Cassava is one of the most important staple food crops grown in tropical Africa. It plays a major role in efforts to alleviate the African food crisis because of its efficient production of food energy, year-round availability, tolerance to extreme stress conditions, and suitability to present farming and food systems in Africa (Hahn and Keyser, 1985; Hahn et al., 1987). It can also play a major role in animal rations grain substitution in developing countries.  The objective of the research was to develop a suitable processing technology for the development of high quality cassava-based feed for snail which will enhance productivity, market value and profitability. 

The main materials used in the project work were cassava roots and cassava leaves (obtained from a private farm in Oshodi, Lagos State). Other feed ingredients used were maize, soybean meal (SBM), palm kernel cake (PKC), groundnut cake (GNC), oyster shell (OS), bone meal (BM), wheat offal (WO), brewer’s dry grain (BDG) and vitamin-mineral pre-mix (obtained from a reputable feed shop at Abattoir – Oko Oba, Agege, Lagos State). Aluminium sulphate and some soup ingredients used in the sensory evaluation of the snail meat were obtained from a local market.

Cassava roots were processed into meal using standard method of processing   involving peeling, grating, bagging and dewatering using a mechanical screw press (for 18 hours), and sun drying for 3 days(Gomez et al.,1987). Cassava leaves were processed into meal using the method of Ravindran et al., (1987). The leaves were chopped, washed, dried and milled by pounding.

Feeds (F1, F2 and F3) were formulated to contain 220, 235 and 245 g/Kg cassava root meal and 125, 105 and 85 g/Kg cassava leaf meal respectively.  The formulated feeds contain approximately 18.5% crude protein, 7.5% ash, 3% Fat, 8% calcium and energy level of 2400 Kcal ME / Kg. A total of 90 growing snails of spp. Archachatina marginata were used to investigate the nutritive potential of the formulated feeds. The performance of growing snails fed with the formulated feeds was investigated for 15 weeks. Organoleptic properties and economic of ingredient substitution were also determined. Feed Intake for snails fed with cassava-based feeds ranged from 573-584 g  as against 595 g for those fed with commercial poultry  feed (D4) while Weight Gain ranged from 88-96g (126-137%) as against 103g (146%) respectively. The performance parameters (feed conversion) show that D2>D3>D1 with snails performing better at CRM-CLM ranges of 23-25 % and 8-10 % respectively The dressing percent showed similar trend, improving from 39.76 (F1), 40.25 (F3) and 41.02 (F2).  There are significant higher mean scores (p<0.05) recorded by snails fed with the formulated feeds. Zero mortality was recorded in all the treatments. Comparatively, protein supplementation at above 31% was not economically justified and maize and wheat offal substitution is desirable at maximum levels of 24% and 8.5% respectively.

The worth of cassava and cassava leaves till today has been disdainfully undervalued. The profitability of livestock industries will largely depend on the appreciation of the true worth of these materials and their use. From the investigation so far, there exists a large potential for indigenous crops and their ‘wastes’ (in this case cassava roots and leaves) to substitute traditional and conventional feed grains in snail feed rations. Considering the feed intake, weight gain, feed efficiency ratio and dressing percent recorded cassava root and leaf meals can be successfully used as sources of carbohydrate (energy) and fibre respectively. From the comparison, the DM of the peels is high (up to 46% for cassava) and therefore, inclusion of these ‘wastes’ as source of fibre and part of diets for snail will  go a long way in reducing production cost while at the same time their disposal will no longer be a menace. However, protein supplementation must be done with utmost consideration for economic justification.