Summary

The generation of data, including digestion rates of feed ingredients, is required to enable practical nutritionists to adopt digestive dynamics for formulating broiler diets. Our research has established that feed conversion efficiency is influenced by the bilateral bioavailability of protein and starch and it may be enhanced by the dietary balance of rapidly digestible protein and slowly digestible starch. Digestive dynamics gives recognition to the extents, sites and rates of protein and starch digestion. Static digestibility coefficients do not account for the different absorption rates which vary across different feedstuffs; the kinetics associated with differences in relative absorption rates of nutrients is necessary for a better understanding of the value of feedstuffs. Innovative in vitro approaches evaluating the quality of feedstuffs including Promatest protein solubility, RVA starch pasting properties and Symes particle size index should prove indicative of protein and starch digestive dynamics. Therefore, the objectives are:
(i) to explore the employment of in vitro assessments to predict digestive dynamics in feedstuffs
(ii) to determine in vivo protein and starch digestive dynamics in standard cereal grains and protein meals per se and the relativity of in vitro and in vivo data
(iii) to establish algorithms to formulate broiler diets based on protein and starch digestive dynamics. Ultimately, formulation of diets for broiler chickens based on digestive dynamics will enhance their growth performance and nutrient utilisation in comparison to conventional approaches.

Program

Chicken Meat

Research Organisation

The University of Sydney

Objective Summary

The primary objective of this project is to formulate diets for chicken-meat production based on protein and starch digestive dynamics on the basis of coupled in vitro and in vivo data for relevant feedstuffs. As a consequence, nutritionists will be better positioned to predict and improve the efficiency of feed conversion and nutrient utilisation in broiler chickens. An underlying objective is to relate in vitro assessments, especially Promatest protein solubilities and RVA starch pasting profiles amongst others, to poultry performance in general and specifically to protein and starch digestive dynamics. Validated in vitro methodologies should provide the basis for an improved, modern approach to formulating broiler diets.