Suitable technico-economic adjustments for poultry feeding in hot countries

Abstract

Two major factors limit the development of poultry productions in countries with hot climatic conditions : the climate reduces the energy intake of birds, requires adjustments in housing systems and slows down the production rate (delayed growth, smaller eggs...) while the importation of cereals and soybean paid with major currencies handicaps many of these countries. Suitable solutions for the nutrition of poultry must take into account these two kinds of constraints in the choice of data for formulating feed. The poultry sector must also be integrated within the general agro-industrial plans of development of the state. Seven examples of adjustements are given here as an illustration of collaborative research between INRA and various hot countries. To become effective, such examples need to be adapted by the professionals of the poultry sector to suit local conditions. Adjustements of feed composition using ad libitum feeding show a limited ability to compensate for the negative effects of heat on bird performance. However, some adjustments, such as increasing the amount of &dquo;poor quality&dquo; protein sources (i.e. with low essential amino acid yield) in the feed, may actually worthen the negative effects of a warm climate. Low energy pelleted diets are suitable for the low energy consuming laying hen of the tropic. This kind of feed could use large amounts of locally available by-products which have a nutritional value for birds, such as cereal by-products. A combined light and feed management program which prevents broilers from eating some hours before and during the daily heat peak leads to suppress the excessive mortality rate observed during the finishing period. The splitting of a complete diet into fractions opens new perspectives. Two of these diets already have shown interesting results :
- laying hens fed on a Separate Calcium Feeding program exhibit an increase of energy intake during the morning and improved egg production,
- whole cereal grains offered in free-choice situation, together with a complementary feed (and oyster shell for layers) allows the growing or adult bird to adjust its own diet. This technic may have economic implication by using locally available grain and would limit the losses linked to storage and transportation of feed, and concentrate the technical effort on a single complementary feed. Research for new feeding models which would include the existing rhythms of light and temperature inside open door poultry houses of tropical countries looks promising. It should stimulate scientific exchanges between Southern and Northern countries.