WATER RELATED PROBLEMS IN FISH FARMING.

Water parameters play a vital role in fish farming,these parameters are directly related to the stocking density ,feed and feeding technique.Oxygen levels in the pond must be maintained at 4mg/litre. The concentration can be altered when the weather changes such as excessive high temperature,this reduces the solubility of oxygen in the pond.This results in suffocation of the fish in the pond,this results in high mortality. The dissolved oxygen level is usually depleted in cases of heavy algae bloom,this results from excess use of manure in the pond.The amount of feed given at any point in time also imparts the level of oxygen.when there is overfeeding or just after feeding of the fish and there are excess feed in the pond because there is an increase in demand of oxygen to digest the feed.Overcrowding in the pond due to overstocking also depletes the oxygen concentration. The fish show signs when the water parameters are altered or when there is a compromise due to pathogenic agent.The fish crowd near the water surface gasping for air,they reject feed,they dont respond to noise and their sputum remains undissolved on water surface. The water in the pond should be changed and replaced with fresh water,stop feeding at this period and stop fertilization of the pond.The oxygen level is corrected by aerating the pond using air pumps/aerators to increase oxygen level. Ammonia level( 0.05mg/litre) is also another important health indicator.The feed components are the key factors,when feed content are not properly metabolized,they give off high levels of ammonia in waste material,leading to contamination of pond due to accumulation of waste at the bottom of the pond.The pond could also have high levels of ammonia,if there is a contamination of ponds by sewage waste due to a leak from sewage pipes. The fish responds by reducing feed intake and also come to the surface for air.The ammonia level can be corrected by using more easily metabolized feed ;this can be achieved by using atovi premix in fish feed.This ensures proper metabolism of feed without any ammonia buildup,thus maintaining the regular level of ammonia.The atovi premix acts on the feed,fish and water in the pond(read more about atovi and fish in previous posts).In ponds where atovi feed is not used,the pond level must be reduced,it must be flushed and clean water is added to oxygenate pond. Foul smelling /odor in the pond this is usually as a result of feeding uncooked offal's to the fish,this is a major cause of pollution in fish pond. The uncooked offal s usually crowd/clog the water surface,depleting oxygen concentration ,giving off foul odor with resultant death of fish. The effect is reversed by removing left over offal s on water surface,flush pond and fill pond with fresh clean water.The use of uncooked offal's should be stopped and use compounded ration instead. Fish health is hinged on good water parameters,feed quality,quantity and frequency of feeding,hence much attention must be given to these factors.Observation and good management protocol are the keys for a successful fish farming venture.

The role of water in fish farming.

Water is the natural habitat of fish thus for successful farming venture,the quality must be monitored and controlled.The growth of any fish depends on the water parameters,feeding protocol,feed composition and genetic potential of the fish specie. The sources of water for the fish farming could be any of the following; wells,dams,boreholes ,sea/lagoon and streams.The system of farming intended will dictate the source of water to be used.The earthen pond usually get water from streams,sea/lagoon and channeled springs while the concrete ponds are filled either from wells,boreholes or dams.The most important factor to consider is the quality of the water source. Water for fish farming must possess the following qualities; 1) The PH must be between 7-9,not acidic or too alkaline. 2)The water must be clean and free from contaminants/pollutants such as oil,chemicals,paints or heavy metals. 3)It must be odorless,free from scumb or foam. 4)It must contain enough dissolved oxygen 4mg/litre. 5)It must have a temperature of between 25-32 degree . 6) The carbon dioxide must not be less than 5mg/litre. 7)Ammonia level 0.05mg/litre. 8)Nitrate not less than 50mg/litre. 9)Nitrite not less than 0.30mg/litre. Water quality should be checked at regular intervals using a water kit and necessary adjustment made,a change in any of the water parameters leads to stress in the fish which could lead to severe loses. Oxygen a major index of water quality needs regular monitoring and balancing.The reduced and increased levels of oxygen has a bad effect on the fish.When oxygen level is depleted in the pond,it leads to suffocation and death of the fish,while supersaturation leads togas bubble disease in fish.The supersaturation usually occurs in algae bloom,where there is rapid photosynthesis resulting in small bubbles accumulating in fish intestines,muscles and gills causing the fish to float. The management practices also hamper on the health of the fish,so these must also be taken into consideration in fish farming.

FINGERLING PRODUCTION.

Fingerling production in cat fish farming is an essential part of the farm operation because it is the seed needed for production.The Clarias gariepinus spp is the common cat fish reared in Nigeria because of its early maturity taste,and the fact that it has an accessory breathing organ hence can survive outside water for some hrs,this explains why its sold live in the open markets. The mature male and female brood stock are chosen and kept in separate tubs,one male can fertilize 10 females.The males are bigger and heavier than the females,weighing over 1kg is the ideal .The males must have well developed genitals that are reddish indicating maturity. The females to be used must be identified as good spawners,with a weight of 450-500g,and must be over 8months with dark golden green eggs. The females are usually injected with hormones,the eggs expressed and mixed with milt of the male catfish.The male catfish is killed to extract the milt while the female is returned to pond after eggs are expressed. There are various hormones used in stimulating ovulation in fish such as ova prim, human chorionic gonadotropin, crushed pituitary gland and a combination of motilium and suprefact. The materials needed for the spawning include; a glass trough or a bath tub with water inlet and outlet pipes, screen with stand, pumps,bowls and net covering to keep tank covered and dark.The method you intend to use will dictate materials you will put in place. METHOD; The female brood fish to be used are injected with hormone,and left for 10 hours in a tank with flowing water,after which the eggs are stripped and placed in a bowl and fertilized with sperm from milt sac.The testis are cut in quarters,placed in a cloth and squeezed ,so that the sperm is caught on the bowl of eggs and the mixture is gently stirred.The fertilized eggs are placed on the screen in the bath tub and hatching occurs in 24-30 hours. The eggs can also be spawned in bowls with air pumps,this continuous movement of the water facilitates rapid hatching of the eggs .The eggs start hatching after 24 hours,you observe the hatchlings swimming in the bowl,allow 12 more hours for other eggs to hatch,after which you discard the unhatched eggs. The hatchlings are transferred to nursery tank,but are not fed until the 3rd day when there is complete absorption of yolksac. The fry's are fed with artemia ,and growth is observed and monitored.The fry's are sorted every week until they are a month old,then select the fingerlings for sale or continue rearing and sell as juveniles.

AURAL HAEMATOMA.

This refers to pocketing or ballooning of the pinna, with blood from damaged blood vessels in the ear. Aural haematoma can be caused by direct damage to vessels in the ear.

The damage could be as a result of bite wound,accidents,but the most common cause is severe head shaking and scratching which is associated with heavy tick infestation. Otitis media and allergic dermatitis are underlying causes of aural haematoma,hence thorough examination is essential in treatment protocol.

 Treatment of haematoma can be surgical or non surgical intervention.
 Haematomas can resolve on their own but the ear will assume a cauliflower shape,hence disfiguring the shape and size of ear.

 Non surgical intervention involves draining the fluid and flushing the cavity with saline to remove any clot or fibrin. The draining will be done a number of times because the haematoma recurs.There is a tendency for secondary bacteria infection because of several needle pokes,hence complicating the case of haematoma.

 The surgical intervention involves lancing the haematoma,flushing the cavity with saline,then some sutures are placed on the pinna.

The sutures are to hold the wall to the cartilage beneath,to ensure there is no space for pooling of blood.The incision site is not sutured,rather the sutures placed on both sides of pinna provide the necessary closure.

 The sutures are removed after a week, and the animal is placed on antilnflammtory drugs,analgesic and incision site is sprayed with wound oil treatment to repel flies.

The ear could be wrapped up in bandage or a head collar is placed on the animal to prevent cutting off the stitches.
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Vet and food safety

Tuberculosis a deadly zoonotic disease, and the rise in human cases has been linked to consumption of animal byproducts and flesh of animals with tuberculosis. This is one of the reasons why you must purchase your beef and animal by products from certified slaughter slabs and abattoir. The picture shows tubercles in lymph node,rib cage, and liver, The entire carcass was condemned and destroyed. Do not purchase beef that is tainted, smelly or discolored. Buy your animal products and byproducts from certified slabs and abattoir. Food safety and hygiene is our collective responsibility,do your part.

THE ROLE OF THE VETERINARIAN IN CURBING TUBERCULOSIS.

FISH HEALTH PROTOCOL.

The fish tank/pond is a summation of all activities carried out in the farm. The health status of the fish depends largely on management,this will determine the success of the venture.The prevention of fish diseases is achieved by implementing methods to prevent stress on the farm these include regular feeding with good quality feed,at specific feeding points at specific times. Fish should be given good quality feed at specific points at specified times to ensure proper observation this protocol ensures pond management as observation will dictate course of action. Predisposing conditions to fish diseases can easily be observed and prevented,these include poor water quality,overstocking and poor feed quality. The presence of dead fish or dying fish in the pond indicate a stress condition which can be attributed to pathogenic agents,bad feed,poor oxygen concentration e.t.c. HOW TO IDENTIFY SICK FISH; 1) the fish stops feeding. 2)the movement is sluggish,swimming by the side of tank. 3) skin discoloration. 4)lesion such as sores,pus ,white nodules on the skin. 5) fins rotten or frailed off. 6)gills are pale,hairy,white and covered with mucus. When you observe any of the above do the following; 1) isolate fish. 2)test the water parameter with a test kit. 3) check the fish thoroughly. 4)submit fish for laboratory diagnosis. 5)match the result with water analysis . 6) institute treatment based on result. The isolation of sick fish in treatment tank is to prevent spread/contamination of other stock,but ideally when you identify any sick fish you isolate them but ensure you drain the pond and replace with fresh water.This will ensure you flush out the causative agent and also alter the water parameter. It is very essential to treat all the fish in pond although those isolated will be treated separately and will only be returned to pond when health status is certified . Fish health management is a key to success of the venture, using Atovi feed premix is an advantage. It enhances the immune system of the fish keeping diseases away, the fish grows faster resulting in early harvest and fish are of big sizes fetching more profit. The premix ensures proper absorption of feed,so there is no wastage reducing the amount of feces hence pond is clean without undigested feed in pond. The use of atovi premix ensures a balance in water parameters as there are no nitrogenous deposits preventing nitrite toxicity which causes brown blood disease.It also prevents high ammonia deposit in pond because of complete metabolism of feed. FOR HIGHER FISH YIELD ;USE ATOVI PREMIX.