Title:	Parametrization of the Davis Growth Model using data of crossbred Zebu cattle.
Authors:	BIASE, A. G. DIAS, C. T. dos S. BARIONI, L. G. ALBERTINI, T. Z. MARTORANO, L. G. OLTJEN, J. W. LANNA, D. P. D. OLIVEIRA, P. P. A. MEDEIROS, S. R. de TORRES JUNIOR, R. A. de A.
Affiliation:	Adriele Giaretta Biase, Universidade de São Paulo/ESALQ/DES; Carlos Tadeu dos Santos Dias, Universidade de São Paulo/ESALQ/DES; LUIS GUSTAVO BARIONI, CNPTIA; Tiago Zanett Albertini, Universidade de São Paulo/ESALQ/DAS; LUCIETA GUERREIRO MARTORANO, CPATU; James W. Oltjen; Dante Pazzanese Duarte Lanna, Universidade de São Paulo/ESALQ/DAS; PATRICIA PERONDI ANCHAO OLIVEIRA, CPPSE; SERGIO RAPOSO DE MEDEIROS, CNPGC; ROBERTO AUGUSTO DE A TORRES JUNIOR, CNPGC.
Date Issued:	2017
Citation:	Scientia Agricola, v. 74, n. 1, p. 8-17, January/February 2017.
Description:	The system of differential equations proposed by Oltjen et al. [1986, named Davis Growth Model (DGM)] to represent cattle growth has been parameterized with data from Bos taurus (British) and Bos indicus (Nellore) breeds. The DGM has been successfully used for simulation and decision support in the United States. However, the effect of about 30 years of genetic improvement and the use of different breeds may affect the model parameter values, which also may need to be re-estimated for crossbred animals. The aim of this study was to estimate parameter values and confidence intervals for the DGM with growth and body composition data from Zebu crossbred animals. Confidence intervals and asymptotic distribution were generated through nonparametric bootstrap with data from a field experiment conducted in Brazil. The parameters showed normal probability distribution for most scenarios. The rate constant for deoxyribonucleic acid (DNA) synthesis had a minimum increase of 156 % and the maximum of 389 %, compared to the original values and the maintenance requirement had a minimum increase of 126 % and maximum of 160 % compared to the original values. Lower limits of 95 % confidence intervals for the parameters related to maintenance and protein accretion rates were higher than the original estimates of the DGM, evidencing genetic differences of the Zebu crossbred animals in relation to the original DGM parameters.
Thesagro:	Gado zebu DNA Ácido nucleico
NAL Thesaurus:	Cattle Zebu
Keywords:	Cattle growth Nonparametric bootstrap Ordinary differential equations Asymptotic distribution Calibrating Calibração Crescimento do gado
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CNPGC)