Values of Metabolizable Energy and Metabolization of Nutrients for Slow- and Fast-growing Birds at Different Ages

FR Santos,MB Café,PR Oliveira,CS Minafra,EF Duarte,JH Stringhini

doi:10.1590/1516-635x1704517-522

FR Santos, MB Café + Show 4 more

Open Access

https://doi.org/10.1590/1516-635x1704517-522

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Abstract

Two trials were performed to determine apparent metabolizable energy (AME) and AME corrected for zero nitrogen balance (AMEn) values and coefficients of apparent metabolizability of nitrogen (CAMN) and of ether extract (CAMEE) of slow- and fast-growing broilers (Isa label and Cobb, respectively) fed four different diets between 10 to 17 days or 28 to 35 days of age. The method of total excreta collection was applied. The tested feedstuffs were corn, whole corn germ (WCG), sorghum, and soybean meal (SBM). A randomized block experimental design was applied, with two treatments (breeds) and four replicates of ten animals each in the first trial, and four replicates of six animals each in the second trial. No differences in CAMN values were observed between the breeds; however, Isa Label birds presented higher CAMEE for all tested feedstuffs. The AME and AMEn values obtained in Isa Label chickens fed the corn diet were 5.75 and 3.44% higher relative tothe Cobb birds, respectively. Breed did not influence AME and AMEn values of the other tested feedstuffs. Independently of breed, age influenced the AME and AMEn values of WCG, sorghum and SBM, suggesting that birds become utilize feed more efficiently as they age.

Highlights

In order to formulate economically viable feeds, it is important to know the nutritional value of feedstuffs, which requires determining their chemical composition, nutrient availability, and energy content and utilization by a given species (Generoso et al, 2008)
The apparent metabolizable energy (AME) and AME corrected for zero nitrogen balance (AMEn) values obtained in Isa Label chickens fed the corn diet were 5.75 and 3.44% higher relative tothe Cobb birds, respectively
Additional studies are required to elucidate nutrient utilization of protein- and energy-rich feeds used in slow-growing broilers, because bird age, which is associated with the development of the gastrointestinal tract, may interfere with the nutritional evaluation of feeds, as mentioned by Calderano et al (2012)

Summary

INTRODUCTION

In order to formulate economically viable feeds, it is important to know the nutritional value of feedstuffs, which requires determining their chemical composition, nutrient availability, and energy content and utilization by a given species (Generoso et al, 2008). Considering that the growth rate of Isa Label chickens is slower than that of fast-growing broiler strains, their rates of digestive tract growth and enzyme production may be different from those of broilers selected to fast growth This difference in gastrointestinal development may influence nutrient utilization, which has implications for the Santos FR, Stringhini JH, Oliveira PR, Duarte EF, Minafra CS, Café MB formulation of feeds for slow-growing chickens, which feeds are commonly formulated based on nutritional data derived from fast-growing breeds. The current study was performed to determine the chemical composition, coefficients nutrient metabolization, and levels of apparent metabolizable energy and apparent metabolizable energy corrected for nitrogen of selected feedstuffs included in the diets of slow- and fast-growing broiler chickens at different ages

MATERIALS AND METHODS

Experimental Procedure and Chemical Analysis

RESULTS AND DISCUSSION