Genetic Analysis of Ultrasound and Carcass Measurement Traits in a Regional Hanwoo Steer Population

Abstract

Ultrasound measurements of backfat thickness (UBF), longissimus muscle area (ULMA) and marbling score (UMS) and carcass measurements of carcass weight (CW), backfat thickness (BF), longissimus muscle area (LMA), and marbling score (MS) on 7,044 Hanwoo steers were analyzed to estimate genetic parameters. Data from Hanwoo steers that were raised, finished in Hoengseong-gun, Gangwon-do (province) and shipped to slaughter houses during the period from October 2010 to April 2013 were evaluated. Ultrasound measurements were taken at approximately three months before slaughter by an experienced operator using a B-mode real-time ultrasound device (HS-2000, FHK Co. Ltd., Tokyo, Japan) with a 3.5 MHz linear probe. Ultrasound scanning was on the left side between 13th rib and the first lumbar vertebrae. All slaughtering processes and carcass evaluations were performed in accordance with the guidelines of beef grading system of Korea. To estimate genetic parameters, multiple trait animal models were applied. Fixed effects included in the models were: the effects of farm, contemporary group effects (year-season at the time of ultrasound scanning in the models for UBF, ULMA, and UMS, and year-season at slaughter in the models for CW, BF, LMA, and MS), the effects of ultrasound technicians as class variables and the effects of the age in days at ultrasound scanning or at slaughtering as linear covariates, respectively for ultrasound and carcass measures. Heritability estimates obtained from our analyses were 0.37 for UBF, 0.13 for ULMA, 0.27 for UMS, 0.44 for CW, 0.33 for BF, 0.36 for LMA and 0.54 MS, respectively. Genetic correlations were strongly positive between corresponding traits of ultrasound and carcass measures. Genetic correlation coefficient between UBF and BF estimate was 0.938, between ULMA and LMA was 0.767 and between UMS and MS was 0.925. These results suggest that ultrasound measurement traits are genetically similar to carcass measurement traits.

Estimation of Genetic Parameters and Correlation between Yearling Ultrasound Measurements and Carcass Traits in Hanwoo Cattle

“…The estimated heritability of the eight analyzed traits were moderate to high, ranging from 0.19 to 0.59 ( Table 2 ), indicating considerable additive genetic variation in most of the traits. The estimates of posterior heritability for the carcass traits were 0.56 (BFT), 0.42 (CW), 0.50 (EMA), and 0.59 (MS), which were comparable to those previously reported in Hanwoo cattle [ 15 , 17 , 18 , 19 , 20 , 21 , 22 ]. Our heritability estimate of 0.31 for YW was similar to the estimates of 0.26 and 0.30 obtained by Mehrban et al [ 21 ] and Park et al [ 15 ], respectively, but was higher than the estimate of 0.18 obtained by Choi et al [ 19 ] in Hanwoo beef cattle.…”

A Gene-Set Enrichment and Protein–Protein Interaction Network-Based GWAS with Regulatory SNPs Identifies Candidate Genes and Pathways Associated with Carcass Traits in Hanwoo Cattle

“…Kim et al [51] had also reported a medium negative correlation between EMA and BFT. The genetic and phenotypic correlation estimated between MS and EMA was higher than what was reported previously by Roh et al and Son et al [48,56] but consistent with the estimates of Hwang et al [49]. These results suggest that a selection based on CWT will have a low to medium improvement in BFT, EMA, and MS, while a selection based on BFT or MS will have minimal improvement on BFT.…”

“…The carcass traits of the sample were normally distributed ( Table 1). The mean values of CWT, BFT, EMA, and MS measured at a similar slaughter age were consistent with those of Roh et al [48] but differed marginally with [49]. Several previous studies have reported lower estimates for these traits [29,50], which could be attributed to differences in the number of animals investigated or nutritional status during finishing period or due to differences in the methods employed for measuring the phenotypes.…”

Genetic parameters and correlations of related feed efficiency, growth, and carcass traits in Hanwoo beef cattle

“…and BT were very low and positive (0.18), which is corroborated by the results of earlier studies (0.17 [24]; 0.16 [11]; 0.17 [32]), but was considerably lower than the estimate of 0.40 reported by Hwang et al [33] [12,19,20,28]. However, a negative genetic correlation was observed between MS and EMA (−0.40) in an earlier study in Hanwoo cattle [11].…”