Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models.

MELO, C. M. R. de; PACKER, I. U.; COSTA, C. N.; MACHADO, P. F.; C. M. R. de Melo, UFSC; I. U. Packer, ESALQ/USP; Cláudio Nápolis Costa, Embrapa Gado de Leite; P. F. Machado, ESALQ/USP.

Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models.

Covariance components for test day milk yield using 263 390 first lactation records of 32 448 Holstein cows were estimated using random regression animal models by restricted maximum likelihood. Three functions were used to adjust the lactation curve: the five-parameter logarithmic Ali and Schaeffer function (AS), the three-parameter exponential Wilmink function in its standard form (W) and in a modified form (W*), by reducing the range of covariate, and the combination of Legendre polynomial and W (LEG+W). Heterogeneous residual variance (RV) for different classes (4 and 29) of days in milk was considered in adjusting the functions. Estimates of RV were quite similar, rating from 4.15 to 5.29 kg2. Heritability estimates for AS (0.29 to 0.42), LEG+W (0.28 to 0.42) and W* (0.33 to 0.40) were similar, but heritability estimates used W (0.25 to 0.65) were highest than those estimated by the other functions, particularly at the end of lactation. Genetic correlations between milk yield on consecutive test days were close to unity, but decreased as the interval between test days increased. The AS function with homogeneous RV model had the best fit among those evaluated.

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Bibliographic Details
Main Authors:	MELO, C. M. R. de, PACKER, I. U., COSTA, C. N., MACHADO, P. F.
Other Authors:	C. M. R. de Melo, UFSC; I. U. Packer, ESALQ/USP; Cláudio Nápolis Costa, Embrapa Gado de Leite; P. F. Machado, ESALQ/USP.
Format:	Artigo de periódico biblioteca
Language:	Ingles English
Published:	2007-10-17
Subjects:	Genetic parameters, random regression model, test day model, variance components, milk yield,
Online Access:	http://www.alice.cnptia.embrapa.br/alice/handle/doc/596115 https://doi.org/10.1017/S1751731107685036
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spelling	dig-alice-doc-5961152024-02-16T20:32:34Z Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models. MELO, C. M. R. de PACKER, I. U. COSTA, C. N. MACHADO, P. F. C. M. R. de Melo, UFSC; I. U. Packer, ESALQ/USP; Cláudio Nápolis Costa, Embrapa Gado de Leite; P. F. Machado, ESALQ/USP. Genetic parameters random regression model test day model variance components milk yield Covariance components for test day milk yield using 263 390 first lactation records of 32 448 Holstein cows were estimated using random regression animal models by restricted maximum likelihood. Three functions were used to adjust the lactation curve: the five-parameter logarithmic Ali and Schaeffer function (AS), the three-parameter exponential Wilmink function in its standard form (W) and in a modified form (W), by reducing the range of covariate, and the combination of Legendre polynomial and W (LEG+W). Heterogeneous residual variance (RV) for different classes (4 and 29) of days in milk was considered in adjusting the functions. Estimates of RV were quite similar, rating from 4.15 to 5.29 kg2. Heritability estimates for AS (0.29 to 0.42), LEG+W (0.28 to 0.42) and W (0.33 to 0.40) were similar, but heritability estimates used W (0.25 to 0.65) were highest than those estimated by the other functions, particularly at the end of lactation. Genetic correlations between milk yield on consecutive test days were close to unity, but decreased as the interval between test days increased. The AS function with homogeneous RV model had the best fit among those evaluated. 2024-02-16T20:32:34Z 2024-02-16T20:32:34Z 2007-10-17 2007 Artigo de periódico Animal. The International Journal of Animal Biosciences, Cambridge, v. 1, n. 3, p. 325-334, 2007. http://www.alice.cnptia.embrapa.br/alice/handle/doc/596115 https://doi.org/10.1017/S1751731107685036 Ingles en openAccess
institution	EMBRAPA
collection	DSpace
country	Brasil
countrycode	BR
component	Bibliográfico
access	En linea
databasecode	dig-alice
tag	biblioteca
region	America del Sur
libraryname	Sistema de bibliotecas de EMBRAPA
language	Ingles English
topic	Genetic parameters random regression model test day model variance components milk yield Genetic parameters random regression model test day model variance components milk yield
spellingShingle	Genetic parameters random regression model test day model variance components milk yield Genetic parameters random regression model test day model variance components milk yield MELO, C. M. R. de PACKER, I. U. COSTA, C. N. MACHADO, P. F. Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models.
description	Covariance components for test day milk yield using 263 390 first lactation records of 32 448 Holstein cows were estimated using random regression animal models by restricted maximum likelihood. Three functions were used to adjust the lactation curve: the five-parameter logarithmic Ali and Schaeffer function (AS), the three-parameter exponential Wilmink function in its standard form (W) and in a modified form (W), by reducing the range of covariate, and the combination of Legendre polynomial and W (LEG+W). Heterogeneous residual variance (RV) for different classes (4 and 29) of days in milk was considered in adjusting the functions. Estimates of RV were quite similar, rating from 4.15 to 5.29 kg2. Heritability estimates for AS (0.29 to 0.42), LEG+W (0.28 to 0.42) and W (0.33 to 0.40) were similar, but heritability estimates used W (0.25 to 0.65) were highest than those estimated by the other functions, particularly at the end of lactation. Genetic correlations between milk yield on consecutive test days were close to unity, but decreased as the interval between test days increased. The AS function with homogeneous RV model had the best fit among those evaluated.
author2	C. M. R. de Melo, UFSC; I. U. Packer, ESALQ/USP; Cláudio Nápolis Costa, Embrapa Gado de Leite; P. F. Machado, ESALQ/USP.
author_facet	C. M. R. de Melo, UFSC; I. U. Packer, ESALQ/USP; Cláudio Nápolis Costa, Embrapa Gado de Leite; P. F. Machado, ESALQ/USP. MELO, C. M. R. de PACKER, I. U. COSTA, C. N. MACHADO, P. F.
format	Artigo de periódico
topic_facet	Genetic parameters random regression model test day model variance components milk yield
author	MELO, C. M. R. de PACKER, I. U. COSTA, C. N. MACHADO, P. F.
author_sort	MELO, C. M. R. de
title	Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models.
title_short	Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models.
title_full	Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models.
title_fullStr	Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models.
title_full_unstemmed	Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models.
title_sort	genetic parameters for test day milk yields of first lactation holstein cows by random regression models.
publishDate	2007-10-17
url	http://www.alice.cnptia.embrapa.br/alice/handle/doc/596115 https://doi.org/10.1017/S1751731107685036
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Genetic parameters for test day milk yields of first lactation Holstein cows by random regression models.

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