The achievement of a given carcass specification is under moderate genetic control in cattle

Abstract The objective of the present study was to estimate the genetic parameters associated with the achievement of desirable weight, conformation, and fat specifications, represented by a series of binary traits. The desired specifications were those stipulated by Irish beef processors, in accordance with the EUROP carcass grading system, and were represented by a carcass weight between 270 and 380 kg, a fat score between 2+ and 4= (between 6 and 11 on a 15-point scale), and a conformation score of O= or better (≥5 on a 15-point scale). Using data from 58,868 beef carcasses, variance components were estimated using linear mixed models for these binary traits, as well as their underlying continuous measures. Heritability estimates for the continuous traits ranged from 0.63 to 0.73; heritability estimates for the binary traits ranged from 0.05 to 0.19. An additional trait was defined to reflect if all desired carcass specifications were met. All genetic correlations between this trait and the individual contributing binary traits were positive (0.38 to 0.87), while all genetic correlations between this trait and the continuous carcass measures were negative (−0.87 to −0.07). The genetic parameters estimated in the present study signify that potential exists to breed cattle that more consistently achieve desirable carcass metrics at harvest.

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Genetic parameters for fatty acids in intramuscular fat from feedlot-finished Nelore carcasses

Animal Production Science ◽

10.1071/an16107 ◽

2018 ◽

Vol 58 (2) ◽

pp. 234 ◽

Cited By ~ 3

Author(s):

Carolyn Aboujaoude ◽

Angélica Simone Cravo Pereira ◽

Fabieli Louise Braga Feitosa ◽

Marcos Vinicius Antunes de Lemos ◽

Hermenegildo Lucas Justino Chiaia ◽

...

Keyword(s):

Fatty Acids ◽

Genetic Correlation ◽

Genetic Parameters ◽

Genetic Correlations ◽

Intramuscular Fat ◽

Zebu Cattle ◽

Fa Composition ◽

Heritability Estimates ◽

The Individual ◽

Long Chain

The aim of the present study was to estimate covariance components and genetic parameters for beef fatty acid (FA) composition of intramuscular fat in the longissimus thoracis muscle in Nelore bulls finished in feedlot. Twenty-two FAs were selected. The heritability estimates for individual FAs ranged from 0.01 to 0.35. The heritability estimates for myristic (0.25 ± 0.09), palmitic (0.18 ± 0.07), oleic (0.28 ± 0.09), linoleic (0.16 ± 0.06) and α-linolenic (0.35 ± 0.10) FAs were moderate. Stearic, elaidic, palmitoleic, vaccenic, conjugated linoleic acid, docosahexanoic, eicosatrienoic and arachidonic FAs had heritability estimates below 0.15. The genetic-correlation estimates between the individual saturated FAs (SFAs) were low and negative between myristic and stearic FAs (–0.22 ± 0.84), moderate between palmitic and myristic FAs (0.58 ± 0.56) and negative between palmitic and stearic FAs (–0.69 ± 0.45). The genetic correlations between the individual long-chain polyunsaturated FAs (PUFAs) were positive and moderate (>0.30). However, the genetic-correlation estimates between long-chain PUFAs and α-linolenic acid were low (<0.30), except for the correlation between arachidonic and α-linolenic acids. The genetic correlation estimates of the sums of SFAs with monounsaturated fatty acids and omega 6 FAs were low (0.25 ± 0.59 and –0.02 ± 0.51 respectively), high with PUFAs and omega 9 FAs (–0.85 ± 0.15 and 0.86 ± 0.17 respectively) and moderate with omega 3FAs (–0.67 ± 0.26). The present study demonstrated the existence of genetic variation and, hence, the possibility to increase the proportion of healthy and favourable beef FAs through selection. The results obtained in the study have provided knowledge to elucidate the additive genetic influence on FA composition of intramuscular fat. In addition, genetic-relationship estimates of intramuscular FA profile help seek strategies for genetic selection or genetic-based diet management to enhance the FA profile in Zebu cattle.

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Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽

10.1093/genetics/143.3.1409 ◽

1996 ◽

Vol 143 (3) ◽

pp. 1409-1416 ◽

Cited By ~ 1

Author(s):

Kenneth R Koots ◽

John P Gibson

Keyword(s):

Genetic Correlation ◽

Genetic Parameters ◽

Genetic Parameter ◽

Genetic Correlations ◽

Phenotypic Correlation ◽

Parameter Estimates ◽

Sampling Variance ◽

Phenotypic Correlations ◽

Genetic And Phenotypic Correlations ◽

Heritability Estimates

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.

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Phenotypic and genetic parameters for reproductive performance in a synthetic line of sheep

The Journal of Agricultural Science ◽

10.1017/s0021859600031920 ◽

1981 ◽

Vol 96 (1) ◽

pp. 107-113 ◽

Cited By ~ 11

Author(s):

T. G. Martin ◽

D. Nicholson ◽

C. Smith ◽

D. I. Sales

Keyword(s):

Reproductive Performance ◽

Genetic Parameters ◽

Genetic Correlations ◽

Reproductive Traits ◽

Direct Selection ◽

Sex Distribution ◽

Regression Methods ◽

Litter Weight ◽

Heritability Estimates ◽

Synthetic Line

SUMMARYData on 902 ewes (1755 records) bom over 7 years in the synthetic ABRO Dam Line were analysed by least squares. Reproductive traits of the ewe were not affected by whether she was a single or a twin or by the age of her dam. Ewe age had major effects on all reproductive traits. Litter weight traits were affected by the sex distribution and the age of the litter when weighed.Heritability estimates, both by half sib and regression methods, were low for litter size, low to moderate for litter weights, and higher for ewe and fleece weights. Genetic correlations among the litter-weight traits were high. Together with the heritability estimates, they indicated that selection on litter weight at birth (and perhaps other traits) might give a greater change in total litter weight at weaning, the main measure of ewe productivity and the objective in improvement, than would direct selection.

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Genetic parameters for terminal sires estimated using data of progeny from Border Leicester × Merino ewes

Australian Journal of Agricultural Research ◽

10.1071/ar9950703 ◽

1995 ◽

Vol 46 (4) ◽

pp. 703

Author(s):

PA Kenney ◽

ME Goddard ◽

LP Thatcher

Keyword(s):

Genetic Parameters ◽

Selection Index ◽

Genetic Correlations ◽

Subcutaneous Fat ◽

Muscle Area ◽

Eye Muscle ◽

Bone Length ◽

Selection For ◽

Using Data ◽

Omental Fat

Three and a half thousand lambs from Border Leicester x Merino ewes mated to 133 sires from five Poll Dorset, one White Suffolk, one Siromt, two Meridale and four Merino studs were slaughtered, their carcasses halved and one side divided into six primals. Subcutaneous fat was dissected from all six primals, and bone from only the three rear primals. There were four slaughter groups: average slaughter weights of 30 and 35 kg for ewes and 35 and 45 kg for cryptorchids. Heritabilities and phenotypic and genetic correlations for all traits measured (>50) are published in an appendix. Where comparisons were available, estimates were similar to those for purebred animals. Genetic parameters for various assessments of fat were similar except for channel and omental fat. The GR fat depth was the best predictor for total subcutaneous fat, cannon bone length for total bone, and eye muscle area for total soft tissue. Carcass weight and GR appear to be the most important measurements for use in selection for breeding of sires for the prime lamb industry. Slaughter weight and fat depth at the C site could be used as suitable alternatives on live animals. Production of lean meat is not likely to be increased greatly by including measurements other than liveweight and GR in a selection index. Of the other measurements bone length and eye muscle measurements showed most promise.

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Estimation of genetic parameters in beef cattle from records of performance

Australian Journal of Experimental Agriculture ◽

10.1071/ea9750731 ◽

1975 ◽

Vol 15 (77) ◽

pp. 731 ◽

Cited By ~ 1

Author(s):

K Baharin ◽

RG Beilharz

Keyword(s):

Growth Rates ◽

Genetic Parameters ◽

The Other ◽

Female Progeny ◽

Intra Class Correlation ◽

Significant Difference ◽

Heritability Estimates ◽

The Individual ◽

Estimation Of Genetic Parameters ◽

Calving Performance

An analysis of the growth and calving performance from a crossbreeding program involving four breeds of sires (Angus, Hereford, Friesian and Shorthorn) mated to three breeds of purebred dams (Angus, Hereford and Shorthorn) and three types of crossbred heifers (Angus x Hereford, Friesian x Angus and Friesian x Hereford) during the 1971 and 1972 calving seasons is presented. The performance of the individual breeds of dams and sires were evaluated from the size and growth rate of their progeny at birth, to weaning and post-weaning, as well as from the performance of the dams at calving measured in terms of incidence of difficult calving, percentage of calves dead at birth and twinning rate. Heritability estimates calculated from intra-class correlation of paternal half-sibs were compared from records obtained from purebred calves and from crossbred calves. Crossbred calves were heavier than the purebred calves at birth and grew faster between birth and weaning. After weaning, crossbred heifers grew significantly faster than the purebreds but no significant difference was observed among the steers. There was no significant difference in performance of crossbred calves produced by the purebred and crossbred dams. Calves from the Friesian sires and Friesian cross dams were heavier at birth than calves produced by the other three breeds of beef sires or the beef crossbred dams and they grew faster to weaning. Between weaning and yearling age both the crossbred steers and heifers from the Friesian sires continued to surpass the performance of the beef breeds of sires but there were no significant differences in the performance of three-breed-cross calves of the Friesian cross dams and the Angus x Hereford dams. Heritability estimates of growth rates calculated from data on the performance of the crossbred progeny generally were lower than those calculated from data of the purebred progeny. Higher estimates of heritability were obtained from the data of female progeny than from male progeny for birth weight but the trend was reversed for growth rates between birth to weaning and from weaning to yearling age.

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Comparison of models for estimating genetic parameters and predicting breeding values for birth weight and calving ease in Czech Charolais cattle

Czech Journal of Animal Science ◽

10.17221/7529-cjas ◽

2014 ◽

Vol 59 (No. 7) ◽

pp. 302-309 ◽

Cited By ~ 2

Author(s):

L. Vostrý ◽

Z. Veselá ◽

A. Svitáková ◽

H. Vostrá Vydrová

Keyword(s):

Animal Model ◽

Birth Weight ◽

Beef Cattle ◽

Fixed Effects ◽

Genetic Parameters ◽

Genetic Correlations ◽

Genetic Effects ◽

Parameters Estimation ◽

Calving Ease ◽

Heritability Estimates

The most appropriate model for genetic parameters estimation for calving ease and birth weight in beef cattle was selected. A total of 27 402 field records were available from the Czech Charolais breed. For estimation of genetic parameters for calving ease and body weight, three bivariate models were tested: a linear-linear animal model (L-LM) with calving ease classified into four categories (1 – easy; 2–4 – most difficult), a linear-linear animal model (SC-LM) in which calving ease scores were transformed into Snell scores (Snell 1964) and expressed as percentage of assisted calving (ranging 0–100%), and a bivariate threshold-linear animal model (T-LM) with calving ease classified into four categories (1 – easy, 2–4 – most difficult). All tested models included fixed effects for contemporary group (herd × year × season), age of dam, sex and breed of a calf. Random effects included direct and maternal genetic effects, maternal permanent environmental effect, and residual error. Direct heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.096 ± 0.013 to 0.226 ± 0.024 and from 0.210 ± 0.024 to 0.225 ± 0.026, respectively. Maternal heritability estimates for calving ease and birth weight were, with the use of L-LM, SC-LM, and T-LM, from 0.060 ± 0.031 to 0.104 ± 0.125 and from 0.074 ± 0.041 to 0.075 ± 0.040, respectively. Genetic correlations of direct calving ease with direct birth weight ranged from 0.46 ± 0.06 to 0.50 ± 0.06 for all tested models; whereas maternal genetic correlations between these two traits ranged from 0.24 ± 0.17 to 0.25 ± 0.53. Correlations between direct and maternal genetic effects within-trait were negative and substantial for all tested models (ranging from –0.574 ± 0.125 to –0.680 ± 0.141 for calving ease and from –0.553 ± 0.122 to –0.558 ± 0.118 for birth weight, respectively), illustrating the importance of including this parameter in calving ease evaluations. Results indicate that any of the tested models could be used to reliably estimate genetic parameters for calving ease for beef cattle in the Czech Republic. However, because of advantages in computation time and practical considerations, genetic analysis using SC-LM (transformed data) is recommended.

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Genetic relationships between visual and objective measures of carcass composition in crossbred lambs

Animal Science ◽

10.1017/s1357729800051407 ◽

1999 ◽

Vol 69 (3) ◽

pp. 553-561 ◽

Cited By ~ 17

Author(s):

H. E. Jones ◽

G. Simm ◽

W. S. Dingwall ◽

R. M. Lewis

Keyword(s):

No Value ◽

Genetic Relationships ◽

Genetic Correlations ◽

Subcutaneous Fat ◽

Carcass Composition ◽

Objective Measures ◽

Lean Growth ◽

Combining Data ◽

Heritability Estimates ◽

Using Data

AbstractThe aim of this study was to estimate genetic and phenotypic (co)variances between objective measures and carcass visual scores, as a test of the potential value of visual scores in selection programmes to improve carcass composition in crossbred lambs. In each of 1986, 1987 and 1988, 22 Suffolk rams were chosen with either high or low scores on an index designed to increase lean growth rate. These rams were joined with 18 to 20 crossbred ewes each and their lambs were grown on grass to one of three target live weights (35·5, 41·5 and 47·0 kg) for slaughter. The carcasses of 1881 lambs were visually scored for overall conformation and fatness using the standard Meat and Livestock Commission methods. Additionally, a more detailed 15-point scale assessment of conformation and a direct visual score of subcutaneous fat on the carcass were taken on 1252 lambs during the latter 2 years of the study. Carcass composition was estimated by dissection of a shoulder joint into lean, fat and bone. The possibility of combining data collected on lambs slaughtered at each of the three target live weights, for the estimation of genetic parameters was investigated. Results indicated that heritability estimates for a trait using data collected within each of the slaughter groups were homogeneous. Genetic correlations between records collected for a trait within each of the slaughter groups were not significantly different from one. These results indicated that data collected at each of the target slaughter weights could justifiably be combined. Heritability estimates were generally higher for shoulder tissue proportions (0·3) than for visual scores (0-2). Genetic correlations between all conformation scores and tissue proportions were not significantly different from 0 and therefore of little or no value in predicting carcass composition. Genetic correlations between visual scores of fat and both tissue proportions and ratios were generally high (around 0·65). These results suggest that fat scores collected on crossbred animals could be valuable in purebred selection programmes where improving carcass composition of the crossbred generation is the underlying objective.

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Genetic parameters of body weight in japanese quails (Coturnix japonica Temminck & Schlegel, 1849) in the Philippines

Annals of Tropical Research ◽

10.32945/atr4216.2020 ◽

2020 ◽

pp. 72-78

Author(s):

Angie Poliquit

Keyword(s):

Body Weight ◽

Genetic Parameters ◽

Additive Genetic Variance ◽

Genetic Correlations ◽

The Philippines ◽

Japanese Quails ◽

Randomized Design ◽

Body Weights ◽

Reproduction Traits ◽

Heritability Estimates

The establishment of breeding and selection programs to improve the genetic potential of poultry necessitates estimation of genetic parameters for different production and reproduction traits, Restricted maximum likelihood (REML) software was used to estimate the heritability (h2) and genetic correlations (r) of body weights in Japanese quails (C. japonica) from hatch to fifth week of age. A total of 224 Japanese quails composed of 56 males and 168 females arranged in a Completely Randomized Design (CRD) served as the base population. Body weight records, measured weekly from hatch to fifth week, were utilized to estimate the genetic parameters. Heritability estimates were 0.093±0.004, 0244±0.010, 0.031±0.001, 0082±0.004, 0325±0.016 and 0.025±0.001 for body weights at hatch (BW0), first week (BW1), second week (BW2), third week (BW3), fourth week (BW4) and fifth week (BW5), respectively. Low heritability estimates depict a decrease in additive genetic variance as the generations progressed. Negative genetic correlation was found between BW0 and BW4 (r=- 0.027). The significant positive genetic correlations of BW0 with BW1 (r=0.271); BW1 with BW2 (r=0.270), BW3 (r=0.294), BW4 (r=0.255), and BW5 (r=0.243); BW2 with BW3 (r=0.561), BW4 (r=0.649), and BW5 (r=0.503); BW3 with BW4 (r=0.726), and BW5 (r=0.551); and BW4 with BW5 (r=0.689) are expected to bring correlated responses in the other traits.

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Random regression models to estimate genetic parameters for test-day milk yield and composition in Iranian buffaloes

Archives Animal Breeding ◽

10.7482/0003-9438-56-027 ◽

2013 ◽

Vol 56 (1) ◽

pp. 276-284 ◽

Cited By ~ 1

Author(s):

M. Madad ◽

N. Ghavi Hossein-Zadeh ◽

A. A. Shadparvar ◽

D. Kianzad

Keyword(s):

Milk Yield ◽

Milk Fat ◽

Milk Protein ◽

Genetic Parameters ◽

Genetic Correlations ◽

Random Regression ◽

Production Traits ◽

Environmental Correlations ◽

Protein Percentage ◽

Heritability Estimates

Abstract. The objective of this study was to estimate genetic parameters for milk yield and milk percentages of fat and protein in Iranian buffaloes. A total of 9,278 test-day production records obtained from 1,501 first lactation buffaloes on 414 herds in Iran between 1993 and 2009 were used for the analysis. Genetic parameters for productive traits were estimated using random regression test-day models. Regression curves were modeled using Legendre polynomials (LPs). Heritability estimates were low to moderate for milk production traits and ranged from 0.09 to 0.33 for milk yield, 0.01 to 0.27 for milk protein percentage and 0.03 to 0.24 for milk fat percentage, respectively. Genetic correlations ranged from −0.24 to 1 for milk yield between different days in milk over the lactation. Genetic correlations of milk yield at different days in milk were often higher than permanent environmental correlations. Genetic correlations for milk protein percentage ranged from −0.89 to 1 between different days in milk. Also, genetic correlations for milk percentage of fat ranged from −0.60 to 1 between different days in milk. The highest estimates of genetic and permanent environmental correlations for milk traits were observed at adjacent test-days. Ignoring heritability estimates for milk yield and milk protein percentage in the first and final days of lactation, these estimates were higher in the 120 days of lactation. Test-day milk yield heritability estimates were moderate in the course of the lactation, suggesting that this trait could be applied as selection criteria in Iranian milking buffaloes.

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Genetic parameters of milk cholesterol content in Holstein cattle

Canadian Journal of Animal Science ◽

10.1139/cjas-2018-0010 ◽

2018 ◽

Vol 98 (4) ◽

pp. 714-722 ◽

Cited By ~ 4

Author(s):

Duy N. Do ◽

Allison Fleming ◽

Flavio S. Schenkel ◽

Filippo Miglior ◽

Xin Zhao ◽

...

Keyword(s):

Milk Fat ◽

Genetic Parameters ◽

Genetic Correlations ◽

Cholesterol Content ◽

Production Traits ◽

Fat Percentage ◽

Bivariate Models ◽

Estimate Heritability ◽

Fat Yield ◽

Using Data

This study aimed to estimate heritability for milk cholesterol (CHL) and genetic correlations between milk CHL and other production traits (test-day milk, fat, and protein yields, fat and protein percentages, and somatic cell score). Milk CHL content was determined by gas chromatography and expressed as mg of CHL in 100 g of fat (CHL_fat) or in 100 mg of milk (CHL_milk). Univariate models were used to estimate variances and heritability, whereas bivariate models were used to compute correlations using data from 1793 cows. The average concentrations (standard deviation) of CHL_fat and CHL_milk were 275.63 (75) mg and 11.16 (3.63) mg, respectively. Milk CHL content was significantly affected by days in milk and herd (P < 0.05), but not by parity, regardless of the scale of expression. Heritability estimates for CHL_fat and CHL_milk were 0.06 ± 0.04 and 0.17 ± 0.06, respectively. Phenotypic and genetic correlations between CHL_fat and CHL_milk were 0.82 and 0.44 ± 0.24, respectively. CHL_fat had nonsignificant genetic correlations with all production traits, whereas CHL_milk had significant (P < 0.05) genetic correlations with milk yield (−0.47), fat yield (0.51), protein percentage (0.56), and fat percentage (0.88). This is the first study to estimate genetic parameters for milk CHL content. Further studies are required to assess the possibility of genetically selecting cows with lower milk CHL content.

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