Data/hora: 05/06/2024 19:18:21

Provedor de dados: | 86
País: | Brazil
Título: | Adjustment of growth models in broiler chickens
Autores: | Demuner,Leandro Félix; Suckeveris,Diana; Muñoz,Julian Andrés; Caetano,Vinicius Camargo; Lima,Cesar Gonçalves de; Faria Filho,Daniel Emygdio de; Faria,Douglas Emygdio de.
Data: | 2017-12-01
Ano: | 2017
Palavras-chave: | Autocorrelated errors; Autoregressive model; Poultry science; Homogeneity of variance; Mathematical model; Weighting structures.
Resumo: | Abstract: The objective of this work was to investigate adjustments of the Gompertz, Logistic, von Bertalanffy, and Richards growth models, in male and female chickens of the Cobb 500, Ross 308, and Hubbard Flex lines. Initially, 1,800 chickens were randomly housed in 36 pens, with six replicates per lineage and sex, fed ad libitum with feed according to gender, and bred until 56 days of age. Average weekly body weight for each line and sex was used to estimate model parameters using the ordinary least squares, weighted by the inverse variance of the body weight and weighted with a first-order autocorrelated error structure. Weighted models and weighted autocorrelated error models showed different parameter values when compared with the unweighted models, modifying the inflection point of the curve and according to the adjusted coefficient of determination, and the standard deviation of the residue and Akaike information criteria exhibited optimal adjustments. Among the models studied, the Richards and the Gompertz models had the best adjustments in all situations, with more realistic parameter estimates. However, the weighted Richards model, with or without ponderation with the autoregressive first order model AR (1), exhibited the best adjustments in females and males, respectively.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017001201241

Editor:

Embrapa Secretaria de Pesquisa e Desenvolvimento

Pesquisa Agropecuária Brasileira

Relação: | 10.1590/s0100-204x2017001200013
Formato: | text/html
Fonte: | Pesquisa Agropecuária Brasileira  v.52 n.12 2017
Fonte: | info:eu-repo/semantics/openAccess