SNAIL FARMING By Adelaja A. Adesina B.Sc, M.Sc. (Ife); Ph.D. (Unilag in view)
Glorytime Animal Products Ltd Abudu Aina Estate, Opposite WAPCO Sagamu, Ogun State Tel:- 01 7624619, 08023187204; E-mail:-
[email protected]
Introduction The increasing population in Nigeria has led to increased demand for animal protein consumption, however, the supply of animal proteins from the traditional livestock like cattle, poultry, pigs, sheep and goat has been on the decline due to the many problems facing the livestock production industry. Efforts must therefore be intensified to improve the productivity of other less prominent animal protein sources to augment supply. The intensive production of mini-livestock like rabbits, quails, grass cutters, snails, etc., can bridge this widening gap between the demand and supply of animal proteins in the country. Snail rearing represents an important but hitherto neglected opportunity for a country like Nigeria to increase the availability meat for consumption, as snails could play significant roles in alleviating the problem of meat shortages prevalent in the country. The giant land snails have been an important component of food of numerous rural and urban dwellers in the country because the meat is highly palatable and very nutritious. Snail meat has been reported to be particularly rich in protein and iron and the protein content and amino acid profile compares favourably with those of beef, chicken, egg, pork and clarias fish. Snails are also reputed to have some medicinal value in treating hypertension and other circulatory system disorders. In traditional medicine, the bluish snail blood is used to treat whooping cough, asthma, among other ailments. The snail shell can also serve as raw materials for producing fertilizers, animal feeds, jewelry and other ornamental products. The shell can also be ground to powder and used for washing and scrubbing. However, of all these uses, it is the potential of snails as a good source of animal protein that has gained more recognition in Nigeria than other uses, the meat is well accepted in most parts of the country where it serves as a popular delicacy, especially in the rainy season of the year when snails are more abundant. Justification for Snail farming Over the years, the main source of supply of the giant land snail in Nigeria has been from the people who gather them from the wild and sell them off on roadsides and local markets. In the recent times however, the population of many of the animals in the wild including the giant land snails have declined considerably, primarily due to the impact of such human activities like de-forestation, bush
burning, the collection of immature snails and the use of chemicals in farming. As this trend continues, if there is no planned and sustained effort at replenishing, the snail may soon become one of the species of animals threatened with extinction. Apart from these, the harsh climatic conditions of the dry season also prevent the availability of snails on a continuous basis throughout the year, so at this period of the year, exorbitant prices are paid for snails. These reasons are why no effort should be spared in encouraging intensive snail rearing. The most widely distributed species of the giant land snail in Nigeria are i) Achatina
i)
ii) Archachatina
Achatina achatina this is the smaller of the two, it has a pointed apex and is more prolific, it can lay between 50 – 200 egg at once it is found mainly in some parts of the south western part of Nigeria
ii)
Archachatina marginata is far bigger than achatina, the shell is more bulbus, can be found in the entire rain forest belt of the southern parts of the country, there are two sub-species, these are a) A. marginata ovum, called the upland snails it has yellowish collumella, outer lip and apex, this is more common and is found in bushes and forests b) A. marginata suturalis, called the swamp snails it has reddish or pinkish collumella, outer lip and apex, this is less common, found mainly in the swampy and coastal areas of the country.
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
2
.
Present Status Past studies have established that the West African giant land snails Archachatina marginata and Achatina achatina can be reared in artificial environments similar to their natural environment, just like other livestock animals. Snail farming known as heliculture has been in practice by the Romans since the Paleolithic period, i.e. more than 2000 years ago From the early Romans initiative, snail farming has evolved tremendously and has reached advanced stages in Western Europe and Northern America where there are substantial numbers of commercial snail farms, producing snail (Helix species) for both the local and export markets. In Nigeria, the rearing of the giant land snails is just attracting increasing interests and this is a welcome development for the country. Snail farms of various shapes and sizes are now springing up all over the country, in Lagos area alone, apart from the numerous small-scale farmers; there are five well-established snail farms that have a population of snails ranging from more than 2000 – 10,000. A number of consultancy outfits have also been organizing seminars, workshops and training progammes in intensive snail production. STRATEGIES FOR INTENSIVE SNAIL PRODUCTION Housing The giant land snail love cool moist environment, as such the housing for snails must be made as close as possible to their natural habitat. A maximum temperature range of between 260C - 300C and relative humility of between 80 - 90% are considered ideal in snail houses. Other important features of snail houses are that they must be escape proof, keep predators away and allows for easy management of the snails. Housing types include
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
3
.
hutch boxes
trenches pens
mini paddocks
sand Crete/burnt bricks pens
tyre type
clay pots
Some of these housing types are presented in the figures below Fig 1a. Snail pen (exterior)
Fig 1b. Snail pen (interior)
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
4
.
Fig. 2 Sandcrete pens
Fig.3 Burnt bricks pens
Fig. 4 Trenches pens
Fig. 5 Another type of snail pen
It is necessary to create barriers in form of fence, gutters and rat guards around the snail housing to prevent predators and pests from accessing the snails easily. Stocking: Stocking with good foundation snails is very essential for successful snail production. Foundation stock could be obtained from already existing snail farms or from the open market. It is advisable to select young sexually mature snails with no cracks or wounds in any part of their body. On obtaining the foundation stock, they should be placed in the housing provided for them based on their sizes. A stocking density of 20 – 25 snails per 1m3 is recommended for whichever housing type is used. Care must be taken to avoid over crowding of the snails as over crowding will affect growth and reproduction of snails adversely. Feeding: For optimal growth and good reproduction, snails must be fed adequately with balanced diets that will enable them give their full potential. In their natural habitat, the giant land snails feed on tender parts of plants and decaying organic matter mainly of plant origin. Snails in captivity have been reported to thrive and multiply on a variety of diets that included leaves of common forages like paw-paw leaves and fruits, cabbage, coco yam leaves and peels, cassava leaves and peels and lettuce. They also feed well on fruits like paw-paw, mango, banana, oil palm, tomato and cucumber. However, most of these food items are in direct competition with man, therefore, there is a cost implication to feeding them to snails. Emphasis has now shifted to feeding snails on materials that are not in direct competition with
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
5
.
man, these include cassava leaves, okra leaves, centrocema tridax, aspilia africana, yam peels, banana peels, carrot leaves, maize duzza. Recently efforts are being made to feed snails on compounded feeds made from a mixture of common ingredients, just like other livestock animals, the belief is that this type of feeding apart from being cheaper on the long run will improve their growth rates and reproductive capabilities. However, the specific nutrients requirements of snails at various stages of their life cycle are not certain. Series of studies are ongoing to determine precisely the protein requirement, energy requirement, and mineral and vitamin requirements of snails at various stages of their life cycle In addition to the already identified feed stuff snails reared intensively will benefit from the supplementation of their diets with calcium sources like powdered oyster shell, bone meal or ground lime stone and egg shell; this will aid shell formation and production of strong egg shells. Further supplementation with vitamins and minerals should also be done to enhance productivity. For optimum performance, snails under intensive rearing systems should be fed adequately. The frequency of provision of feedstuff depends on the type of housing and rearing technique. For instance, snails reared in hutch boxes, trench pens, sand Crete pens, should be fed more frequently between 2 to 3 times a week whereas snails in mini paddocks or free range pens could be fed only once in a week as they can also supplement their feeding on their surrounding vegetation. As part of the feeding regime for snails, in intensive production system, water must be made available regularly both for drinking and for sprinkling to keep the snails cool, this will prevent aestivation and ensure continuous growth and reproduction. Reproduction Wild snails breed and reproduce freely in their natural habitat, reproduction is pronounced especially in the rainy season when the ambient temperatures are cool and humidity is high, whereas in the hot dry season, they remain inactive and sometimes aestivate until the weather becomes suitable for them to start mating and multiplying. Under intensive rearing conditions, the giant land snail can reproduce throughout the year when well fed and provided with adequate water.
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
6
.
The reproductive parameters of the two common species are shown in the table below; Table 1: Summary of Reproductive Performance
A. marginata
A. achatina
Adult Weight (g)
185 – 674
x = 380 + 22.9
100 – 180
x = 148 + 11.2
Age at Eggs laying
9 – 10 months
Clutch Size
4 –16
x = 7.9 + 0.7
50 – 200
x = 120
Weight of Eggs (g)
4.7 – 4.5
x = 3.2 + 0.2
2.0 – 2.6
x = 2.3
No. of Clutch/Year
6 –11
x = 7.7 + 0.21
5–8
x = 7.1
Hatchability of Eggs
70 – 75%
Incubation Period
21 – 35 days
6 – 7 months
65 – 70% x = 28.65 + 2.31
11 – 20 days x = 15.00 + 2. 11
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
7
.
The eggs should be packed with a plastic spoon as soon as they are laid into separate containers like wooden boxes, baskets or tins and covered with a thin layer of sand, and watered periodically for effective incubation. Healthcare Snails are also subject to diseases, parasites and pests, these include different types of worms, bacteria and fungi. Efforts to control some of these diseases and parasites in giant land snails are still at infancy. What we have now is a kind of extrapolatory treatment, where some drugs are administered to snails as a result of the action of such drugs in other animals; for instance, applying antibiotics on snails without determining the effect and side effects of such antibiotics on snails and man Maintenance of good sanitation through regular cleaning of snail houses will help reduce the incidence of diseases and parasites. Stievenart (1990) reported that introducing earthworms into snail pens could greatly reduce cleaning problems as the earthworm can recycle wastes from the snails. Also, by avoiding over crowding of snails in their pens/houses will help keep the snails in good health. Marketing. All the strategies listed above – housing, feeding, reproduction and healthcare are geared towards improving production, i.e. making more snails available. The strategies for intensive production of snails will not be complete without looking at how the snails will be sold. The demand for snails already exists among the Nigerian populace; this is talking about people who eat snails regularly as a delicacy. But in a situation where thousands of snails are going to be churned out on a regular basis under the intensive rearing system canvassed for here, there is need to develop the snail market beyond the already existing demand levels. Therefore, snails should be processed and packaged snails in such ways that they can easily be sold off by the farmers and the consumers too can easily utilize the meat without going through the rigors of breaking and cleaning the snails before they can eat them.
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
8
.
Snails can be processed for local markets and sold in super markets, stores, hotels and restaurants. They can also be processed and exported to Western Europe and Northern America. The forms of presentation can be as: -
Frozen snails
-
Oven dried snails
-
Fried snails
When the meat has been disposed as food, the snail shell can be utilized by the feed milling industry as a source of calcium in the animal feeds and can also be used in the ornamental cottage industry. Conclusion As the nation marches on in the quest sustainable food production, potentials of commercial snail production as a means of improving the supply of animal protein to the Nigerian populace is great. Efforts must be intensified to encourage large, medium and small scale production of snails, as this will not only alleviate the problem of low meat consumption. I want to believe that by your attendance of this particular workshop on snail rearing a seed has been sown in hearts; as such this effort has not been in vain. Therefore, irrespective of your profession or past experiences, put what you have heard here today into practice, start small and grow into the business. You, your family and friends will have snails to eat and depending on your scale of production, you can generate some supplementary income for yourself. I must however caution that snail farming is not a quick fix, fast money making business as it being erroneously touted in some quarters; it is a venture that must be carefully and patiently nurtured to give the desired returns.
THANK YOU
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
9
.
References Ajayi S.S, Tewe O.D., Moriaty C. And Awesu. (1978), Observation on the Biology and Nutritive Value of the African Giant Land Snail Archachatina marginata. East African Wildlife Journal 16: 85 –95 Awah .A.A. (1992) Snail Farming in Mature Rubber Plantation: Studies on Aspects of Specialized Production Techniques for Farming Archachatina
marginata. Snail
Farming I4:33 – 39. Cobbinah J.R. (1992). Snail Farming in West Africa – A practical guide. A Publication of Technical Centre for Agricultural and Rural Co-operation (CTA) 31p Egonmwan R.I. (1988). Reproductive Biology and Growth of the Land Snails, Archachatina marginata, ovum and Limicolaria flammea D.Phil. Thesis, Oxford University 186p Elmslie L. J. (1982). Snails and Snail Farming. World Animal Review 41: 20 – 26. Hodasi J.K.M. (1986). Some observation on the feeding behaviour and food preferences of the Giant West African snail Archachatina marginata Snail Farming Research 1 54 - 65 Hodasi J.K.M. (1989). The potential for Snail Farming in West Africa: Slugs and Snails in WorldAgriculture. 41 27 – 48 Imevbore E.A. (1990). Observations on the Response of African Giant Snail Archachatina Marginata to Varying moisture Conditions in Captivity. Snail Farming Research 3. 15 – 20 Plummer J. M. (1975). Observation on the Reproduction, Growth and Longevity of a Laboratory Colony of Archachatina (Calachatina) marginata (Swainson) Sub-species ovum. Proceeding of Malacological Society London. 41, 395 – 413
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
10
.
Stievenart C. (1990) Rearing of Giant African Snails on Soil Containing a Population of Earth Worms. Snail Farming Research 3: 12 –14.
Paper presented at the the workshop on entrepreneurship and skills acquisition organized by De Potter’s Vessels Society; St. Dominic’s Catholic Church, Yaba, Lagos. June 9th 2007
11
.
