• Animal Bioscience
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• v.37 no.4
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• pp.555-566
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• 2024

Objective: This study aimed to assess the genetic parameters and accuracy of genomic predictions for twenty-four linear body conformation traits and overall conformation scores in Korean Holstein dairy cows. Methods: A dataset of 2,206 Korean Holsteins was collected, and genotyping was performed using the Illumina Bovine 50K single nucleotide polymorphism (SNP) chip. The traits investigated included body traits (stature, height at front end, chest width, body depth, angularity, body condition score, and locomotion), rump traits (rump angle, rump width, and loin strength), feet and leg traits (rear leg set, rear leg rear view, foot angle, heel depth, and bone quality), udder traits (udder depth, udder texture, udder support, fore udder attachment, front teat placement, front teat length, rear udder height, rear udder width, and rear teat placement), and overall conformation score. Accuracy of genomic predictions was assessed using the single-trait animal model genomic best linear unbiased prediction method implemented in the ASReml-SA v4.2 software. Results: Heritability estimates ranged from 0.10 to 0.50 for body traits, 0.21 to 0.35 for rump traits, 0.13 to 0.29 for feet and leg traits, and 0.05 to 0.46 for udder traits. Rump traits exhibited the highest average heritability (0.29), while feet and leg traits had the lowest estimates (0.21). Accuracy of genomic predictions varied among the twenty-four linear body conformation traits, ranging from 0.26 to 0.49. The heritability and prediction accuracy of genomic estimated breeding value (GEBV) for the overall conformation score were 0.45 and 0.46, respectively. The GEBVs for body conformation traits in Korean Holstein cows had low accuracy, falling below the 50% threshold. Conclusion: The limited response to selection for body conformation traits in Korean Holsteins may be attributed to both the low heritability of these traits and the lower accuracy estimates for GEBVs. Further research is needed to enhance the accuracy of GEBVs and improve the selection response for these traits.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.3
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• pp.167-176
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• 2020

The objective of the present study was to determine the best model to describe and quantify the changes in live body weight, height at withers, height at rump, body length and chest girth of Holstein cows raised under Korean feeding conditions for 50 months. The five standard growth models namely polynomial linear regression models, regression of growth variables on the first and second-order of ages in days (model 1) and regression of growth variables on age covariates from first to the third-order (model 2) as well as non-linear models were fitted and evaluated for representing growth pattern of Holstein cows raised in Korean feeding circumstances. Nonlinear models fitted were three exponential growth curve models; Brody, Gompertz, and von Bertalanffy functional models. For this purpose, a total of 22 Holstein cows raised in Korea used in the period from April 2016 to May 2020. Each model fitted to monthly growth curve records of dairy cows by using PROC NLIN procedure in SAS program. On the basis of the results, nonlinear models showed the lower root mean square of error (RMSE) for live body weight, height at withers, height at rump, body length and chest girth (12.22, 1.95, 1.55, 4.04, 2.06) with higher correlation coefficiency (R²) values for live body weight, height at withers, height at rump, body length and chest girth (0.99, 0.99, 0.99, 1.00, 1.00). Overall, the evaluation of the different growth models indicated that the Gompertz model used in the study seemed to be the most appropriate one for standard growth of Holstein cows raised under Korean feeding system.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.322-329
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• 2011

A whole genome association (WGA) study was conducted to identify quantitative trait loci (QTL) for body conformation traits in Hanwoo cattle. The phenotypes of 497 steers were recorded from the Hanwoo Improvement Center of National Agricultural Cooperative Federation, Seosan, Korea, and analyzed using the Illumina Bovine 50 k SNP chip. A set of 35,987 SNPs that were available in the Hanwoo population was selected from the chip. After adjustments for the effects of year-season of birth, region and sire, phenotypes were regressed on each SNP using a linear regression model. Three hundred nineteen SNPs were detected for the ten conformation traits (p<0.003). For the significant SNPs, stepwise regression procedures were applied to determine best sets of markers. A total of 72 SNPs were selected (p<0.001), for which the sets of 5, 9, 10, 9, 8, 11, 4, 6, 3 and 7 SNPs were determined for height at withers, rump height, body length, chest depth, chest width, rump length, hip width, thurl width, pinbone width and heart girth, respectively. About 7-26% of the total phenotypic variation was explained by the set of SNPs for each trait. QTL for the conformation traits were harbored on most bovine chromosomes (BTAs). Four SNPs with pleiotropic effects on height at withers and rump height were detected on BTAs 3, 4, 6 and 16. A SNP with pleiotropic effects on chest width and rump length was also detected on BTA10. Two QTL regions, i.e. between 87 and 97 Mb in BTA3 and between 41 and 44 Mb in BTA7, were found, in which SNPs were detected for the five and three conformation traits, respectively. The detected SNPs need to be validated in other Hanwoo populations for commercial application to the genetic improvement of conformation characteristics in Hanwoo via marker-assisted selection (MAS).

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1527-1530
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• 2002

Factor analysis was applied to the phenotypic correlation matrix of 15 linear type traits (scored linearly 1 to 50 points) for 2035 Holstein cows of 38 sires computed from data collected between 1988 and 1992 in Beijing Shuangqiao Farm and Beijing Xijiao Farm. The 15 linear type traits were stature, body strength, body depth, dairy form, rump angle, rump length, rump width, rear leg side view, foot angle, fore udder attachment, rear udder height, rear udder width, udder cleft, udder depth and teat placement rear view. The first four components accounted for 49.1% of the total variance in type scores. Factor 1 reflected strong cows, with deep bodies, with long and wide rumps, and tall in stature. Factor 2 reflected cows with well attached fore udders, wide rear udders and whose udders were supported by strong suspensory ligaments with close teat placement. Factor 3 reflected cows with good dairyness, sickled in the hocks, high rear udders and udder floors above the hocks. Factor 4 reflected cows with sloping rumps from hooks to pins and with steep foot angle. Principal component and factor analyses are useful to clarify the relationships among type traits.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.23-32
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• 2003

Genetic parameters for growth and carcass traits were estimated on the basis of the data from 3,415 heads of Hanwoo bulls tested at Livestock Improvement Main Center. The data were divided into two groups : the first period group consisted of 1,592 heads of bulls tested in individual pens from 1986 to 1990 and the second period group consisted of 1,823 heads of bulls tested in group pens from 1991 to 1996. The testing period was from 6 to 18 months of age in the first period group and 10 to 22 months of age in the second period group. The average daily gains during 6 to 12 months and 12 to 18 months were 1.01kg and 0.77kg, respectively, in the first period group and 0.80kg and 0.95kg in the second period group, and the compensated growth appeared to have occurred in the second period group. The heritability of body weight at 12 months estimated was 0.37 during the first period and 0.47 during the second period. The heritability of body weight at 18 months was 0.29 during the first period and 0.33 during the second period. The heritability of average daily gain during 6${\sim}$12 months estimated was 0.26 for the first period and 0.33 for the second period. The heritability of average daily gain during 12${\sim}$18 months estimated was 0.11 for the first period and 0.22 for the second period. The heritabilities of body weights and average daily gains estimated tended to be higher in the second period than in the first period. The heritability of body measurements at 12 months during the first period estimated was 0.30 for withers height, 0.25 for rump height, 0.11 for thurls width and 0.13 for chest girth. The heritability of body measurments at 12 months during the second period was 0.53 for withers height, 0.44 for rump height, 0.36 for thurls width and 0.56 for chest girth. The heritabilites of withers height, rump height, thurls width and chest girth at 18 months of age were 0.40, 0.22, 0.12 and 0.21 during the first period and 0.45, 0.42, 0.42 and 0.35 during the second period, respectively. The heritability of carcass traits estimated during the first period was 0.11 for carcass weight, 0.24 for dressing percent, 0.25 for eye muscle area, 0.18 for backfat thickness and 0.21 for carcass length. The heritabilities of carcass weight, dressing percent, eye muscle area, backfat thickness, carcass length and marbling score during the second period estimated were 0.32, 0.52, 0.33, 0.51, 0.58 and 0.31, respectively. The genetic correlations between the first and second periods estimated were higher than 0.8 for chest girth at 12 months, rump height at 18 months, carcass weight and dressing percent, but were lower for other traits.

• Animal Bioscience
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• v.34 no.4
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• pp.516-524
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• 2021

Objective: The genetic evaluation of Santa Inês sheep was performed for resistance to gastrointestinal nematode infection (RGNI) and body size using different relationship matrices to assess the efficiency of including genomic information in the analyses. Methods: There were 1,637 animals in the pedigree and 500, 980, and 980 records of RGNI, thoracic depth (TD), and rump height (RH), respectively. The genomic data consisted of 42,748 SNPs and 388 samples genotyped with the OvineSNP50 BeadChip. The (co)variance components were estimated in single- and multi-trait analyses using the numerator relationship matrix (A) and the hybrid matrix H, which blends A with the genomic relationship matrix (G). The BLUP and single-step genomic BLUP methods were used. The accuracies of estimated breeding values and Spearman rank correlation were also used to assess the feasibility of incorporating genomic information in the analyses. Results: The heritability estimates ranged from 0.11±0.07, for TD (in single-trait analysis using the A matrix), to 0.38±0.08, for RH (using the H matrix in multi-trait analysis). The estimates of genetic correlation ranged from -0.65±0.31 to 0.59±0.19, using A, and from -0.42±0.30 to 0.57±0.16 using H. The gains in accuracy of estimated breeding values ranged from 2.22% to 75.00% with the inclusion of genomic information in the analyses. Conclusion: The inclusion of genomic information will benefit the direct selection for the traits in this study, especially RGNI and TD. More information is necessary to improve the understanding on the genetic relationship between resistance to nematode infection and body size in Santa Inês sheep. The genetic evaluation for the evaluated traits was more efficient when genomic information was included in the analyses.

• Journal of Animal Science and Technology
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• v.52 no.6
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• pp.467-473
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• 2010

A total of 4,323,781 records for informal 16 primary linear descriptive traits of dairy cows in Holstein breed from 1988 to 2007 in USA were analyzed to estimate adjustment factors for lactation number and stage. While all factors in the model were highly significant (P < 0.01), major influences on linear type traits were due to lactation number and stage. The frequencies of lactation number 1 through 6 were 58.6, 22.0, 11.8, 4.8, 2.1, and 0.8%, respectively. Further, the frequencies of lactation stage were 0.7, 76.9, 15.3, 4.9, and 2.1%, respectively, for springing, early, medium, late, and dry. To adjust 16 linear traits (stature, dairy form, strength, body depth, rump width, rump angle, legs rear view, leg set, foot angle, fore udder, rear udder height, rear udder width, udder support, udder depth, and front teat placement), additive and multiplicative adjustment factors of lactation number (lactations 2 to 4) and stage (springing, medium, late and dry) were estimated with the solutions in the generalized linear model, assigning lactation 1 and stage early as base class. Additive adjustment factors of lactation number ranged from -1.23 to 2.908, while multiplicative factors ranged from 0.853 to 2.207. Further, additive and multiplicative adjustment factors for lactation stage ranged from -0.668 to 0.785, and from 0.891 to 1.154. Application of adjustment factors to 20 randomly sampled sub-data sets produced the results that additive adjustment factors for both lactation number and stage reduced more mean square of lactation number and stage over 16 linear traits than any combination of adjustments, and leaded additive adjustment factors for both lactation number and stage as a choice of methods for adjustment of informal 16 primary linear type traits collected by classifiers of AI studs.

• Journal of Animal Science and Technology
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• v.44 no.6
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• pp.643-652
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• 2002

Data were consisted of the ten body measurements (withers height, rump height, body length, chest depth, chest width, rump width, rump length, thurls width, hipbone width and chest girth) of 642 steers (Korean cattle), which was entered in the National Beef Quality Contest hosted by the Korea Animal Improvement Association from 1997 to 2001. A principal components analysis was used to classify the body types of the steers, and estimate the correlations between carcass traits and principal components for the body measurements of the first, second, third and fourth period, respectively. The first principal component of body measurements at the first, second, third and fourth period accounted for 76.0%, 83.0%, 72.7% and 57.4% of the total variance, respectively. The sum of first, second and third principal component at each period accounted for 86.69%, 90.49%, 84.62% and 77.26% of the total variance, respectively. At each period, all the first principal component of the body measurements were positive and it generally showed large framed body shape. The size of body was influenced mostly by chest depth(0.328${\sim}$0.339) and rump length(0.325${\sim}$0.341). The second, third and fourth principal component at the each period were various. There were positive correlations between principal components index of each period and carcass traits such as carcass weight(0.539${\sim}$0.755), average daily gain(0.256${\sim}$0.564), backfat thickness(0.227${\sim}$0.280), and eye muscle area(0.187${\sim}$0.344). The correlation with yield grade index(－0.246${\sim}$－0.110), however, was negative. The correlation with marbling score(0.066${\sim}$0.099) was low or statistically insignificant. According to principal component indexes of the second, third, and fourth components, the correlations with the carcass traits were various. There were no large differences between the correlations of the single body measurement trait with the carcass traits and the correlations of the first principal component indexes with the carcass traits.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.123-131
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• 2012

This study was conducted to estimate correlation structure between Hanwoo steer growth traits - body weights at 6 month, 12 month, 18 month and 24 month of age, average daily gain, carcass traits, body size traits at 18 months of age. Hanwoo progeny test data(body weight, body size traits) collected from 2004 to 2008 on a total of 1,838 steers at Hanwoo Improvement Main Center(NACF) were analyzed. Carcass traits were used to score the 24 months of age and slaughter. Correlation analyses were performed with observed scales of the traits and with residuals considering fixed effects in generalized linear models. The correlated coefficient estimated between live weight at slaughter(24 months of age) and cold carcass weight was high at 0.92. Correlation between beef yield index values and backfat thickness was estimated to be high and negative at -0.92. Hip height and wither height was found to be highly correlated(0.89). Chest width and chest depth also was found to be highly correlated at 0.73. Rump width was highly correlated with chest depth(0.75) and chest width(0.74). Correlation between pelvic width and rump width was estimated to be 0.74. Hipbone width was shown to be highly correlated with chest depth(0.73), chest width(0.70), rump width(0.75), or pelvic width(0.75). Correlation between wither height and carcass weight was 0.48 in observed scale. Chest girth was phenotyically (residual correlation) correlated with carcass weight (0.51), the estimates of which were some higher than than with the other carcass traits. This study will be utilized for Hanwoo Steers genetic evaluation.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.9
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• pp.1250-1253
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• 2014

The objective of this study was to estimate the parameters of Gompertz growth curves with the measurements of body conformation, real-time ultrasound longissimus dorsi muscle area (LMA) and backfat thickness (BFT) in Hanwoo cows. The Hanwoo cows (n = 3,373) were born in 97 Hanwoo commercial farms in the 17 cities or counties of Gyeongbuk province, Korea, between 2000 and 2007. A total of 5,504 ultrasound measurements were collected for the cows at the age of 13 to 165 months in 2007 and 2008. Wither height (HW), rump height (HR), the horizontal distance between the top of the hips (WH), and girth of chest (GC) were also measured. Analysis of variance was conducted to investigate variables affecting LMA and BFT. The effect of farm nested in location was included in the statistical model, as well as the effects of HW, HR, WH, and GC as covariates. All of the effects were significant in the analysis of variance for LMA and BFT (p<0.01), except for the HR effect for LMA. The two ultrasound measures and the four body conformation traits were fitted to a Gompertz growth curve function to estimate parameters. Upper asymptotic weights were estimated as $54.0cm^2$, 7.67 mm, 125.6 cm, 126.4 cm, 29.3 cm, and 184.1 cm, for LMA, BFT, HW, HR, WH, and GC, respectively. Results of ultrasound measurements showed that Hanwoo cows had smaller LMA and greater BFT than other western cattle breeds, suggesting that care must be taken to select for thick BFT rather than an increase of only beef yield. More ultrasound records per cow are needed to get accurate estimates of growth curve, which, thus, helps producers select animals with high accuracy.