Nonlinear models for fitting growth curves of Nellore cows reared in the Amazon Biome

Marinho, Kedma Nayra da Silva; Freitas, A. R. de; Falcão, Alencariano José da Silva; Dias, Francisca Elda Ferreira

doi:10.1590/s1516-35982013000900006

Cited by 26 publications

(27 citation statements)

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“…Esse critério está relacionado à facilidade computacional de análise dos dados; o maior número de iterações necessárias para a convergência no modelo BD indicou maior dificuldade computacional de ajuste desse modelo aos dados, contudo, sOuzA et al (2010) e MArinhO et al (2013) relataram maior facilidade de convergência dos parâmetros utilizando o modelo BD em comparação aos demais modelos estudados.…”

Section: Resultsunclassified

“…Esse critério indica a associação entre os valores observados e os estimados, ou seja, quanto menor o quadrado médio do erro, melhor é a associação (MArinhO et al, 2013). Resultado contrário foi relatado por TeDesChi et al (2000), em que o quadrado médio do erro dos modelos VB, LG e GP diferiram dos valores encontrados para a função BD.…”

Section: Resultsunclassified

“…Na literatura observam-se valores acima de 0,76 (OLiVeirA et al, 2000;FreiTAs, 2005;GArnerO et al, 2005;sAnTOrO et al, 2005;hirOOkA, 2010;GOnçALVes et al, 2011;MArinhO et al, 2013). Considerando que o conjunto de dados do presente estudo é composto por animais de diferentes composições genéticas e, portanto, apresenta grande variabilidade, o valor de R a ² acima de 0,74 demonstra ajuste dos modelos aos dados.…”

Section: Resultsunclassified

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Comparação de modelos não lineares para descrever o crescimento de fêmeas leiteiras mêstiças taurino x zebu no Nordeste do Brasil

et al. 2016

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*Autor correspondente: mika@usp.br RESUMO: Objetivou-se comparar as funções matemáticas de Brody (BD), Von Bertalanffy (VB), Logístico (LG) e Gompertz (GP), identificar a que melhor descreve o crescimento, estimar componentes da curva (peso assintótico: a; índice de maturidade: k) e caracterizar o formato (ponto de inflexão: PI; taxa de crescimento instantâneo: TCI) da curva média de crescimento de fêmeas mestiças (Bos taurus x Bos indicus) em sistema de produção semi-extensivo. Foram utilizados 537 registros de pesagens realizadas em intervalos de 30 dias durante o período de 2010 a 2012, pertencentes a três propriedades. Os valores de a e k foram, respectivamente, 1.982 kg e 0,000286 kg/dia para BD; 550,50 kg e 0,00232 kg/dia para VB; 405,20 kg e 0,006374 kg/dia para LG e 479,70 kg e 0,00353 kg/ dia para GP. Baseado nos critérios estatísticos observou-se que os modelos VB, BD e LG apresentaram os maiores (>0,74) coeficientes de determinação ajustados (R a ²), e menor valor do resíduo foi encontrado no modelo GP (4.918,38), indicando que todos os modelos se adequaram estatisticamente aos dados observados. Para os critérios de interpretação biológica, os modelos VB (8,48 meses) e LG (9,4 meses) apresentaram PI mais próximos do observado, o modelo VB (12,04-0,535 kg/mês) foi o único capaz de descrever a TCI, e os demais modelos subestimaram o incremento de peso corporal. O modelo de VB apresentou o melhor ajuste aos dados de crescimento de fêmeas mestiças com alta variabilidade genética em sistema semi-extensivo.Palavras-chave: curva de crescimento, funções matemáticas, taxa de crescimento instantânea. COMPARISON OF NONLINEAR MODELS TO DESCRIBE THE GROWTH OF CROSSBRED TAURINE X ZEBU DAIRY COWS IN NORTHEASTERN BRAZILABSTRACT: The objectives of this study were to compare different mathematical functions [Brody (BD), Von Bertalanffy (VB), logistic (LG) and Gompertz (GP)], to identify the model that best describes growth, to estimate curve components (asymptotic weight: a; maturation rate: k), and to characterize the shape (point of inflection: PI; instantaneous growth rate: IGR) of the average growth curve of crossbred cows (Bos taurus x Bos indicus) raised in a semi-extensive production system. This study used 537 weight records from three farms obtained at intervals of 30 days over the period from 2010 to 2012. The values of a and k were, respectively, 1,982 kg and 0.000286 kg/day for BD; 550.50 kg and 0.00232 kg/day for VB; 405.20 kg and 0.006374 kg/day for LG, and 479.70 kg and 0.00353 kg/day for GP. According to the statistical criteria, models VB, BD and LG exhibited the highest (>0.74) adjusted coefficient of determination (Ra²), while the lowest residual value was observed for GP (4,918.38), indicating that all models accurately fit the data observed. Regarding the criteria of biological interpretation, models VB (8.48 months) and LG (9.4 months) provided a PI close to the observed, VB (12.04-0.535 kg/month) was the only model able to describe IGR, and the remaining models underestimated the increase in body...

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Section: Resultsunclassified

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Comparação de modelos não lineares para descrever o crescimento de fêmeas leiteiras mêstiças taurino x zebu no Nordeste do Brasil

et al. 2016

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“…Malaklar doğumu takip eden ilk 24 saat içerisinde tartılarak doğum ağırlıkları kayıt edilmiştir. Erkek ve dişi malaklar 360 günlük yaşa kadar, en az dört defa tartılmıştır [6,25] . Ağırlık ölçümleri 100 g hassasiyette ölçüm yapan 1000 kg kapasiteli baskül ile yapılmıştır.…”

Section: Materyalunclassified

Anadolu Mandası Malaklarında Büyüme Eğrisinin Çeşitli Doğrusal Olmayan Modeller Kullanılarak Karşılaştırılması

Şahin¹,

Ulutaş²,

Karadavut³

et al. 2014

Kafkas Univ Vet Fak Derg

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Bu araştırmada, doğrusal olmayan modeller ile Anadolu mandalarının canlı ağırlıklarındaki değişimi açıklamak için en iyi matematiksel modelin belirlenmesi amaçlanmıştır. Bu hedefle, Tokat ili ve ilçelerinde [2011][2012] Comparison of Growth Curve Using Some Nonlinear Models in Anatolian Buffaloe Calves SummaryThe aim of the research was to detect the best model to explain the variation of live weight of Anatolian buffaloes using the nonlinear models. For this purpose, in the production period of 2011-2012, live weight records of 640 heads Anatolian buffalo calves including 309 male and 331 female reared in different farm conditions of Tokat were used. To achieve the objective of the study, the non-linear models of Logistic, Richards, Gompertz and Brody function were used. To decide which one is the best model, the coefficient of determination (R 2 ) and the mean square error (MSE) statistics were used. The coefficient of determination (R 2 ) for Logistic, Brody, Gompertz and Richards models were found as 0.96, 0.92, 0.96 and 0.98 for female calves and 0.94, 0.93, 0.95 and 0.97 for male calves, respectively. And mean squared errors (MSE) were found as 682.32, 703.51, 548.66 and 498.63 for females and 637.48, 688.32, 598.12 and 528.74 for male Anatolian buffaloes, respectively. As a result, the best fitted model based on MSE and R 2 criterias was Richards model. Also, the growth and development traits such as sexual maturity age, breeding age, appropriate slaughter age in male and female Anatolian buffalo calves can be estimated using the Richards model. Keywords: Growth curves, Logistic

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“…Non-linear growth functions (e.g., Bhowmick & Bhattacharya, Gompertz, Logistic, Von Bertalanffy, Weibull and Richards), with parameters estimated by regression, describe animal growth (Bhowmick and Bhattacharya, 2014;Chizzotti et al, 2008;Forni et al, 2009;Freetly et al, 2011;Marinho et al, 2013;Nesetrilová, 2005). However, they have limited capacity to estimate body composition (i.e., fat and protein), thus, neglecting the possible interactions between metabolism and composition of gain dynamics (NRC, 1996).…”

Section: Introductionmentioning

confidence: 99%

Parametrization of the Davis Growth Model using data of crossbred Zebu cattle

Biase

Dias

Barioni

et al. 2017

Sci. agric. (Piracicaba, Braz.)

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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.

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Nonlinear models for fitting growth curves of Nellore cows reared in the Amazon Biome

Cited by 26 publications

References 15 publications

Comparação de modelos não lineares para descrever o crescimento de fêmeas leiteiras mêstiças taurino x zebu no Nordeste do Brasil

Comparação de modelos não lineares para descrever o crescimento de fêmeas leiteiras mêstiças taurino x zebu no Nordeste do Brasil

Anadolu Mandası Malaklarında Büyüme Eğrisinin Çeşitli Doğrusal Olmayan Modeller Kullanılarak Karşılaştırılması

Parametrization of the Davis Growth Model using data of crossbred Zebu cattle

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