Mixed-effects growth curves in the valuation of Nellore sires

Giolo, Suely Ruiz; Henderson, Robin; Demétrio, Clarice Garcia Borges

doi:10.1590/s0103-90162009000100012

Cited by 3 publications

(2 citation statements)

References 19 publications

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“…However, in a global sense, it was Brody's equation that held the closest approximation and that more adequately predicted the weight at birth. Giolo et al (2009) found that the Logistic curve provided a close approximation for this same breed. When comparing the same five biological models in the Guzerá breed, Oliveira et al (2000) found that although the Brody, Gompertz and Logistic models provided accurate estimations for the growth parameters, it was the Bertalanffy model that best estimated and predicted the growth of these animals raised under tropical conditions.…”

Section: Discussionmentioning

confidence: 79%

Growth modeling of castrated Brahman males raised in tropical conditions and born in different seasons

et al. 2012

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In this paper, parameters that describe growth, as a function of the season in which they were born (dry or rainy), are presented for males of the for males of the Brahman breed that were castrated at birth and raised in their native environment in the intense system of the Llano Venezolano. Data are presented for 1,478 Brahman males that were castrated at birth. Of these, 750 were born in the months of June and July (the rainy season) and 728 were born in January and February (the dry season). The animals born during the dry season were heavier up until the beginning of the fattening period; after weaning, the greatest average daily weight gain coincided in both groups during rainy periods when the pasture production was greater. When comparing the observed weights with the estimates, the Brody model was better at estimating the actual weight of the animals at birth, weaning and maturity in both seasons of birth. The Gompertz, Bertalanffy, Richards and Logistic models overestimated the weights of the animals at birth and at the end of the fattening period; however, they underestimated the weights at weaning and maturity for both birth seasons. Regarding the birth season, no differences were found in the estimated maturation rate for any of the models, although there were differences among the models for the same season of birth.

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Section: Discussionmentioning

confidence: 79%

Growth modeling of castrated Brahman males raised in tropical conditions and born in different seasons

et al. 2012

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“…The same as those discussed in traditional longitudinal models in this approach, the random effects are used for estimating inter-individual variability in intra-individual pattern Curran et al (2010). A normal distributional assumption is often used for both inter-individual errors and the random effects (See Giolo et al (2009), Chirwa et al (2014) and Ghisletta et al (2015)).…”

Section: Introductionmentioning

confidence: 99%

A Bayesian sensitivity analysis of the effect of different random effects distributions on growth curve models

Ganjali¹,

Baghfalaki²,

Fagbamigbe³

2020

JAS

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Growth curve data consist of repeated measurements of a continuous growth process of human, animal, plant, microbial or bacterial genetic data over time in a population of individuals. A classical approach for analysing such data is the use of non-linear mixed effects models under normality assumption for the responses. But, sometimes the underlying population that the sample is extracted from is an abnormal population or includes some homogeneous sub-samples. So, detection of original properties of the population is an important scientific question of interest. In this paper, a sensitivity analysis of using different parametric and non-parametric distributions for the random effects on the results of applying non-linear mixed models is proposed for emphasizing the possible heterogeneity in the population. A Bayesian MCMC procedure is developed for parameter estimation and inference is performed via a hierarchical Bayesian framework. The methodology is illustrated using a real data set on study of influence of menarche on changes in body fat accretion.

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Estimación de parámetros de curvas de crecimiento de ganado Nellore criado en confinamiento

O¹,

N²,

Rodríguez³

et al. 2011

Rev MVZ Córdoba

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RESUMENObjetivo. Comparar los modelos de regresión no lineal Brody, Gompertz, Logístico y von Bertalanffy, e identificar cual de ellos describe mejor el crecimiento de machos enteros Nellore criados en régimen de confinamiento, recibiendo suplementación alimenticia y sometidos a manejo experimental. Materiales y métodos. La estimativa de los parámetros de cada modelo se realizó a través del procedimiento para modelos no lineales PROC NLIN de SAS, a partir de datos de peso colectados desde los 352 hasta los 833 días de edad. Resultados. El cuadrado medio del error, el coeficiente de determinación y la dócima de Durbin-Watson permitieron concluir que todas las funciones presentaron comportamiento similar en su capacidad de ajuste; no obstante, el análisis de normalidad de residuos demostró que el modelo logístico no cumplió con este supuesto (p<0.05), limitando su habilidad predictiva bajo las actuales condiciones experimentales. Conclusiones. La condición de normalidad en los residuos de los modelos de Brody, Gompertz y von Bertalanffy (p>0.05) permitió asegurar que la inferencia sobre los parámetros fue adecuada, con independencia de los cambios de peso resultantes de la aplicación de diversos planos alimenticios. Por la interpretación biológica de los parámetros, el modelo Brody fue el que presentó la mejor descripción del crecimiento de machos Nellore. Los mayores pesos maduros y las menores tasas de madurez obtenidas en este trabajo, en relación con los reportes de la literatura, indica que los animales alcanzarían peso asintótico en edad más avanzada en razón de su desarrollo más lento, consecuencia del manejo experimental al que fueron sometidos.Palabras clave: Biomodelación, bondad de ajuste, masa corporal, regresión no lineal (Fuente: CAB).

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Mixed-effects growth curves in the valuation of Nellore sires

Cited by 3 publications

References 19 publications

Growth modeling of castrated Brahman males raised in tropical conditions and born in different seasons

Growth modeling of castrated Brahman males raised in tropical conditions and born in different seasons

A Bayesian sensitivity analysis of the effect of different random effects distributions on growth curve models

Estimación de parámetros de curvas de crecimiento de ganado Nellore criado en confinamiento

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