scholarly journals Genetic analysis of calving traits by the multi-trait individual animal model

2016 ◽  
Vol 99 (1) ◽  
pp. 427-442 ◽  
Author(s):  
J.I. Weller ◽  
E. Ezra
Keyword(s):  
Animal Model ◽  
Genetic Analysis ◽  
Individual Animal ◽  
Calving Traits

Genetic analysis of docility score of Australian Angus and Limousin cattle

2018 ◽  
Vol 58 (2) ◽  
pp. 213 ◽  
Author(s):  
S. F. Walkom ◽  
M. G. Jeyaruban ◽  
B. Tier ◽  
D. J. Johnston
Keyword(s):  
Adverse Effect ◽  
Animal Model ◽  
Genetic Analysis ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Costs ◽  
Breeding Value ◽  
Maternal Behaviour ◽  
Production Traits ◽  
Subjective Score

The temperament of cattle is believed to affect the profitability of the herd through impacting production costs, meat quality, reproduction, maternal behaviour and the welfare of the animals and their handlers. As part of the national beef cattle genetic evaluation in Australia by BREEDPLAN, 50 935 Angus and 50 930 Limousin calves were scored by seedstock producers for temperament using docility score. Docility score is a subjective score of the animal’s response to being restrained and isolated within a crush, at weaning, and is scored on a scale from 1 to 5 with 1 representing the quiet and 5 the extremely nervous or anxious calves. Genetic parameters for docility score were estimated using a threshold animal model with four thresholds (five categories) from a Bayesian analysis carried out using Gibbs sampling in THRGIBBS1F90 with post-Gibbs analysis in POSTGIBBSF90. The heritability of docility score on the observed scale was 0.21 and 0.39 in Angus and Limousin, respectively. Since the release of the docility breeding value to the Australian Limousin population there has been a favourable trend within the national herd towards more docile cattle. Weak but favourable genetic correlations between docility score and the production traits indicates that docility score is largely independent of these traits and that selection to improve temperament can occur without having an adverse effect on growth, fat, muscle and reproduction.

Genetic and phenotypic trends in production traits in the United Kingdom (UK) dairy herd

1998 ◽  
Vol 1998 ◽  
pp. 191-191
Author(s):  
C. M. Lindberg ◽  
G. J. T. Swanson ◽  
R. A. Mrode
Keyword(s):  
Animal Model ◽  
United Kingdom ◽  
Milk Fat ◽  
Dairy Industry ◽  
Dairy Herd ◽  
Production Traits ◽  
Individual Animal ◽  
Know How ◽  
The United Kingdom ◽  
Breeding Schemes

It is important for the dairy industry to be aware of the consequences of past selection policies. This can provide guidance on how to improve or change current breeding schemes. In addition it is important to know how much of current progress is due to breeding and how much to management. The objective of the study was to analyse genetic and phenotypic trends for the production traits (milk, fat and protein) using the results from the latest UK Individual Animal Model evaluations.

Results of multivariate individual animal model genetic evaluations of british pedigree beef cattle

1997 ◽  
Vol 65 (2) ◽  
pp. 199-207 ◽  
Author(s):  
R. E. Crumps ◽  
G. Simm ◽  
D. Nicholson ◽  
R. H. Findlay ◽  
J. G. E. Bryan ◽  
...  
Keyword(s):  
Animal Model ◽  
Birth Weight ◽  
Beef Cattle ◽  
Fixed Effects ◽  
Breeding Value ◽  
Individual Animal ◽  
Group Sex ◽  
The Uk ◽  
Genetic Evaluations ◽  
Genetic Trends

AbstractThis paper reports the procedures put into place in the UK for the genetic evaluation of pedigree beef cattle and estimation of genetic trends using a comprehensive model to allow critical analysis of progress made under previous data recording schemes. Live weights of Simmental, Limousin, Charolais, South Devon and Aberdeen Angus beef cattle, recorded by the Meat and Livestock Commission (MLC) from 1970 to 1992 were analysed, as part of a project to introduce best linear unbiased predictions (BLUP) of breeding value in the British beef industry. Birth weights were available from MLC or the relevant breed society, (4000 to 84000 records, depending on the breed) and 200- and 400-day weights were estimated by within-animal linear regression on all available weights (resulting in 8000 to 48000 records per breed). Animals were retrospectively assigned to contemporary groups within herds, separately for each trait, taking account of observed calving patterns. Records were adjusted to correct for heterogeneity of variance between herds. BLUP evaluations were then performed within breed, fitting a multivariate individual animal model. In addition to additive direct genetic effects, additive maternal genetic and dam permanent environmental effects were included for birth weight and 200-day weight. Unknown parents were assigned to genetic groups, based on estimated date of birth. The model included fixed effects for contemporary group, sex, month of birth, birth type (single or multiple), embryo transfer births, fostered calves, breed of dam, proportion purebred and age of dam. Genetic trends were estimated by regressing estimated breeding values for animals on their year of birth. Trends in birth weight, 200-day weight and 400-day weight between 1970 and 1992 were approximately 0·09, 0·73 and 1·38 kg per annum respectively for the Charolais breed; 0·08, 0·76 and 1·33 kg per annum for the Simmental; 0·06, 0·53 and 0·89 kg per annum for the Limousin; 0·12, 1·02 and 1·86 kg per annum for the Aberdeen Angus; and 0·03, 0·38 and 0·82 kg per annum for the South Devon breed.

Estimation of direct additive and maternal additive genetic effects for weaning weight in Mashona cattle of Zimbabwe using an individual animal model

1995 ◽  
Vol 60 (1) ◽  
pp. 41-48 ◽  
Author(s):  
C. T. Khombe ◽  
J. F. Hayes ◽  
R. I. Cue ◽  
K. M. Wade
Keyword(s):  
Animal Model ◽  
Variance Components ◽  
Mean Value ◽  
Individual Animal ◽  
Breeding Values ◽  
General Decline ◽  
Derivative Free ◽  
The Mean ◽  
Future Revision ◽  
Additive Genetic Effects

AbstractWeaning weights (or weight nearest to 205 days of age) from 8086 Mashona calves were collected from seven herds covering the period 1976 to 1988. Estimates of (co)variance components were obtained by restricted maximum likelihood using a derivative free algorithm and fitting an individual animal model. Estimates of direct additive heritability, maternal additive heritability, their correlation, total heritability and repeatability, obtained under two models were 0·243 and 0·281, 0·113 and 0·392, –0·282 and –0·269, 0·252 and 0·298, and 0·409 and 0·573, respectively. Trends within herd were estimated from the mean value of progeny born within a particular year. There were no significant trends in direct additive breeding values. A general decline in maternal breeding values was observed. Only one herd (herd 1) had a significant eroiyonmeYital freni (0·385 kg/year). It IMS emphftsilfiti that any future revision of the method used to improve the weaning weights of beef cattle should also improve their maternal breeding values.

Individual animal model estimates of genetic parameters for performance test traits of male and female landrace pigs tested in a commercial nucleus herd

1997 ◽  
Vol 65 (2) ◽  
pp. 275-283 ◽  
Author(s):  
R. E. Crump ◽  
C. S. Haley ◽  
R. Thompson ◽  
J. Mercer
Keyword(s):  
Animal Model ◽  
Performance Test ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Genetic Effect ◽  
Data Sets ◽  
Environment Interaction ◽  
Individual Animal ◽  
Genetic Progress ◽  
The Common

AbstractEstimates of heritabilities, common litter of birth effects and additive maternal genetic effects were produced for ultrasonic backfat depth, average daily food intake, average daily gain and food conversion ratio of Landrace boars and gilts. Boars and gilts were performance tested under different regimes. A bivariate derivative-free restricted maximum likelihood procedure was used to estimate genetic correlations between the performance test traits as recorded in the two sexes.Heritability estimates from the analysis including the common litter of birth effect tended to be towards the low end of the range of recently published estimates. This may reflect either population specific effects, such as effects of long-term selection, or the use of an individual animal model.Estimates of the common litter of birth effect were around 0·05, and generally had a significant effect upon the fit of the model, while additive maternal genetic effect estimates were negligible. Therefore, it is expected that omission of maternal effects from models for evaluation by best linear unbiased prediction will not hinder genetic progress. Inclusion of common litter of birth effects would be recommended, although this result may not hold for populations given food ad libitum.The estimates of genetic correlations between performance test traits of boars and gilts indicate that the levels of genotype-environment interaction (G × E) and genotype-sex interaction were low across most traits and data sets, with all genetic correlation estimates lying between 0·8 and 1·0. The lowest estimates of the genetic correlations, which were observed in data sets where the environments appeared to differ most, indicate that G × E interactions may be a problem in populations where males and females are subject to test regimes with greater differences than those seen here.

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