Fecha/hora: 05/06/2024 00:39:45

Biblioteca(s): | INIA Las Brujas.
Fecha corriente: | 21/02/2014
Fecha de la última actualización: | 03/10/2019
Autoria: | RAVAGNOLO, O.; MISZTAL, I.
Afiliación: | OLGA RAVAGNOLO GUMILA, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; I. MISZTAL, University of Georgia, United States.
Título: | Effect of heat stress on nonreturn rate in holstein cows: Genetic analyses.
Año de publicación: | 2002
Fuente/Imprenta: | Journal of Dairy Science, 2002, 85 (11): 3092-3100.
ISSN: | 0022-0302
DOI: | 10.3168/jds.S0022-0302(02)74396-8
Idioma: | Inglés
Notas: | Article history: Received August 13, 2001. / Accepted October 16, 2002.

Contenido:

ABSTRACT.
The genetic component in heat tolerance for nonreturn rate in Holsteins was estimated using an animal linear model augmented by a random regression on a temperature-humidity index (THI). Data consisted of 18,059 nonreturn rates at 45, 60, and 90 d after insemination and 81,674 first-parity test-day milk yields from 78 herds in Florida. The THI on the day of insemination or test day was added to each record. Only first-insemination records were used. The model for nonreturn rate included the effects of herd-year-season, age, days in milk, milk yield, THI as a covariable, regular additive effect, and random regression on THI for heat-tolerance additive effect. With a single-trait model, heritability estimates for NR45, NR60, and NR90 at THI = 70 for first-lactation cows were 0.006, 0.014, and 0.053, respectively. Genetic correlation between regular NR90 and heat tolerance was -0.95. A bivariate analysis for NR90 and test-day milk production yielded a correlation between regular merit and heat tolerance for NR90 of -0.35, substantially lower than by the univariate model, indicating a bias in the univariate estimates caused by ignored selection. The regular genetic correlation between NR90 and milk yield was -0.41. Genetic correlation between heat tolerance for NR90 and heat tolerance for milk yield was -0.04, indicating the need to separate selection.
© Copyright 2017 Elsevier B.V., All rights reserved.

Palabras-Clave: | Dairy cattle; Heat stress; Nonreturn rate; Temperature-humidity index.
Categoría del tema: | --

URL:

http://www.ainfo.inia.uy/digital/bitstream/item/13409/1/Jr.Dairy-Science.-2002.-1-s2.0-S0022030202743968-main.pdf
https://www.journalofdairyscience.org/article/S0022-0302(02)74396-8/pdf

Registro original: | INIA Las Brujas (LB)
Ejemplares: | LB - (12855-1) - PXI - AP - DD - PP/JR. DAIRY SCIENCE/2002 -  -  - DIS