Effects of Geographic Locations and Year-Seasons of Birth on Ultrasound Scanned Measures and Carcass Traits of Hanwoo Steers

Abstract

Ultrasound measures of back fat thickness (UBF), eye muscle area (UEMA) and marbling score (UMS) and carcass measures of carcass weight (CW), backfat thickness (BF), eye muscle area (EMA) and marbling score (MS) were available on 26,129 Hanwoo steers. Statistically significant differences by regions of the farms location and birth years-seasons for the steers taken ultrasound measures and their carcass measures (p<0.01) were found. Steers in Gyeonggi province showed the highest values in ultrasound measures and carcass traits except in BF compared to steers in the other provinces. Comparing between ultrasound and carcass measures, UBF was thicker in general than BF in all regions except in Daejeon city. UEMA was higher than EMA in all regions except in Gyeonggior in Jeju provinces. Especially, the difference in Jeonnam province between UEMA and EMA was 7㎠ while the differences between UMS and MS ranged from 0.9 to 2.26 depending on the regions of steers located. Steers born in spring showed greater ultrasound or carcass values than those born in autumn. However, carcass measures of steers born in autumn were greater than those born in spring, 2009 except MS. The pearson and residual correlations were 0.63 and 0.65 between UBF and BF, 0.31 and 0.32 between UEMA and EMA and 0.56 and 0.56 between UMS and MS, respectively.

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

“…The similar age structure for ultrasound measures and carcass measures were found in the studies by Cheong et al (2012) or by Kim et al (2012). The averages of UBF, ULMA, UMS were 9.71 mm, 86.88 cm 2 , 4.14, respectively in the report of Cheong et al (2012), and 9.41 mm, 87.38 cm 2 , 5.16, respectively in the report of Kim et al (2012). The averages of CW, BF, LMA, and MS were 417.94 kg, 12.91 mm, 89.92 cm 2 , 5.31, respectively in the report of Cheong et al (2012), and 393.14 kg, 10.59 mm, 89.84 cm 2 , 5.93, respectively in the report of Kim et al (2012).…”

“…Therefore, we could consider that were no extra effects on carcass traits other than animal management effects and individual animals’ genetic effects that are normally accounted in genetic analysis models. The similar age structure for ultrasound measures and carcass measures were found in the studies by Cheong et al (2012) or by Kim et al (2012) . The averages of UBF, ULMA, UMS were 9.71 mm, 86.88 cm 2 , 4.14, respectively in the report of Cheong et al (2012) , and 9.41 mm, 87.38 cm 2 , 5.16, respectively in the report of Kim et al (2012) .…”

“…The averages of UBF, ULMA, UMS were 9.71 mm, 86.88 cm 2 , 4.14, respectively in the report of Cheong et al (2012) , and 9.41 mm, 87.38 cm 2 , 5.16, respectively in the report of Kim et al (2012) . The averages of CW, BF, LMA, and MS were 417.94 kg, 12.91 mm, 89.92 cm 2 , 5.31, respectively in the report of Cheong et al (2012) , and 393.14 kg, 10.59 mm, 89.84 cm 2 , 5.93, respectively in the report of Kim et al (2012) . The averages calculated in our study population were similar to those in the report of Cheong et al (2012) .…”

Estimation of Resonable Market Month of Age for Hanwoo Steer

“…To obtain a positive gross margin, Hanwoo should be slaughtered at around 28 months of age. 그리고 실제로 농가에서 출하한 거세우들의 도축일령을 보면 대 부분의 최근 연구들에서 평균 31개월 전후인 것으로 보고하고 있 는데 (Roh et al, 2010; Lee et al, 2011;Cheong et al, 2012) …”

Effects of weaning and castration ages on growth performance, blood metabolites, and carcass characteristics in Hanwoo steers

“…The optimal age of castration for Hanwoo calves is recommended before 8 months of age; however, many farms are conducting castration from 4 to 14 months of age. In Korea, the raising period for Hanwoo steers is over 31 months [ 4 , 16 , 28 ] with the delay of weaning and castration stated as one of the reasons for the increase in the raising period. Thus far, studies on age of weaning and castration have been conducted individually, and there have been no studies on the combined effects of weaning and castration ages on the growth performance and carcass grade in Hanwoo steers.…”