Variation in Quality of Maize Grain Due to Source, Moisture Content and Processing

Abstract

The aim of this project was to identify the major changes in the physiochemical composition of maize grain when subjected to different processes and response of broiler chickens on diets containing such grains. Source of grain, stage of harvest, milling technique, particle size, dietary inclusion level, and supplementation with microbial enzymes were investigated, in terms of grain physicochemical quality and nutritive value to broiler chickens. Feeding trials were conducted on male Cobb broiler chicks from day-old through to 21-day of age in each instance. All feed was provided as mash and experiments were conducted in environmentally controlled housing. Each experimental chapter has been presented as a stand-alone research paper. ... To sum up, it is clear that there is a significant variation in the quality of maize grain and many other factors are responsible for these differences. The source of maize and the milling technique do not have much influence on its nutritive quality. It is obvious that maize grain can be used at a much higher level than is currently the case in the industry. Maize quality, in particular starch quality, is reduced by heat treatment, especially of high-moisture grains. Such maize should be dried artificially at less than 100°C and its nutritive value sustained by adding an appropriate enzyme cocktail to the diets. There is a need for future research into processing and use of high-moisture maize grains, especially when held in long-term storage after drying. A wider range of microbial enzymes should be tested on such maize and the effects of diets with this kind of grain on mucosal morphometry and digestive function of birds should be assessed.