By Bisi Klah
Farming, fishing and hunting were the major traditional providers of food in Africa. Unlike hunting for other wildlife, the emphasis on snail is less, more remote or even absent. Like mushrooms, snails are picked in the wild mostly by women and children.
Influence of the principal external factors
A certain number of factors exert influence on snails and they are: (1) Temperature, which governs the activity of the snail. Very low or very high temperature leads to hibernation or estivation respectively. Snails require an average of 200C with a range of 70C to 280C. Humidity is when the snail is not in active life, except during the periods of rain or dew, whereas dryness (drought) induces its sleep (dormancy). Snails must constantly fight against dryness. Its preferential relative humidity is found between 75 and 95% (day 75%, night 95%). (2) Light: this has an influence on the behavior of the snail and on its activity. Light and photoperiodism have a great importance on the reproduction functions as well as on the growth. Photoperiod conditions are the maturation of gametes through the mechanisms which are tied to endocrine and neuro-endocrine factors. The photoperiod (per day) is about 16 to 18 hours for reproduction (long period); 16 hours for nursery growing (medium or long period); 12 to 18 hours favor the young; but combined flocks require 16 to 18 hours and light intensity is 7 to 10 watt/m2 of building space; (3) The last but most important factor is wind. When the wind is humid, snail does not withstand wind as this activates evaporation and dehydrates.
Each of these parameters (heating, humidification lighting, and isolation) affects the life of the snail directly. They are all to be taken into consideration. Neglecting one will mean compromising the success of the farm.
The simplest snail farming is based on collection from the wild (favored by the presence of forests and woody savannah). The snails are then placed in parks (runs), where they are fattened. Snail culture is not a perfect farming as there is still predation on the wild snails. It is essential to achieve all the biological cycle outside, by feeding the snails (planted vegetables in the parks, supplements and by controlling their predators). The divers’ natural phases (laying, incubation, hatching, growth…), occur normally within fenced areas. This technique is recommended in Italy. The combined method involving the reproduction (mating and laying) and the starting of the young in the nursery is carried out in confinements (of controlled temperature and humidity). The fattening, on the other hand, is done in open parks. This system allows for the acceleration of rotations and not to continually loot nature. Snailery infrastructure is a function of the available vegetation, space and funds. Moreover, if the farmer can participate meaningfully in the construction of the housing (in turn for his skills and time), the investment can still reduce. In tropical countries, rearing in open parks seems the most profitable method. (Integrated snail farm in crop rotation). Snail droppings are conserved to serve as manure for the crop to be planted afterwards.
Basic structures used for housing snails in the tropics
Tanks (pens) – wooden or concrete. Ideal dimension for ease of handling is 150 cm long x 40 cm deep. The tanks are placed under a roof and no wall. It is essential that snaileries are surrounded by a water trench (against soldier ants).
Baskets – local or plastic baskets of 60 cm diameter nested with substrate and covered with permeable/porous sheets. Baskets are placed on racks whose legs are rooted in small tins containing waste engine oil against termite and ant infestation.
Parks (Runs) – these are of small dimensions (4 – 10m2) of rectangular form. Side protections are of wire mesh size appropriate for a snail. The recommended dimensions are:Length = 3.5 – 6.5 m; Breadth = 1.2 – 1.5 m; Height of wire mesh protection = 0.40 – 0.50 m.
The feeders are placed under dwarf sheds (0.30m) against rain. Plantains serve as shade trees in the park. Depending on the type of structure, it is essential to have a substrate of 5 – 15 cm thick (based on the production objective and snail size).
Density (Floor space Allowance)
The recommended densities are as shown below: Breeders: 20 – 25/m2. Finishers: 50/m2.Growers: 100/m2. Starters: 150/m2. Feeding and Growth.
Snail is a phytophagous animal, which eats different green vegetables. The husbandry should be organized to greatly resort to local plants in the feed in a way to transform this plant biomass into animal protein. Snail has nocturnal feeding habits. They are active at night as well as during cloudy days or during morning rains to search for their food. It is possible that the African Snails enter into estivation if the ambient conditions become unfavorable notably by the reduction in the degree of the humidity of the air.