scholarly journals Genetic parameters for docility, weaning weight, yearling weight, and intramuscular fat percentage in Hereford cattle1

2016 ◽  
Vol 94 (1) ◽  
pp. 21-27 ◽  
Author(s):  
J. A. Torres-Vázquez ◽  
M. L. Spangler
2017 ◽  
Vol 96 (2) ◽  
pp. 282-287 ◽  
Author(s):  
M. Jiang ◽  
W.L. Fan ◽  
S.Y. Xing ◽  
J. Wang ◽  
P. Li ◽  
...  

2002 ◽  
Vol 80 (8) ◽  
pp. 2017 ◽  
Author(s):  
R. L. Sapp ◽  
J. K. Bertrand ◽  
T. D. Pringle ◽  
D. E. Wilson

2016 ◽  
Vol 133 (5) ◽  
pp. 422-428 ◽  
Author(s):  
L. Leng ◽  
H. Zhang ◽  
J.Q. Dong ◽  
Z.P. Wang ◽  
X.Y. Zhang ◽  
...  

2021 ◽  
pp. 17-22
Author(s):  
Afees Abiola Ajasa ◽  
Imre Füller ◽  
Barnabás Vágó ◽  
István Komlósi ◽  
János Posta

The aim of the current research was to estimate variance components and genetic parameters of weaning weight in Hungarian Simmental cattle. Weaning weight records were obtained from the Association of Hungarian Simmental Breeders. The dataset comprised of 44,278 animals born from 1975 to 2020. The data was analyzed using the restricted maximum likelihood methodology of the Wombat software. We fitted a total of six models to the weaning weight data of Hungarian Simmental cattle. Models ranged from a simple model with animals as the only random effect to a model that had maternal environmental effects as additional random effects as well as direct maternal genetic covariance. Fixed effects in the model comprised of herd, birth year, calving order and sex. Likelihood ratio test was used to determine the best fit model for the data. Results indicated that allowing for direct-maternal genetic covariance increases the direct and maternal effect dramatically. The best fit model had direct and maternal genetic effects as the only random effect with non-zero direct-maternal genetic correlation. Direct heritability, maternal heritability and direct maternal correlation of the best fit model was 0.57, 0.16 and -0.78 respectively. The result indicates that problem of (co-)sampling variation occurs when attempting to partition additive genetic variance into direct and maternal components.


2007 ◽  
Vol 7 (2) ◽  
pp. 12 ◽  
Author(s):  
Rodrigo Alfredo Martínez ◽  
Juan Esteban Pérez ◽  
Teófilo Herazo

<p>Se establecieron componentes de varianza, así como parámetros fenotípicos y genéticos, respecto de las variables ‘peso al nacimiento’, ‘peso al destete’ (ajustado a los 270 días) y ‘peso a los 480 días’ en un hato del ganado criollo colombiano Costeño con Cuernos. Se analizaron 2.281 registros de pesos al nacer, 1.722 de pesos al destete  y 1.086 de pesos ajustados a los 480 días utilizando la metodología de máxima verosimilitud restringida (DFREML). También se ajustó un modelo animal que incluyó efectos genéticos directos, maternos y de ambiente permanente, asumiendo como efectos fijos el año de nacimiento, el sexo del ternero y el número de partos de la madre; finalmente, se estimaron los parámetros genéticos ‘heredabilidad’, ‘repetibilildad’ y se establecieron correlaciones genéticas y fenotípicas. Se reportan bajas estimaciones de heredabilidad de los efectos directos, que varían entre 0,17 ± 0,001 y 0,21 ± 0,074 para los pesos al nacer y al destete, respectivamente; así mismo, fue baja la heredabilidad de los efectos genéticos maternos con relación al peso al nacimiento, aunque estos estimados aumentaron respecto de los pesos al nacer y al destete. Las correlaciones entre efectos directos y maternos fueron negativas, pero el mayor valor se encontró para el peso al nacimiento (-0,89). La contribución del ambiente permanente como proporción de la varianza fenotípica total fue baja y disminuyó a medida que aumentó la edad del animal.</p><p> </p><p><strong>Genetic and phenotypic evaluation to characterize growth traits of the native Colombian breed Costeño con Cuernos</strong></p><p>For a herd of native Colombian breed of cattle -Costeño con Cuernos (CCC)- estimates of variance components for phenotypic and genetic parameters were obtained for birth weight, weight at weaning (adjusted to 270 days) and weight at 480 days. Using the restricted maximum likelihood (REMI) methodology, 2281 birth weight records (PN), 1722 weaning weight records and 1086 weight records adjusted to 480 days were analyze by fitting a model which included direct and maternal genetics effects as well as permanent environmental effects, assuming that fixed effects were year of birth weight, calf gender and the mother number of births. The genetic parameters for heritability, repeatability, genetic and phenotypic correlation were estimated and genotypic and phenotypic correlation was established. Heritability estimates for direct effects are low and range from 0.17 ± 0.001 and 0.21 ± 0.074 for birth and weaning weight respectively; while estimates for maternal genetics effects were also low for PN, they were higher for weaning weight and weight at 480 days. There was a negative correlation between direct and maternal effects, and the higher value was for PN (-0.89). The contribution of the variable permanent environment measured as the contribution of the phenotypic variance was low and diminished as animal age increased.</p>


1998 ◽  
Vol 49 (2) ◽  
pp. 285 ◽  
Author(s):  
S. Baud ◽  
C. M. Wade ◽  
M. E. Goddard

Carcass quality characteristics were measured on 511 steers of 4 breeds that were destined for the Japanese market. All steers had carcass measurements taken at the 10th/11th rib interface, while 103 steers had additional measurements made on the same characteristics at the 5th/6th rib interface. Australian marbling score, longissimus muscle area, intramuscular fat percentage, intramuscular water content, Japanese intermuscular fat thickness, Japanese subcutaneous fat thickness, Japanese rib thickness, and meat pH were measured in the study. These measurements allowed the phenotypic relationships between the different carcass quality traits measured at the 10th/11th rib interface to be calculated. Significant positive correlations were observed among measurements of carcass fatness, and significant negative correlations were observed between carcass fatness and carcass water content. Angus and Murray Grey cattle had higher levels of marbling and intramuscular fat than Hereford and Poll Hereford cattle The data enabled Australian, USDA, and Japanese marbling standards to be compared on the basis of intramuscular fat percentage determined by an ether extraction process. Differences between the same carcass characteristics taken at 5th/6th and 10/11th rib interfaces of the longissimus dorsi were estimated from the 103 steers measured at both sites. Correlations between the rib sites were high for marbling, intramuscular fat, and intramuscular water, but low for longissimus muscle area, intermuscular fat thickness, and pH.


1993 ◽  
Vol 44 (2) ◽  
pp. 179 ◽  
Author(s):  
GP Davis

This paper reviews published estimates of genetic parameters for traits of growth, reproduction and resistance to environmental stresses for Bos indicus and Zebu derived breeds in northern Australia. Most published estimates of heritabilities for growth and reproduction traits were higher for tropically adapted breeds in northern Australia than for Bos taurus breeds in temperate Australia. Weighted mean estimates of heritabilities for the direct component of weaning weight were 39% for the Brahman breed and 30% for Zebu-derived breeds in northern Australia compared with 13% for Bos taurus breeds in temperate areas of Australia. Mean estimates for the maternal component of weaning weight were 5, 24 and 13% respectively. Mean heritabilities for yearling and 550 day weights for Zebu derived breeds in northern Australia (24 and 25%) were similar to those for Bos taurus breeds in temperate areas, though estimates for Brahmans were higher (39 and 39%). Published estimates of heritabilities of later weights (700 and 900 days), which are most relevant to northern Australian production systems, were rare but averaged between 32 and 45% for Zebu-derived breeds and Brahmans. Weighted mean heritability for female calving success was 14% and for realised bull fertility was 5%. Published estimates of heritabilities of scrota1 circumference averaged 31%, and testosterone response to GNRH stimulation was 52%. Heritabilities of resistance to various environmental stresses were all moderate with weighted means between 20 and 34%. Genetic correlations between growth, reproduction and resistance to environmental stresses are also reviewed. There appears to be predictable variation in estimates of parameters between breeds in different environments which is related to level of resistance to environmental stresses, and this is likely to affect the prediction of breeding values for cattle in northern Australia.


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