There are several species of snail with varying nutrient profile. The protein content of snail meal (53-83%) is comparable to or higher than fish meal. Apart from lower methionine, the essential amino acids composition of snail protein is similar to fish meal and better than soybean meal. The fat of snail meal is high in polyunsaturated fatty acids and has a good supply of essential fatty acids (linoleic, linolenic and arachidonic acids) and minerals. These qualities make the meal a suitable substitute for more expensive, conventional protein feedstuffs. The variability in nutritional content, potential presence of anti-nutritional factors (cyanide, tannins and saponins) and the seasonal availability of snails (mainly during the moist season) are major factors limiting the use of snail meal in poultry diets on a commercial scale. However, heat processed snail meal could be effectively utilised for practical on-farm feed applications to reduce cost and provide an environmentally friendly method of controlling snails, especially where they are major agricultural pests. In suitable regions, snails could be intensively bred to ensure the availability of the meal in commercial quantities for poultry feeding. Heat processed snail meal is recommended at 10% in the diet of meat and egg-type chickens but raw snail meal is not. The composition of snail meal (nutritional and anti-nutritional properties), recommendations in diets for domestic chickens, results of some feeding experiments and major constraints to its efficient utilisation are discussed in the following paper.

Mango (Mangifera indica) is an important fruit crop grown in the tropics mostly for its pulp. Mango seed, which represents between 20-60% of the fruit, has limited food or industrial use in most producing countries and is therefore wasted. The kernel contained in the seed (mango seed kernel: MSK) is a good source of carbohydrates (58-80%), contains moderate quantities of proteins (6-13%) and fat (6-16%). The protein of MSK has a good essential amino acid profile and its oil is a good source of stearic and linoleic acids. However, despite these attributes MSK contains a number of anti-nutritional factors (e.g. tannins, phytate, cyanide, antitrypsin, oxalate and saponins) which limit its utilisation in poultry diets. Amongst these factors, tannins are largely responsible for the poor nutritional value of MSK. Several processing methods have been used to reduce the concentration of anti-nutritional factors in MSK and improve its utilisation by poultry. The following paper reviews the composition (nutrients and anti-nutrients) of MSK, recommendations for its use in poultry diets and processing methods to enhance its utilisation by poultry.

The authors review the main studies of the last 30 years concerning the chemical and nutritional features of sorghum grain. They describe the problems related to the tannins which lower to various extents its metabolizable energy value, palatability and protein utilization for chickens. They also emphasize that the new sorghum cultivars with low tannin content and nutritive value similar to maize really are suitable for use as the only cereal component of commercial poultry diets.