Estimates of the complete genetic covariance matrix for traits in multi-trait genetic evaluation of Australian Hereford cattle

Estimates of covariance components among all 22 traits considered in the current multi-trait genetic evaluation of Australian Hereford cattle were obtained. Traits included 5 weight traits, 8 traits measured through live ultrasound scanning, 3 traits related to reproductive performance, and 6 carcass traits. Estimates were obtained by restricted maximum likelihood, carrying out a series of bivariate analyses. Data for each analysis were selected attempting to maximise the number of animals or animal–parent pairs that had both traits recorded. Estimates were pooled using a weighted 'iterative summing of expanded part matrices' procedure, which ensured positive semi-definite covariance matrices. Models of analyses for individual traits closely resembled those used in genetic evaluation. Results generally agreed with literature results, although estimates of genetic parameters for carcass traits that had few records available tended to fluctuate. Except for 'days to calving', heritability estimates were moderate to high for all traits. Genetic parameters for early growth were different to those for other breeds, with maternal effects for weaning weight being considerably more important and the heritability somewhat lower.

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Comparison of two live-animal ultrasound systems for genetic evaluation of carcass traits in Angus cattle

Translational Animal Science ◽

10.1093/tas/txab011 ◽

2021 ◽

Author(s):

C J Duff ◽

J H J van der Werf ◽

P F Parnell ◽

S A Clark

Keyword(s):

Carcass Traits ◽

Genetic Correlations ◽

Subcutaneous Fat ◽

Genetic Evaluation ◽

Ultrasound Scan ◽

Ultrasound Scanning ◽

Eye Muscle ◽

Angus Cattle ◽

Breeding Objective ◽

Two Systems

Abstract The improvement of carcass traits is an important breeding objective in beef cattle breeding programs. The most common way of selecting for improvement in carcass traits is via indirect selection using ultrasound scanning of selection candidates which are submitted to genetic evaluation programs. Two systems used to analyse ultrasound images to predict carcass traits are the Pie Medical Esaote Aquila (PIE) and Central Ultrasound Processing (CUP). This study compared the ability of the two systems to predict carcass traits for genetic evaluation in Australian Angus cattle. Genetic and phenotypic parameters were estimated using data from 1648 Angus steers which were ultrasound scanned twice with both systems, first at feedlot entry and then following 100 days in the feedlot. The traits interpreted from ultrasound scanning included eye muscle area (EMA), rib fat (RIB) rump fat (RUMP) and intramuscular fat (IMF). Abattoir carcass data were collected on all steers following the full feedlot feeding period of 285 days. For all ultrasound scan traits, CUP resulted in higher phenotypic and genetic variances compared to the PIE. For IMF, CUP had higher heritability at feedlot intake (0.51 for CUP compared to 0.37 for PIE) and after 100 days feeding (0.54 for CUP compared to 0.45 PIE). CUP predicted IMF also tended to have stronger correlations with the breeding objective traits of carcass IMF marbling traits, both genetically (ranging from 0.59 to 0.75 for CUP compared to 0.45 to 0.63 for PIE) and phenotypically (ranging from 0.27 to 0.43 for CUP compared to 0.19 to 0.28 for PIE). Ultrasound scan EMA were the only group of traits in which the heritabilities were higher for PIE (0.52 for PIE compared to 0.40 for CUP at feedlot intake and 0.46 for PIE compared to 0.43 for CUP at 100 days of feeding), however with similar relationships to the breeding objective carcass EMA observed. For subcutaneous fat traits of ultrasound RIB and RUMP, the heritabilites and genetic correlations to the related carcass traits were similar, with the exception being the higher heritability observed for CUP predicted RUMP at feedlot intake at 0.52 compared to 0.38 for PIE. The results from this study indicates that the CUP system, compared to PIE, provides an advantage for genetic evaluation of carcass traits in Angus cattle, particularly for the IMF and associated marbling traits.

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Genetic parameters for cow weight and condition score in Angus, Hereford, and Poll Hereford cattle

Australian Journal of Agricultural Research ◽

10.1071/ar9961251 ◽

1996 ◽

Vol 47 (8) ◽

pp. 1251 ◽

Cited By ~ 15

Author(s):

DJ Johnston ◽

H Chandler ◽

HU Graser

Keyword(s):

Body Condition ◽

Evaluation System ◽

Field Data ◽

Genetic Parameters ◽

Body Condition Score ◽

Genetic Correlations ◽

Genetic Evaluation ◽

Multiple Trait ◽

Hereford Cattle ◽

Condition Score

Heritabilities and genetic correlations for cow weight and body condition score were estimated from field data for 3 beef breeds in Australia. In all, 8177 cows of mixed ages were weighed and scored for body condition at calf weaning time in seedstock herds as part of a large research project. The average weaning age was 212, 221, and 218 days for Angus, Hereford, and Poll Hereford, respectively. Cow weights and condition scores were analysed separately for each breed and estimates of genetic parameters were obtained by Restricted Maximum Likelihood (REML). Cow weight and condition score were moderately heritable: h2 = 0.43 and 0.21 for Angus, 0.39 and 0.14 for Hereford, and 0.48 and 0.17 for Poll Hereford. The genetic correlation between CW and CS was 0.49, 0.65, and 0.58 for Angus, Hereford, and Poll Hereford, respectively. There is potential for providing a genetic evaluation for cow weight using field data in Australian beef cattle. Its modelling for inclusion in a multiple trait genetic evaluation system such as BREEDPLAN is discussed.

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Covariance matrices for growth traits of Australian Polled Hereford cattle

Animal Science ◽

10.1017/s0003356100006589 ◽

1993 ◽

Vol 57 (1) ◽

pp. 37-45 ◽

Cited By ~ 16

Author(s):

K. Meyer

Keyword(s):

Environmental Effects ◽

Genetic Parameters ◽

Growth Traits ◽

Genetic Correlations ◽

Data Sets ◽

Model Data ◽

Weaning Weight ◽

Hereford Cattle ◽

Final Weight ◽

Covariance Components

AbstractEstimates of covariance components due to direct and maternal effects among birth, weaning, yearling and final weight for Australian Polled Herefords were obtained by restricted maximum likelihood fitting an animal model. Data were obtained from commercial herds participating in the National Beef Recording Scheme and an across-herd genetic evaluation service. Analyses were carried out considering nine subsets of data, each comprising at least 3000 weaning, 1000 yearling and 500 final weight records which yielded a total of 30 506,17 105 and 9486 records for the three weights, respectively. Estimates of variances and genetic parameters varied considerably between data sets. Both genetic and permanent environmental effects were found to affect all traits except final weights significantly, with maternal environmental effects explaining proportionately more than 0·20 of the total variation in weaning weight. Estimates of the direct-maternal genetic correlation were consistently negative and moderate to strong, ranging from -0·34 to -0·82 for weaning weight. Maternal correlations between weaning and yearling weights were close to unity. Estimates of the direct genetic correlations among the three later weights were 0·8 or larger. Problems with this kind of analysis are discussed.

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PSXII-33 The Effect of Log Transformation on Carcass Data Measured by Ultrasound

Journal of Animal Science ◽

10.1093/jas/skaa278.451 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 249-249

Author(s):

Tae Jeong Choi ◽

Byoungho Park ◽

Hannah Oh ◽

Oh Sang-Hyon

Keyword(s):

Genetic Parameters ◽

Carcass Traits ◽

Genetic Correlations ◽

Fat Content ◽

Genetic Evaluation ◽

Muscle Area ◽

Log Transformation ◽

Significant Difference ◽

Native Cattle ◽

Genetic Evaluations

Abstract This study is to evaluate the effect of log transformation on ultrasound data records on the genetic evaluation of Hanwoo (Korean native cattle) proven bulls. Three different scenarios were established: genetic evaluations using (A) only yearling weights (YW; n = 15,665) and carcass traits (CT); (B) YW, CT and raw ultrasound data at 12 and 24 months of age; and (C) YW, CT and log transformed data of raw ultrasound data records in (B). Carcass traits include carcass weight (CW; n = 6,526), loin muscle area (LMA; n = 6,820), backfat thickness (BFT; n = 6,723), and intramuscular fat (IMF; n = 5,037). Ultrasound traits include LMA, BFT, and fat content (FC; %), which were measured with Aquila Vet (Pie Medical) between the 12th and 13th rib. REMLF90 was used to estimate genetic parameters such as heritability and genetic correlations. Rank correlations of breeding values were analyzed using SAS 9.2. The heritability of YW was the highest at (B) and reduced by 0.2% at (C). The heritability of CW was higher at (B) and (C) than at (A) by 0.6%. In the case of BFT and IMF, (B) and (C) was 0.5% and 0.6% higher than (A) and -1.0% and -0.8% lower than (A), respectively. The heritabilities regarding ultrasound traits at 12 months of age were higher for LMA and FC in (C) than (B), and higher for BFT in (B) than (C). In the case of 24 months of age, (C) was higher in all ultrasound traits than (B). The rank correlations of (B) and (C) at 12 months were 0.995 in ultrasound LMA and 0.991 in ultrasound BFT. For 24 months, the correlations were 0.989 and 0.986, respectively. In conclusion, the results didn’t provide us with evidence of a significant difference in genetic evaluations among different scenarios regarding log transformation on ultrasound data records of carcass traits.

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Polymorphisms of the IGF1R gene and their genetic effects on chicken early growth and carcass traits

BMC Genetics ◽

10.1186/1471-2156-9-70 ◽

2008 ◽

Vol 9 (1) ◽

pp. 70 ◽

Cited By ~ 23

Author(s):

Mingming Lei ◽

Xia Peng ◽

Min Zhou ◽

Chenglong Luo ◽

Qinghua Nie ◽

...

Keyword(s):

Carcass Traits ◽

Early Growth ◽

Genetic Effects

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Genetic parameters of growth and in vivo computerized tomography based carcass traits in Pannon White rabbits

Livestock Science ◽

10.1016/j.livsci.2006.03.009 ◽

2006 ◽

Vol 104 (1-2) ◽

pp. 46-52 ◽

Cited By ~ 14

Author(s):

I. Nagy ◽

N. Ibáñez ◽

R. Romvári ◽

W. Mekkawy ◽

Sz. Metzger ◽

...

Keyword(s):

Computerized Tomography ◽

Genetic Parameters ◽

Carcass Traits

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Selection for rate and efficiency of lean gain in Hereford cattle 1. Selection pressure applied and direct responses

Animal Science ◽

10.1017/s0003356100005122 ◽

1990 ◽

Vol 51 (1) ◽

pp. 23-34 ◽

Cited By ~ 21

Author(s):

R. A. Mrode ◽

C. Smith ◽

R. Thompson

Keyword(s):

Genetic Parameters ◽

Control Line ◽

Correlated Responses ◽

Direct Response ◽

Lean Growth ◽

Hereford Cattle ◽

Frozen Semen ◽

Phenotypic Standard Deviation ◽

Selection For ◽

Selection Of

ABSTRACTSelection of bulls for rate and efficiency of lean gain was studied in a herd of Hereford cattle. There were two selection lines, one selected for lean growth rate (LGR) from birth to 400 days and the other for lean food conversion ratio (LFCR) from 200 to 400 days of age, for a period of 8 years. A control line bred by frozen semen from foundation bulls was also maintained. Generation interval was about 2·4 years and average male selection differentials, per generation were 1·2 and — 1·1 phenotypic standard deviation units for LGR and LFCR respectively.Genetic parameters and responses to selection were estimated from the deviation of the selected lines from a control line and by restricted maximum likelihood (REML) techniques on the same material. Realized heritabilities were 0·40 (s.e. 0·12) for LGR and 0·40 (s.e. 0·13) for LFCR using the control line. Corresponding estimates from REML were 0·42 (s.e. 0·10) and 0·37 (s.e. 0·14). The estimate of the genetic correlation between LGR and LFCR was about — 0·69 (s.e. 0·12) using REML.The estimates of direct annual genetic change using deviations from the control were 3·6 (s.e. 1·3) g/day for LGR and — 0·14 (s.e. 0·07) kg food per kg lean gain for LFCR. Corrsponding estimates from REML were similar but more precisely estimated. The correlated responses for LFCR in the LGR line was higher than the direct response for LFCR.

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