ESTIMATES OF GENETIC AND ENVIRONMENTAL PARAMETERS FOR REPEATED MEASURES OF MILK PRODUCTION IN GOATS

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Abstract

Abstract
The objective of this study was to compare mathematical functions in adjusting the mean and individual lactation curve of goats and to estimate genetic and environmental parameters for repeated measures of milk production. 183 lactations were used, 121 of Saanen goats and 62 of Alpine goats, of animals belonging to the Laboratory of goat and Sheep of UFPB/CCHSA. The milk control was performed at intervals of seven days. The adjustment was made to the mean curve using six mathematical functions: inverse polynomial, linear hyperbolic, incomplete gamma, quadratic logarithmic, linear and quadratic, and adjusted by interactive processes through non-linear regression. The criteria used to verify the fit quality for each function were adjusted coefficient of determination (R2a), percentages of deviation between observed and estimated total yields, percentages of typical curves, mean absolute deviation and mean square of residues. It was verified that any of the models tested can be used for mean curve estimates, but for the study of the individual curves, the incomplete gamma model should be preferred because it presents better estimates of the components of the lactation curve.
Keywords: dairy goats; lactation curve; mathematical models

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Author Biographies

George Rodrigo Beltrão da Cruz, Universidade Federal da Paraíba - Departamento de Ciência Animal

Engenheiro Agrônomo, Especialista em Caprinocultura e Ovinocultura, Mestre e Doutor em Zootecnia (Produção e Melhoramento Animal)

Daiane Gonçalves dos Santos, CCHSA/UFPB

Graduanda em Agroecologia CCHSA/UFPB

Edvaldo Mesquita Beltrão Filho, DGTA/CCHSA/UFPB

Engenheiro Agrônomo, Professor DGTA/CCHSA/UFPB.

Evandra da Silva Justino, CCHSA/UFPB

Técnica em Agropecuária, Licencianda em Ciências Agrárias CCHSA/UFPB

Aécio Melo de Lima, PPGTA/CCHSA/UFPB

Agroecólogo, Mestrando em Tecnologia Agroalimentar (PPGTA/CCHSA/UFPB).

Paulo Rodrigues Dantas Júnior, CCHSA/UFPB

Técnico em Agropecuária, Graduando em Agroecologia (CCHSA/UFPB)

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Published

2019-05-24

How to Cite

CRUZ, G. R. B. da; SANTOS, D. G. dos; BELTRÃO FILHO, E. M.; JUSTINO, E. da S.; LIMA, A. M. de; DANTAS JÚNIOR, P. R. ESTIMATES OF GENETIC AND ENVIRONMENTAL PARAMETERS FOR REPEATED MEASURES OF MILK PRODUCTION IN GOATS. Brazilian Animal Science/ Ciência Animal Brasileira, Goiânia, v. 20, p. 1–13, 2019. Disponível em: https://revistas.ufg.br/vet/article/view/47704. Acesso em: 17 jul. 2024.

Issue

Vol. 20 (2019): Continuous publication

Section

ZOOTECNIA

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