Equações de predição para valores de proteína e energia digestíveis em alimentos de origem animal para tilápias

Abstract

The objective of this study was to formulate mathematical models to estimate values of digestible protein and energy of feeds for tilapias. Papers containing data on chemical composition of crude protein, ether extract and mineral matter, in addition to values of digestible protein and energy obtained in biological assays were used. The data were subjected to multiple linear regression, stepwise backward. Additionally, a digestibility trial with juvenile Nile tilapias of the GIFT strain was conducted to test five meat and bone meals to validate the obtained models and elaborate individual models for the ingredients. Values of digestible protein and energy of meat and bone meals were obtained using Guelph system to feces collection and chromium (III) oxide was used as indicator. It was not possible to obtain a reliable model to estimate digestible energy (DE) values of the ingredients. It was concluded that the model to estimate digestible protein values (DP) of animal origin is: PD (%) = 0.970 x CP - 0.290 x MM; R2 = 0.998. The models to estimate the digestible protein and energy values of the meat and bone meal were: DP (%) = 3.460 x EE - 0.347 x MM; R2 = 0.998 and DE (kcal/kg) = 6700.119 - 101.368 x MM; R2 = 0.965, respectively.