The methodologies applied to chickens and laying hens, to determine the digestibility and requirement of protein and amino acids are used with quails, however, they need a more careful evaluation due to peculiarities inherent to the Coturnix genus, in order to provide consistent results. The nutritional requirements of the birds are determinate using the dose-response and the factorial method. Several mathematical models and techniques of diet formulation are allied to the dose-response method in determining nutritional requirements. The curvilinear (hyperbolic) models better portray population behaviour in response to increasing nutrient doses in diets. The reading model, allow a better estimation of the requirement, in relation to the mathematical models used in the dose-response method. The techniques of comparative slaughter and nitrogen balance are effective in determining the nutritional requirements of quails, however, the latter need to be corrected by the loss of nitrogen in the feathers in determining the requirements of crude protein and amino acids for maintenance. The protein-free diet, coupled with the industrial amino acid supplementation, provides more robust digestibility values, since it more effectively predicts the endogenous excretion pattern.
Part of the book: Amino Acid
The Japanese quail (Coturnix coturnix japonica) rearing activity has grown considerably over the past few years. The purpose of this study was to compare diet formulations based on total (TAA) and digestible amino acids (DAA) and the use of different protein sources such as meat cum bone meal and feather meal in Japanese quails. The first three treatments were based on TAA, formulated based on corn and soybean meal (CST); meat and bone meal (CSMT); feather meal (CSMFT). The three other treatments received the same sequence of ingredients as the previous treatments; however, the diets were formulated based on digestible amino acids (DAA) (CSD, CSMD, and CSMFD). The results show that the base of diet formulation improves the performance of quails from 1-21d and the quails show that is possible to replacement of soybean meal with animal-origin by-products such as meat bone meal and feather meal, buts is needed to evaluate more aspects. In conclusion, diets formulated base on DAA for Japanese quails can be utilized with the same efficiency as diets based on TAA.
Part of the book: Advances in Poultry Nutrition Research