02816naa a2200469 a 450000100080000000500110000800800410001902400550006010000170011524501060013226000090023852014340024765000160168165000110169765000240170865000090173265000200174165000160176165000080177765000140178565000230179965300280182265300170185065300160186765300180188365300240190165300320192565300400195765300260199765300280202365300360205170000230208770000190211070000210212970000210215070000180217170000200218970000230220970000230223270000310225577300600228620596012017-03-30       2017    bl uuuu     u00u1 u    #d7 ahttp://dx.doi.org/10.1590/1678-992X-2015-02842DOI1 aBIASE, A. G.  aParametrization of the Davis Growth Model using data of crossbred zebu cattle.h[electronic resource]  c2017  aThe 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.  aBeef cattle  aCattle  aMathematical models  aZebu  aÁcido nucleico  aAgricultura  aDNA  aGado zebu  aModelo Matemático  aAsymptotic distribution  aCalibração  aCalibrating  aCattle growth  aCrescimento do gado  aDistribuição assintótica  aEquações diferenciais ordinárias  aModelo de crescimento  aNonparametric bootstrap  aOrdinary differential equations1 aDIAS, C. T. dos S.1 aBARIONI, L. G.1 aALBERTINI, T. Z.1 aMARTORANO, L. G.1 aOLTJEN, J. W.1 aLANNA, D. P. D.1 aOLIVEIRA, P. P. A.1 aMEDEIROS, S. R. de1 aTORRES JUNIOR, R. A. de A.  tScientia Agricolagv. 74, n. 1, p.8-17, Jan./Feb. 2017.