• 한국동물위생학회지
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• 제34권2호
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• pp.179-185
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• 2011

Neospora caninum is now recognized as one of the important causes of abortion in cattle worldwide, but there was no report on seroprevalence of antibodies to N. caninum in cattle at Seoul slaughtering center. Serum samples from 610 Korean indigenous cattle (Hanwoo) and 246 Holstein cattle from 452 farms located all over the country, Korea, were tested for N. caninum antibodies using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Seven of 610 (1.1%) Hanwoo and 54 of 246 (22.0%) Holstein cattle were seropositive.

• 한국축산식품학회지
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• 제32권6호
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• pp.776-782
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• 2012

Marbling (intramuscular fat) is the most economically important meat quality trait in Hanwoo (Korean cattle). The endothelial differentiation G-protein coupled receptor 1 (EDG1) gene, involved in blood vessel formation, is located within the genomic region of a quantitative trait locus (QTL) for marbling on bovine chromosome 3. Thus, the EDG1 gene can be considered as a positional and functional candidate gene for meat quality in beef cattle. This study aimed to identify single nucleotide polymorphisms (SNPs) in the EDG1 gene and to evaluate their associations with carcass traits in Hanwoo population. We have sequenced a fragment of 5'-UTR of the EDG1 gene and identified one SNP. Genotyping of the g.166A>G SNP marker was carried out using PCR-RFLP analysis in 309 Hanwoo steers in order to evaluate their association with carcass traits. The g.166A>G SNP marker showed a significant effect on the marbling score. Animals with the GG genotype had higher marbling score compared with AA and AG genotypes (p<0.05). This SNP marker also showed a significant additive effects for the marbling score (p<0.05). These results suggest that the EDG1 gene can be used as a molecular marker for DNA marker-assisted selection in order to increase the levels of the marbling score in Hanwoo.

• 농업과학연구
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• 제46권2호
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• pp.395-404
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• 2019

This paper investigated the changes in Hanwoo breeding farms and herds according to their farm size and farm types based on traceability data in the Hanwoo industry. The major results are summarized as follows. First, the notion that small sized farms are breeding farms and middle or large sized farms are fattening farms is wrong. The results show that middle or large farms are not only fattening cattle but also breeding female cattle. Based on cattle data for over 6 months and under the criteria of a female cow ratio of 10 and 90% using the 2/4 quarter of 2018, the results show that the ratio of fattening only farms is 5.7%, that of breeding only farms is 59.0%, and that of fattening and breeding farms is 36.1%. The ratios of fattening, breeding, and both are 13.3, 13.5, and 73.2%, respectively, for a farm size with over 100 cattle. Second, this study found that the ratio of breeding farms over total farms has been increasing continuously over the last 5 years. This trend is apparent in the middle or large sized farms. However, the birth rate of cows is relatively lower in the middle and large sized farms than in the small sized farms. Hence, we can infer that the demand for a detection system for standing estrus in female cattle will increase. Additionally, the government should prepare relevant policies to stabilize the managerial conditions of middle or large sized farms.

• Asian-Australasian Journal of Animal Sciences
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• 제17권9호
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• pp.1241-1245
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• 2004

Two separate trials were conducted to determine effects of dietary level of whole flaxseed (WFS; 0, 10 and 15%) on feed intake, weight gain, and carcass yield and quality of Korean Hanwoo cattle. The daily gains of bulls (Trial 1) were not different among treatment groups, but those of cows (Trial 2) fed WFS 15% were higher (p<0.01) than others. Feed intake of both bulls and cows tended to decrease as dietary level of WFS increased. However, feed conversion ratio (feed/gain) of bulls tended to be improved by dietary inclusion of WFS and was significantly improved (p<0.01) in cows by increasing level of WFS. Neither carcass weight nor dressing percentage were affected by WFS level. Back fat thickness of bulls was decreased (p<0.01) by dietary inclusion of WFS and the same trend was observed in cows without statistical significance. Loin-eye area of bulls was not different among treatment groups but was significantly higher (p<0.01) in cows fed WFS. Carcass yield and quality were not improved by WFS addition. The results indicate that WFS is an acceptable fat source in diets of finishing beef cattle to increase energy density without any adverse effects.

• 현장농수산연구지
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• 제18권1호
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• pp.3-12
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• 2016

Vitamin D plays a vital role in maintaining blood concentrations of Ca and P. In lipid metabolism, vitamin D is also known to negatively affect the development of adipocytes, but it has received little attention with regard to improve marbling score in beef cattle via restricting its supply. Recently, the method of feeding fat soluble vitamins(including vitamin D)-deficient diets in Korean native cattle (Hanwoo) has been spread by feed companies and TMR plants. But proper guidelines in feeding vitamin D-deficient diets should be provided, otherwise it can adversely affect the health of cattle. To maximize marbling score, a controlled level of vitamin D in blood needs to be maintained and the proper period for feeding vitamin D-deficient diets should be provided. This review was conducted to highlight the regulatory effects of vitamins D on adipocyte differentiation, and provide information on improving beef quality grades in relation to feeding vitamin D-deficient diets in beef cattle.

• BMB Reports
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• 제49권9호
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• pp.514-519
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• 2016

Korean cattle (Hanwoo) are categorized into three breeds based on color: brown, brindle, and black. Among these breeds, brown Hanwoo has been subjected to intensive selection to improve meat traits. To identify genetic traces driven by recent selection in brown Hanwoo, we scanned the genomes of brown and brindle Hanwoo using a bovine SNP chip. We identified 17 candidate selection signatures in brown Hanwoo and sequenced four candidate regions from 10 individuals each of brown and brindle Hanwoo. In particular, non-synonymous SNPs in the ADSL gene (K88M, L189H, and R302Q) might have had mutational effects on protein structure as a result of altering the purine pathway during nucleotide breakdown. The ADSL gene was previously reported to affect meat quality and yield in livestock. Meat quality and yield are main breeding goals for brown Hanwoo, and our results support a potential causal influence of non-synonymous SNPs in the ADSL gene.

• Asian-Australasian Journal of Animal Sciences
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• 제21권1호
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• pp.25-28
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• 2008

In order to distinguish Korean cattle (Hanwoo) beef from the imported beef from Australia in Korean markets, DNA markers based on PCR-RFLP from mitochondrial genes and SRY gene were applied. A total of 2,826 beef samples comprising 1,495 Hanwoo and 1,331 foreign cattle breeds were obtained in Korea. An 801 bp fragment of the SRY gene on the bovine Y chromosome, a 343 bp fragment of ND4 gene and a 528 bp fragment of ND5 gene in the bovine mtDNA were amplified by PCR and digested with three restriction enzymes, MseI, HpyCH4III and Tsp509I, respectively. The results showed that Bos taurus (T) type was the majority in Hanwoo by combining three markers (99.5%). However, 78.2% of Bos indicus (I) type was observed in the imported beef samples. These results indicated that three markers used in this study will be used as valuable markers for discriminating imported beef against Hanwoo.

• 한국동물위생학회지
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• 제42권2호
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• pp.61-65
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• 2019

Seroprevalence of Coxiella burnetii (Q fever) in bulk-tank milk and cattle in Daegu area was analyzed from 2017 to 2018 by ELISA. The prevalence of antibodies in collected bulk-tank milk from 12 dairy cattle farms was 41.7% (10/24) and the seroprevalence of 249 cows reared in the area of Daegu was 3.2% (8/249) By age, the seroprevalence was 1.9% (2/105) in less than 2 years of age, 4.2% (5/119) between 3 and 5 years of age and 4.0% (1/25) in more than 6 years of age. By breed, the seroprevalence of the Hanwoo cattle was 1.2% (2/162) and the seroprevalence of the dairy cattle was 6.9% (6/87). The result suggested that seroprevalence of C. burnetii was relatively high in both bulk-tank milk samples and dairy cattle than the Hanwoo cattle. Based on these data, it is necessary to keep monitoring the prevalence of Q fever in Daegu area.

• 농업과학연구
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• 제48권3호
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• pp.527-534
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• 2021

This study investigated the possibility of performing selection using 30-month carcass traits by estimating the genetic parameters of 24- and 30-month carcass traits. Data used in this study were the carcass traits of 13,151 heads slaughter at the age of 24 and 30 months. As a result of the study, the heritability of backfat thickness, carcass weight, eye muscle area and marbling score at 24 months of age were estimated to be 0.588, 0.354, 0.467 and 0.587, respectively. The heritability of backfat thickness, carcass weight, eye muscle area and marbling score at 30 months of age were estimated to be 0.498, 0.577, 0.505 and 0.530, respectively. The ranking correlation was 0.516 between the carcass selection indices of 24 and 30 months of age. By providing a 30-month selection index, it is possible to use semen suitable for farm profits, and more semen information can be provided to farms than previously. Furthermore, studies on a selection index based on 30-month carcass traits are needed to provide highly accurate information.

• Asian-Australasian Journal of Animal Sciences
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• 제24권6호
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• pp.744-751
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• 2011

Meat production and quality traits in beef cattle are largely affected by genetic factors. Acetyl-Coenzyme A carboxylase-${\alpha}$ (ACACA) plays a key role in the regulation and metabolism of fatty acid biosynthesis in mammalian animals. The gene encoding ACACA enzyme was chosen as a candidate gene for carcass and meat traits. In this study, we investigated effects of single nucleotide polymorphisms (SNPs) in the ACACA gene on beef carcass and meat traits in Hanwoo (Korean cattle) populations. We have sequenced a fragment of intron I region of the Hanwoo ACACA gene and identified two SNPs. Genotyping of the two SNP markers (g.2344T>C and g.2447C>A) was carried out using PCR-SSCP analysis in 309 Hanwoo steers to evaluate their association with carcass and meat production traits. The g.2344C SNP marker showed a significant increasing effect on LW (p = 0.009) and CW (p = 0.017). Animals with the CC genotype had higher CW and LW compared with TT and TC genotypes (p<0.05). The g.2447A SNP marker was associated with higher MC (p = 0.019). Animals with the AA genotype had higher MC than animals with CC and CA genotypes (p<0.05). Although the degree of linkage disequilibrium (LD) was not strong between g.2344T>C and g.2447C>A in the LD analysis, four major haplotype classes were formed with two SNP information within the ACACA gene. We constructed haplotypes using the HaploView software package program and analyzed association between haplotypes and carcass traits. The haplotype of ACACA gene significantly affected the LW (p = 0.027), CW (p = 0.041) and MC (p = 0.036). The effect of h1 haplotype on LW and CW was larger than that of h3 haplotype. Animals with the h1 haplotype also had greater MC than did animals with h2 haplotype. Consequently, the ACACA gene could be useful as a DNA marker for meat production traits such as carcass yield and meat contents in Hanwoo.