4. After cleaning the pond and disinfecting the dry pond, use quicklime to clean the pond and disinfect it before releasing the seedlings to adjust the water quality.
5. The water monitoring base should set up a quality control working group to be responsible for quality and safety monitoring. In particular, strict control measures should be taken for the surrounding environment of aquaculture waters in the base. The quality control team of the base should pay close attention to whether the spraying of pesticides, water sources and water quality changes in the surrounding farmland will cause harm to aquaculture production in the base, and fishery administration and environmental protection departments should actively cooperate. Once a pollution accident is found, remedial measures should be taken in time to prevent the production of the base from being affected. We entrusted the Guangdong Provincial Fishery Quality Supervision and Inspection Center to conduct the "Environmental Quality Assessment Report of Pollution-free Agricultural Products Origin" on the water body and surrounding environment of the base. According to the report, the aquaculture water quality in this base meets the Water Quality Requirements for Pollution-free Food Freshwater Aquaculture (NY505 1-200 1).
6. Selection of fry ① The body is healthy and disease-free, and the crocodile seedlings that have passed the inspection propagate themselves or are imported from Thailand for stocking. ② Choose healthy and disease-free tilapia, silver carp, bighead carp and other fry for stocking.
7. Stocking density: put 200-300 alligator seedlings with a body length of 30- 100 cm (3- 10 kg) per mu, and the stocking density of feed fish (tilapia, silver carp and bighead carp) shall be carried out as usual, with big fish caught and small fish kept.
8. Feeding methods
① Crocodiles are all fed with their own fresh feed fish (tilapia, silver carp and bighead carp), and the fish ponds are regularly replenished with fresh water. Catch the big ones and keep the small ones, that is, if the crocodiles reach more than 30 kilograms per tail, they will be caught, processed and listed, and if they fail to meet the listing specifications, they will continue to be classified.
② The feed for tilapia, silver carp and bighead carp is mainly compound feed, corn and wheat bran. Scientific feeding, regular addition of quicklime, beneficial microorganisms and water quality improvers, equipped with an aerator and a water pump to increase oxygen and change water. Catch the big ones and keep the small ones, that is, catch crocodiles that meet the feed specifications and provide them as feed, and continue to breed them in grades if they fail to meet the requirements.
9, daily management measures
The management mode adopted in the base is that all crocodiles are fed with self-bred fresh feed fish (tilapia, silver carp and bighead carp), and the feed is fed and managed in a unified way. Be responsible for training the staff of the base on the technical regulations of crocodile healthy breeding production and providing technical guidance services, focusing on key links such as water quality control, seed selection, feed use and disease control drugs use. Daily management measures are as follows:
A) Regularly monitor the aquaculture water quality, in which the source water quality is tested once every 10 day and the aquaculture pond water quality is tested once every 15 day. The standard NY505 1-200 1 is adopted, and the PH value is required to be 7-8.5, the transparency is about 30CM, and the dissolved oxygen is above 4 mg/L ... The water quality of the base has been sampled and tested by Guangdong Fisheries Quality Supervision and Inspection Center at the water inlet and pond, with 12 items, including color, smell, taste, total coliform and mercury. All of them meet the water quality of pollution-free food freshwater culture (NY5056544)
B) Production personnel shall keep records of aquaculture production, recording the species of aquaculture, the source and growth of fry, the source and feeding of feed, the change of water quality, etc. Make a scientific breeding plan to promote the healthy growth of breeding objects.
C) Correct use of fishery feed, feed additives and aquatic drugs. All crocodiles are fed to the fresh tilapia, silver carp and bighead carp cultured in this base, and they are fed in a reasonable and balanced manner according to the requirements of each growth stage of crocodiles. Observe the daily crocodile activities, water quality changes and weather conditions, flexibly determine the daily feeding amount, ensure that crocodiles eat well and do not waste, and prohibit the release of spoiled fish. Tilapia, silver carp and bighead carp in the base are prohibited from using "three noes" feed and feed additive products. Prevent feed deterioration and expiration; Don't use illegal drugs to prevent fish diseases. Disease prevention adopts the principle of "prevention first, combining prevention with treatment", focusing on biological agents and reducing the use of chemical drugs. The comprehensive measures to prevent fish diseases include: ① selecting self-bred or healthy disease-free crocodile seedlings imported from Thailand for stocking. ② Choose healthy and disease-free tilapia, silver carp, bighead carp and other fry for stocking. Disinfect and sterilize the fry before entering the pool; Choose high-quality feed; Regularly use biological agents such as photosynthetic bacteria and water quality improvers to regulate water quality.
At the same time, fresh water and circulating water are continuously injected into the crocodile pond to ensure the freshness of the pond water. At the same time, the old water in the crocodile pond is discharged into the fish pond where tilapia, silver carp and bighead carp are raised, and the aquaculture wastewater in the crocodile pond is fully utilized to ensure ecological balance and environmental sanitation.
D) pay attention to heat preservation. Crocodiles that overwinter are not cold-tolerant. When the water temperature drops to 15℃, they will stop moving. In winter, the weather is cold, so we cover the crocodile pond with film, and take out high-temperature water from the deep well and inject it into the pond to ensure the safety of crocodiles and other fish in winter. At the same time, crocodiles are more active and open their mouths to eat, so that they can grow and develop in winter.
Second, the result
After more than three years of cultivation, feed fish such as crocodiles (tilapia, silver carp and bighead carp) grow well, basically without diseases, with high yield, good quality and high economic benefits. At present, there are more than 20,000 crocodiles of various specifications in the whole base, and the commercial crocodiles harvested in 2004 reached more than 30 tons (1000, each weighing more than 30 kilograms). The meat is delicious, sweet and crisp, and exported to Beijing, Shanghai, Guangzhou, Dalian and other places, which is deeply loved by consumers. Crocodiles produced in this base have been inspected by Zhaoqing Animal Epidemic Prevention Supervision Institute of Guangdong Province, and the animal epidemic prevention conditions are qualified, which meets the food hygiene and safety standards and the international pollution-free food requirements. At the same time, crocodile meat is rich in high-quality protein and essential amino acids, unsaturated fatty acids, vitamins and various trace elements, such as protein 2 1.28%, calcium 46mg/kg, iron 5mg/kg, zinc 10 mg/kg, and vitamin A 532 ug/ 100.
Three. Discussion and analysis
In the course of more than three years' breeding, crocodiles grow well, grow faster than other farms, and have good quality and taste, mainly because we have one of the biggest and unique characteristics: crocodiles are fed with fresh feed fish (tilapia, silver carp and bighead carp) raised by ourselves to ensure the quality of feed fish; However, other crocodile farms at home and abroad buy feed fish from different places, and it is difficult to avoid problems with feed fish, which seriously affects the quality and taste of crocodiles. At the same time, we have four advantages: good farm land, good water quality environment, good seed quality and good daily management. Superior geographical environment, good water quality, healthy and disease-free seedlings, high-quality feed and strict management measures, the commercial crocodile developed is naturally a superior food with good quality and taste.
1. The breeding ground is very good. Crocodile breeding base is located in the mountain tourist area of Sihui Town, Guangdong Province. The environmental conditions in the whole region are excellent, and there is no industrial pollution, pesticide pollution and domestic pollution. Sufficient water, good water quality, fresh air and no pollution in soil. The base was recognized by Guangdong Ocean and Fisheries Bureau as a pollution-free agricultural product base in Guangdong Province.
2. The fresh water injected into the base has a good water quality environment, which is the spring water of Zhenshan Mountain. It is absolutely pollution-free and has fresh water quality, which fully meets the requirements of pollution-free and pollution-free breeding.
3. The quality of fry is good, and the choice of stocked fry must be healthy and disease-free.
4. In daily management, strictly implement water quality control management measures to prevent polluted water from entering. Correct use of feed and disease control drugs, all crocodiles are fed to the fresh tilapia, silver carp and bighead carp cultured in this base, and it is forbidden to put spoiled fish; Tilapia, silver carp and bighead carp in the base are prohibited from using "three noes" feed and feed additive products. Prevent feed deterioration and expiration; Don't use illegal drugs to prevent fish diseases.