• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.270-284
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• 2021

The vomeronasal organ (VNO) is critical for reproduction and social behavior in ruminants, including cattle. The present study examined the structure of the VNO and its epithelial cells in neonatal and adult Korean native cattle (Hanwoo), Bos taurus coreanae, using immunohistochemistry and lectin histochemistry. Histologically, the VNO comprised two types of epithelia: medial vomeronasal sensory (VSE) and lateral vomeronasal non-sensory epithelia (VNSE). Numerous blood vessels and nerve bundles were observed within the vomeronasal cartilage encased lamina propria. Immunohistochemistry revealed high expression level of protein gene product9.5 and moderate expression level of olfactory marker protein in the neuroreceptor cells of the VSE and occasionally in some ciliated cells of the VNSE in both neonates and adults. The properties of the glycoconjugates in the VNO were investigated using 21 lectins, most of which were expressed at varied intensities in the VSE and VNSE, as well as in the lamina propria. Several lectins exhibited variations in their intensities and localization between neonatal and adult VNOs. This study is the first descriptive lectin histochemical examination of the VNO of Korean native cattle with a focus on lectin histochemistry, confirming that the VNO of Korean native cattle is differentiated during postnatal development.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.997-1006
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• 2003

This study was conducted to investigate the national methane emission from livestock enteric fermentation. For methane emission estimation, livestock were mainly categorized to cattle, swine, poultry, sheep, goats and horses, and cattle were further sub-categorized to calves, fattening cattle, breeding cows in Hanwoo and calves, fattening cattle and lactating cows in dairy cattle. Tier 2 methane emission factors were deduced based on the characteristics of animal performances, live weight, slaughter weight, daily weight gain, and feed digestibility in each category. Tier 2 emission factors of Hanwoo range from 39 to 49 kg/head/year and it is similar to that of Tier 1(47kg/head/year). Tier 2 emission factor of dairy cattle was 107 kg/head/year and it is slightly lower than that of Tier 1(118kg/head/year). Total methane emission from livestock enteric fermentation by Tier 2 method was estimated to be 126.8 tones in 2001. The methane emissions by Hanwoo, dairy cattle, swine, goats, horses and sheep were 61.70, 47.76, 13.08, 2.25, 0.17 and 0.01 tones, respectively. By the use of Tier 2 method instead of Tier 1, the accuracy and reliability of methane emission estimates from livestock enteric fermentation in Korea is considered to be improved.

• Journal of Animal Science and Technology
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• v.51 no.2
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• pp.123-128
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• 2009

Recently, the $2^{nd}$ generation genome map of the Korean cattle (Hanwoo) has been constructed by comparison of the nucleotide sequence of the Korean cattle BAC clones with whole genome sequence of the bovine data-base (B_tau 2.1 build). The objective of this study was to update the $2^{nd}$ generation genome map of the Korean cattle using the similar approach. The nucleotide sequence of the Korean cattle BAC clones utilized in the construction of the $2^{nd}$ generation map was compared with the newly released bovine data-base (B_tau 3.1 build) to generate the $3^{rd}$ generation map. While, 5,105 BAC clones were localized on bovine chromosome in the $2^{nd}$ generation map, a total of 9,595 BAC clones, which spans about 37.27% of the bovine chromosome after eliminating the overlapping sequence among the clones, have been mapped on the bovine chromosome in the $3^{rd}$ generation map. Further analysis of the nucleotide sequence of the BAC clones will allow us to develop map and facilitate to pinpoint the genes that are important for the improvement of the performance in this cattle breed.

• Journal of Life Science
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• v.19 no.3
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• pp.384-389
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• 2009

This study was carried out to elucidate the relation between expression levels of three melanin synthesis genes (Tyrosinase, Tyrosinase-related protein 1 and Dopachrome tautomerase) according to the Melanocortin-1 receptor genotypes with coat color patterns in Hanwoo cattle, Jeju black cattle and Holsteins. Using real-time semiquantitative reverse transcription-PCR assay (RT-PCR), the expression levels of these three genes were analyzed in skin tissues from four representative coat colored areas: yellowish-brown from MC1R e/e Hanwoo, wild type black from $E^+/E^+$ Jeju black cattle (JBC), and dominant black and white pied regions from $E^D/E^D$ Holstein. The TYR, TYRP1 and DCT genes showed higher expression levels of 4.5, 2.3 and 2.5 times higher in the black skin area of Holsteins than those of from JBC, respectively (p<0.001). In addition, the expression levels of these three genes from JBC were significantly higher than those from Hanwoo cattle (p<0.001). These results show that coat color phenotypes in Hanwoo cattle, JBC and Holsteins is directly correlated with TRY, TYRP1 and DCT transcription levels, which probably reflected involvement with MC1R genotypes; e/e in Hanwoo, $E^+/E^+$ in JBC and $E^D/E^D$ in Holsteins. Consequently, this study suggested that the status of MC1R protein may not only induce the transcription activities of a series of TYR and its related genes responsible for melanin synthesis, but also determine the levels of total melanin contents in bovine skin.

• Korean Journal of Organic Agriculture
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• v.21 no.2
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• pp.207-217
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• 2013

This study was conducted to estimate organic Hanwoo carrying capacity when whole crop wheat and triticale as winter forage crops were grown on different applying sources (no fertilizer, organic fertilizer or cattle slurry), and mixed sowing in combination with hairy vetch and forage pea at the level of 50% cattle slurry application during the period of 2009~2011. The experimental plots were consisted of 5 treatments. Each treatment was triplicates and allocated in the randomized complete block design. For whole crop wheat, annual mean dry matter (DM) yield was significantly (P<0.05) higher for fertilizer application treatments than for no fertilizer treatment, and crude protein (CP) yield was significantly (P<0.05) higher for forage pea and hairy vetch-mixed sowing treatments than for no fertilizer and organic ferilizer treatments. Mean CP, total digestible nutrients (TDN) and relative feed value (RFV) contents of legumes-mixed sowing treatments was significantly (P<0.05) higher than those of other treatments. As diets replaced with 70% whole crop wheat were provided for 450kg of Hanwoo heifers, legumes-mixed sowing treatments could raise more heifers than organic fertilizer and no fertilizer treatments. For triticale, annual mean DM, CP and TDN yields were significantly (P<0.05) higher for fertilizer application treatments than for no fertilizer treatment, and CP content of legumes-mixed sowing and cattle slurry application treatments was significantly (P<0.05) higher than that of other treatments. When 450kg of Hanwoo heifers were fed on diets replaced with 70% triticale, it was estimated that legumes-mixed sowing treatments at the level of 50% cattle slurry application could rear average 3.3~3.4 heads/ha/year, which was significantly (P<0.05) higher than no fertilizer treatment (2.5 heads/ha/year). It was indicated that DM yields of whole crop wheat and triticale were much more effective in cattle slurry application than organic fertilizer, and Legumes-mixed sowing at the level of 50% cattle slurry application rather than whole crop wheat or triticale alone increased yields per unit area and nutritional value such as CP content. In conclusion, it is conceived that whole crop wheat or triticale produced in the manner above can be used instead of grains imported as dietary protein sources in the organic Hanwoo feeding regimen.

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.79-85
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• 2013

The recent development in genetic assisted selection (combining traditional- and genome assisted selection method) and reproduction technologies will allow multiplying elite cow in Hanwoo small farm. This review describes the new context and corresponding needs for genome assisted selection schemes and how reproductive technologies can be incorporated to get more genetic gain for cow genetic improvement in Hanwoo. New improved massive phenotypes and pedigree information are being generated from commercial farm sector and these are allowing to do genetic evaluation using BLUP to get elite cows in Korea. Moreover cattle genome information can now be incorporated into breeding program. In this context, this review will discuss about combining the reproductive techniques (Multiple Ovulation Embryo Transfer; MOET) and genome assisted selection method to get more genetic gain in Hanwoo breeding program. Finally, how these technologies can be used for multiplication of elite cow in small farm was discussed.

• Journal of Embryo Transfer
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• v.23 no.3
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• pp.189-195
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• 2008

The objective of this study is to investigate the changes in concentrations of leptin and insulin in serum of Korean cattle (Hanwoo) with reproductive disorders and to examine the relationship among leptin, insulin, and body condition score (BCS). The concentration of leptin in serum of pregnant Hanwoo showed insignificant difference from that in serum of Hanwoo with reproductive disorder, such as repeat breeding, follicular cyst, corpus luteum cyst, ovarian atrophy, and feeble estrus (p>0.05). However, the concentrations of leptin and insulin in serum were changed with different BCS value. In emaciated Hanwoo (BCS $2.0\sim2.9$), they were significantly decreased compared to BCS $3.0\sim3.4$ (p<0.05). The leptin showed different genotypes with different BCS value. In BCS $2.0\sim2.9$, C/T genotype was expressed (83.3%) more than C/C (16.7%) or T/T (0%) genotype, whereas C/C genotype was expressed (62.5%) more than C/T (25.0%) or T/T (12.5%) genotype in BCS $3.5\sim4.0$. The insulin concentration in follicular fluid obtained from ovary with follicular cyst which has follicles having diameter of $25\sim40 mm$ was significantly higher (p<0.05) than those in normal follicle fluid which has follicles having diameter of $3\sim10 mm$. These results showed that concentration of leptin and insulin in serum were related to BCS value and follicular size and suggest that the changes in concentration of leptin and/or insulin in serum could be a potent biomarker for diagnosis of bovine reproductive disorder.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.722-730
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• 2016

The carcass traits and meat quality of Hanwoo (Korean native cattle) whose diets were supplemented with direct-fed microbial (DFM) and pine cone extract (PCE) were evaluated. Twenty head of Hanwoo steers were divided equally into four groups and for a period of 6 months were given different diets: One group was fed a basal diet as control (CON), the other three groups were fed a basal diet supplemented with DFM-1%, DFM+PCE-1% and DFM+PEC-3%, respectively. DFM+PCE3% diet resulted the lowest carcass quality grade. The loins of DFM-1% contained higher moisture and lower fat than did the loins from the CON group. The crude protein content of DFM+PCE-3% group was significantly higher than that of the other groups. The water holding capacity and Warner-Bratzler shear force of the DFM+PCE-1% and 3% groups were lower than those of the CON and DFM-1% groups. The DFM-1% and 3% groups contained lower saturated fatty acid, higher unsaturated fatty acid, mono-unsaturated fatty acid, and poly-unsaturated fatty acid than did CON and DFM+PCE 1% group. Moreover, the n6:n3 ratios of DFM-1% and DFM+PCE-1% and 3% groups were slightly lower than that of the CON group. Thus we concluded that DFM and PCE supplementation resulted healthier Hanwoo beef with lower fat content and n6:n3 ratio.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.463-473
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• 2018

The objective of this study was to investigate the effects of dietary hydrolysable tannin on growth performance and methane emissions of Hanwoo beef cows. Fifteen cows participated in a seven-week experiment. The cows were stratified by initial methane emissions and assigned to one of two treatments: Control and tannin supplementation. Commercial hydrolysable tannin was top-dressed to a concentrate mix at 3 g/kg based on the dry matter. Enteric methane production was measured for 4 consecutive days at 1 week before and 1, 3 and 7 weeks after the initiation of the experiment using a laser methane detector. The feed intake was measured daily during the methane measurement periods and an additional two days prior to each measurement. The body weight of the cows was measured every 4 weeks. Hydrolysable tannin had no effect (p > 0.05) on body weight, average daily gain, dry matter intake (DMI) and feed conversion ratio. After one week, the methane emission of the tannin supplementation group was 3.66 ppm-m / kg DMI, which was about 3.4% lower (p = 0.078) than that of the control group; however, this tendency disappeared at 3 weeks after the start of the experiment (p > 0.05). The results of this study show that hydrolysable tannin supplementation can reduce enteric methane emissions for a limited period in Hanwoo beef cows. More research, however, is needed to determine the optimal level of hydrolysable tannin supplementation to reduce enteric methane emissions for a longer period without adversely affecting the animal performance of Hanwoo beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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• pp.1791-1797
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• 2007

A study was conducted with 70 Hanwoo (Korean cattle) for genotyping bovine leukocyte antigen (BoLA)-DRB3.2 gene by using the polymerase chain reaction (PCR) and sequence based typing (SBT). Two-step PCR was carried out for amplifying a 284 bp fragment of the target gene and the PCR products were digested with three restriction enzymes namely RsaI, BstYI and HaeIII. Seventeen alleles were detected with frequencies ranging from 1.43 to 18.57% and one (x'aa) of these alleles was identified as a new allele that has not been reported before. The frequency of the new x'aa allele identified in this breed was 12.86%. In addition, the seven most frequently observed alleles (DRB3.2 *10, *15, *16, *26, *27, *54 and x'aa) accounted for 74.28% of the alleles in this population. The phylogenetic tree showed that the BoLA-DRB3.2 allele sequences of Hanwoo were shared with other Bos taurus breeds and no specific clade for Hanwoo was identified. It indicates high heterogeneity of the BoLA-DRB3 gene in this population and may give some ideas for breeding animals having better disease resistance.