Fecha/hora: 05/06/2024 02:43:33

Biblioteca(s): | INIA Las Brujas.
Fecha corriente: | 21/02/2014
Fecha de la última actualización: | 04/02/2020
Autoria: | RAVAGNOLO, O.; MISZTAL, I.
Afiliación: | OLGA RAVAGNOLO GUMILA, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; I. MISZTAL, Dept. of Animal and Dairy Science, University of Georgia, Athens, GA, United States.
Título: | Studies on genetics of heat tolerance in dairy cattle with reduced weather information via cluster analysis.
Año de publicación: | 2002
Fuente/Imprenta: | Journal of Dairy Science, June 2002, Volume 85, Issue 6, Pages 1586-1589. OPEN ACCESS. DOI: https://doi.org/10.3168/jds.S0022-0302(02)74228-8
ISSN: | 0022-0302
DOI: | 10.3168/jds.S0022-0302(02)74228-8
Idioma: | Inglés
Notas: | Article history:

Contenido:

ABSTRACT.
The objective of this study was to explore the possibility of reducing the number of weather stations for studies on genetics of heat tolerance in dairy cattle. The similarity of information from 21 Georgia weather stations was analyzed by cluster analysis. Two major clusters have been found, separating Georgia along the NE and SW line. One weather station was selected for each of the clusters based on the minimal distance to all the remaining weather stations and on completeness of the weather information. The production dataset consisted of 114,751 first-parity test-day records for milk on 14,297 Holsteins from 120 herds in Georgia. Analyses using a model for daily milk yield with temperature-humidity index classes and several other fixed effects showed no increase in error sum of squares when using only two weather stations. The threshold of heat stress was different for each of the two regions but the rate of decline after the threshold was similar. After accounting for different thresholds, the genetic component of heat tolerance for milk was higher with the two-station model. Genetic studies on or evaluation for heat tolerance based on information from a few carefully selected weather stations can be as accurate as those based on information from numerous such stations.

Palabras-Clave: | Dairy; Heat stress; Random regressions.
Categoría del tema: | L01 Ganadería
URL: | https://www.journalofdairyscience.org/article/S0022-0302(02)74228-8/pdf
Registro original: | INIA Las Brujas (LB)
Ejemplares: | LB - (12856-1) - PXI - AP - DD - PP/JR.DAIRY SCIENCE/2004 -  -  - DIS