Bos Taurus Coreanae Research Articles

Identification and analysis of phospholipid transfer protein polymorphisms and their association with marbling score in Hanwoo (Korean cattle)

Phospholipid transfer protein (PLTP) regulates high-density lipoprotein metabolism. The gene encoding PLTP is located on bovine chromosome 13. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the Hanwoo (Bos taurus coreanae) PLTP gene to detect novel mutations affecting economically important traits. Five SNPs were identified in the coding region (C7368T, G7453A, C9888T, and C9905T) and intron (A1750G). G7453A changes amino acid 362 of PLTP from alanine to threonine, and C9888T changes amino acid 491 of PLTP from proline to serine. Statistical analyses revealed that the G7453A and C9888T polymorphisms in the PLTP gene were significantly associated with marbling score (P < 0.05). The relationship between haplotype and economic traits was analyzed and found to be significantly associated with marbling score (P < 0.05). The results suggest that PLTP polymorphisms might be an important genetic influence on economic traits in Hanwoo.

Effect of Stocking Density on Eating Behavior of Finishing Hanwoo Steers (Bos taurus coreanae)

This study was carried out to investigate the effects of stocking density on eating and ruminating behavior of Hanwoo steers (Bos taurus coreanae) in the finishing period. A total of 30 finishing Hanwoo steers (631.3 ± 11.4 kg, 25 months old) were allocated to one of four stocking density groups comprising 1, 2, 3, and 4 steers per 32 m 2 pen [G1 (32 m 2 ), G2 (16 m 2 ), G3 (10.7 m 2 ) and G4 (8 m 2 ), respectively] in triplicate. Eating, rumination behaviors, as well as dry matter intake of steers were measured, and the results were subjected to analysis of variance with stocking density as the main effect. The results of eating behaviors over 48 hours are summarized as follows: Total intake was significantly (p G2 > G3 > G4 (p<0.01). However, resting time and chewing time (sum of eating and ruminating) were not significantly different among the treatments. Number of boluses and number of total chews were highest in G1 (p<0.01), whereas number of chews per bolus was highest in G3 (p<0.01). Ruminating time per bolus as well as number of boluses per minute was not significantly different among the treatments. Number of defecations was higher in G1 and G2 animals compared to G3 and G4 animals (p<0.01). However, stocking density had no effect on drinking or urination. In conclusion, increasing stocking density (i.e. G4) per pen decreased voluntary intake, ruminating time, and total chewing number in the finishing period of Hanwoo steers. However, care must be taken in discussing stocking density in the present study as the space allowance per animal was satisfactory to meet the current animal welfare regulation in Korea and in Europe, although the beef production system in Korea is more intensive than in Europe.

Effects of Dietary Addition of Bentonite and Probiotics on Meat Characteristics and Health of Hanwoo (Bos taurus coreanae) Steers fed Rice Straw As a Sole Roughage Source (a Field Study)

A study was conducted to determine the dietary effects of Na-bentonite (NaB) and probiotics on meat characteristics and health of Hanwoo steers fed rice straw as a sole roughage source. A total of 24 growing Hanwoo steers (avg BW 232 kg) were assigned to two treatments which included a control diet (concentrate mix and rice straw) and a treatment diet (control diet + 0.5-1.0% NaB + 0.5-1.0% probiotics. The diets were fed for 22 months up to the time the animals were slaughtered. Dietary treatment increased (p<0.05) concentrations of trace minerals such as Zn, Cu, and Fe in the longissimus muscle compared to the control. The treatment diet did not affect cold carcass weight, yield traits such as backfat thickness, longissimus muscle area, yield index, yield grade and quality traits such as marbling score, meat color, fat color, texture, maturity and quality grade. Blood profiles of growing steers were within the normal ranges for healthy cattle. In conclusion, feeding a combination of clay mineral and probiotics to Hanwoo steers fed rice straw as a sole roughage source could have a desirable effect on improving trace mineral retention in longissimus muscle without any deleterious effects on carcass traits of steers.

킬레이트화 칼슘 및 게르마늄의 방울토마토 시용에 따른 흡수 특성

펩타이드는 Asp, Glu, Leu을 주요 구성 아미노산으로 하는 한우 혈청을 단백질 분해효소로 분해 후 한외여과를 거쳐 제조하였다. 단백질 분해효소는 alcalase, esperase, flavourzyme, protamex를 이용하였고 alcalase가 가장 좋은 분해력을 나타내어 폡타이드 생산을 위한 혈청 분해에 활용하였다. 한우 혈청으로부터 분리한 펩타이드와 킬레이트 결합한 칼슘 (chelate-Ca)과 게르마늄 (chelate-Ge)을 방울토마토에 적용하여 흡수 변화를 확인하고자 시험을 수행하였다. Chelate Ca을 500, 1,000, 2,000배로 희석하여 방울토마토 재배에 적용한 결과, 처리 농도 및 횟수 증가에 따라 엽과 과실의 칼슘함량이 다소 증가하여 대조처리 Calciolid Ca-300 (3409.1, <TEX>$67.5mg\;kg^{-1}$</TEX>)이 Chelate Ca-200 (3781.1, <TEX>$78.0mg\;kg^{-1}$</TEX>) 보다 처리농도가 높음에도 불구하고 그 함량이 낮아 킬레이트 칼슘의 흡수율이 더 많았다. Chelate Ge을 50, 100, 200배로 희석하여 적용한 결과, 방울토마토 엽의 게르마늄 함량이 처리 농도가 높을수록 많아져 대조구와 Ge <TEX>$132^{(R)}$</TEX>-20 보다 모든 처리구에서 2배 이상의 높은 함량을 나타내었다. 본 연구를 통해 펩타이드와 킬레이트 결합한 칼슘과 게르마늄을 방울토마토에 시용할 경우 그 흡수율이 증가되는 것을 확인하였다. Bloods from slaughtered Korean native cattle (Hanwoo : Bos taurus coreanae) can be used in agriculture with various beneficial effects on the environment. This study was performed to find out the effect of the application of calcium and germanium, which are chelated with peptides made of cattle bloods on the absorption of them by cherry tomato (Lycopersicon esculentum Mill.). Peptide was purified by enzymatic hydrolysis and ultrafiltration from serum protein, which is composed of Asp, Glu, Lue etc. Chelated Ca and Ge were produced by reacting the peptide with <TEX>$CaCl_2$</TEX> and Ge-<TEX>$132^{(R)}$</TEX>. Then, they were applied to cherry tomato during cultivation period at the rate of <TEX>$300mL{\times}3times$</TEX> (10 days interval) for each tomato tree. Application of chelated-Ca increased the Ca contents in leaves and fruits of cherry tomato showing as 19.9% and 23.4% in newerly prepared chelated-Ca-200 (<TEX>$200mg\;L^{-1}$</TEX>), 8.1% and 6.8% in commecrial Calciolid Ca-300 (<TEX>$300mg\;L^{-1}$</TEX>) compared to 3152.6 and <TEX>$63.2mg\;kg^{-1}$</TEX> in control, respectively. Application of chelated-Ge showed the increase in the germanium contents in both leaves and fruits of cherry tomato by over 6 times than those of control and over 4 times than Ge <TEX>$132^{(R)}$</TEX>-20 application. As a result of this study, it seemed that the application of chelated-Ca and chelated-Ge would be more effective than the existing commertial one in the absorption of calcium and germanium by cherry tomato.

Genome Sequence of Oscillibacter ruminantium Strain GH1, Isolated from Rumen of Korean Native Cattle

Oscillibacter ruminantium strain GH1 was isolated from the rumen of Korean native cattle (HanWoo; Bos taurus coreanae). Here, we present the 3.07-Mb draft genome of this strain, which could reveal the presence of certain fiber-specific glycoside hydrolases and butyric acid-producing genes.

Effects of Stocking Density or Group Size on Intake, Growth, and Meat Quality of Hanwoo Steers (Bos taurus coreanae).

This study was conducted to investigate the effects of stocking density or group size on feed intake, daily gain, and carcass characteristics of Hanwoo (Korean indigenous breed) steers reared from 7 months to 31 months of age. Thirty Hanwoo steers were divided into four groups with three replicates each (a total of 12 pens). In each group, one (G1), two (G2), three (G3), and four steers (G4) per pen were allocated as treatments. Pen size was 32.0 m2, and therefore Hanwoo steers in G1, G2, G3, and G4 were reared under different space allowances, i.e. 32.0, 16.0, 10.6, and 8.0 m2/steer, respectively. Steers were reared following a conventional beef cattle management method in Korea, and were offered a fixed amount of commercial concentrate with ad libitum forages. Results were subjected to analysis of variance with stocking density as the main effect, and significance was declared at p<0.05. Although total feed intake was not significantly altered, it numerically increased in animals of low stocking density (G1) compared to those subjected to high stocking density treatment (i.e. G4). Feed conversion ratio was higher (p<0.05) in G3 compared to G1 and G2. Animals in G1 (low stocking density) grew faster (p<0.05) than those of high stocking density (G3 and G4). Back fat thickness, meat yield index, and meat yield grade were similar among all levels of stocking density. However, longissimus muscle area was larger in G1 and G2 (p<0.01) compared to G3 and G4, and animals in G3 produced smaller carcasses (p<0.05). Carcass quality traits, including marbling score, meat color, fat color, texture, maturity and meat quality grade, as determined by a group of experts, were not significantly different among the treatments. In conclusion, lower stocking density resulted in increased feed efficiency, daily gain, and carcass weight in Hanwoo steers. However it remains unclear whether such differences are the results of stocking density or group size, or a combination of both. Nonetheless, these results confirm previous studies reporting a negative effect of increased stocking density on animal productivity. Further, animal welfare under an intensive farming system in relation to economical return is discussed.

Effects of dietary soybean curd residue on the growth performance and carcass characteristics in Hanwoo (Bos taurus coreanae) steer

This study was conducted to determine the effect of dietary soybean curd residue (SCR) on the growth performance and carcass characteristics in Korean native cattle, Hanwoo steer (Bos taurus coreanae). A total of 15 cattle (8 month old and averaging 238.5±12.4 kg in weight) were divided into three dietary groups and then fed a diet containing 0 (T1, control), 25 (T2) and 35% SCR (T3) for 22 months. Meat (M. longissimus dorsi) grade were estimated by the Korean carcass grading system. In growth performance, dry matter intake (DMI) and average daily gain (ADG) were significantly higher in SCR groups (T2 and T3) than T1 group in final fattening period. Feed efficiency of T3 group was higher than other groups for all feeding periods, and carcass weight and marbling score of T3 were higher than other dietary groups. Crude fat content of meat was higher in SCR groups than T1 group. Consequently, dietary SCR could improve growth rate of cattle without any meat quality deterioration. These results may be closely related with the increase of DMI and ADG by dietary SCR. Key words: Longissimus dorsi muscle, dry matter intake, feed conversion, marbling score.

Amino acid differences in interferon-tau (IFN-τ) of Bos taurus Coreanae and Holstein

Interferons (IFNs) are commonly grouped into type I and type II IFN. Type I IFNs are known as antiviral IFNs including IFN-α, IFN-β, and IFN-ω whereas type II IFN is referred to immune IFN and IFN-γ is only member of the type II IFN. Type I IFNs are induced by virus invading however type II IFN is produced by mitogenic or antigenic stimuli. IFN-τ was first identified in ruminant ungulates as a pregnancy recognition hormone, trophoblastin. IFN-τ constitutes a new class of type I IFN, which possesses the common features of type I IFN, such as the ability to prevent viral infection and to limit cell proliferation. In addition, IFN-τ is unique in that it is induced by pregnancy unlike other type I IFNs. We cloned Bos taurus (B. T.) Coreanae IFN-τ from peripheral blood mononuclear cells. The amino acid sequence of B. T. Coreanae IFN-τ shares only 90.3% identity with that of Holstein dairy cow. Recombinant B. T. Coreanae and Holstein IFN-τ proteins were expressed in Escherichia coli and the antiviral activity of IFN-τ proteins were examined. Both recombinant proteins were active and protected human WISH and bovine MDBK cells from the cytopathic effect of vesicular stomatitis virus. The recombinant IFN-τ protein of B. T. Coreanae and Holstein properly induced the expression of antiviral genes including 2′,5′-oligoadenylate synthetase (OAS) and Mx GTPase 1 (Mx-1).

Effects of mulberry (Morus alba L) silage supplementation on the haematological traits and meat compositions of Hanwoo (Bos taurus coreanae) steer

This study was conducted to evaluate the effect of dietary supplementation with mulberry silage on hematologic traits and meat compositions in Hanwoo (Bos taurus coreanae) steer fed total mixed rations and to determine application possibility of mulberry silage as a functional feed source in the beef industry. Twenty steer (622.5±12.7 kg) of the late fattening stage were assigned to either a group with mulberry silage supplementation (MSS) or without (control). No significant differences were found in serum total protein and albumin concentrations. There was no difference between control and MSS in serum cholesterol concentrations but a significant difference (P<0.05) was noted in serum cholesterol concentrations before and after the experiment for the MSS. Dry matter and ether extract content of Longissimus dorsi for MSS were significantly higher (P<0.05) than those for control. However, crude protein of L. dorsi was significantly lower (P<0.05) in MSS than in control. Although no significant change was apparent in content of saturated fatty acids in L. dorsi between control and MSS, some fatty acids including arachidate and behenate were significantly (P<0.05) changed with mulberry silage supplementation. Total free amino acids showed similar levels in the two groups. Levels of most free amino acids were significantly higher (P<0.05) in MSS than in control. In conclusion, MSS changed the serum biochemistry in Hanwoo steer of the late fattening stage and caused relative alterations of chemical composition in L. dorsi. Key words: Hanwoo steer, mulberry silage, meat composition, fatty acid composition, free amino acid.

Effect of mulberry silage supplementation during late fattening stage of Hanwoo (Bos taurus coreanae) steer on antioxidative enzyme activity within the longissimus muscle

This study was conducted to determine the possible application of mulberry silage as a functional feed in the feeding management of Hanwoo, Korean native cattle, for high quality beef production. Twenty Hanwoo steers in the last stage of fattening were randomly assigned to two groups with (MSS) or without (Control) supplemental mulberry silage. The Control group was fed on a standard total mixed commercial ration, while the MSS group was fed on a total mixed commercial ration formulated with mulberry silage at the rate of 10%, fresh matter basis, for 30 days. The mulberry silage contained active ingredients such as 1-deoxynojirimycin, γ-aminobutyric acid, and phenol compounds. In the present study, the oxidative stress biomarkers such as glutathione, superoxide dismutase, glutathione peroxidase, catalase, and glutathione-S-transferase were improved in the MSS group compared with the Control group. Electron spin resonance assays showed that 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was significantly elevated by 75.5% in the MSS group (P &lt; 0.001). Moreover, the MSS group exhibited stronger scavenging activity against hydroxyl radicals, superoxide radicals, and alkyl radicals, and the radical scavenging activity occurred in a dose-dependent manner. Findings from the present study suggest that mulberry silage may be useful as a functional feed by improving the antioxidant activity against various reactive radicals for beef cattle.

Sequence variations of the bovine prion protein gene (PRNP) in native Korean Hanwoo cattle

Bovine spongiform encephalopathy (BSE) is one of the fatal neurodegenerative diseases known as transmissible spongiform encephalopathies (TSEs) caused by infectious prion proteins. Genetic variations correlated with susceptibility or resistance to TSE in humans and sheep have not been reported for bovine strains including those from Holstein, Jersey, and Japanese Black cattle. Here, we investigated bovine prion protein gene (PRNP) variations in Hanwoo cattle [Bos (B.) taurus coreanae], a native breed in Korea. We identified mutations and polymorphisms in the coding region of PRNP, determined their frequency, and evaluated their significance. We identified four synonymous polymorphisms and two non-synonymous mutations in PRNP, but found no novel polymorphisms. The sequence and number of octapeptide repeats were completely conserved, and the haplotype frequency of the coding region was similar to that of other B. taurus strains. When we examined the 23-bp and 12-bp insertion/deletion (indel) polymorphisms in the non-coding region of PRNP, Hanwoo cattle had a lower deletion allele and 23-bp del/12-bp del haplotype frequency than healthy and BSE-affected animals of other strains. Thus, Hanwoo are seemingly less susceptible to BSE than other strains due to the 23-bp and 12-bp indel polymorphisms.

거세 한우 육성우 사육밀도가 채식행동에 미치는 영향

This study was carried out to investigate the effects of stocking density on the eating and ruminating behavior of growing Hanwoo steer (Bos taurus coreanae). A total of thirty growing Hanwoo steers were divided into four stocking density groups (G1: 1 head/32 m 2 , G2: 2 heads/32 m 2 , G3: 3 heads /32 m 2 , G4: 4 heads/32 m 2 ) with 3 replicates (12 pens). The results of eating behaviors for 48 hours are summarized as follows: Total intake was higher in 2G, 3G and 4G than in 1G, but not significantly different among thetreatments. Intake of roughage was the highest in 2G (3.32 kg), while 1G (2.85 kg) was the lowest (P 2G> 3G > 4G (P 4G > 2G > 3G (P<0.05). However, stocking density had no effect on drinking and defecating. Eating rate and chewing efficiency were the highest in 4G (P<0.01, 0.05), but

한우(Bos taurus coreanae)의 CAST 유전자 내 변이지역 탐색 및 경제형질과의 연관성 분석

Calpastatin (CAST)은 calpain의 억제제 역할을 하는 유전자이며 BTA7에 위치하고 있다. Calpain을 억제하는 CAST 유전자 내 다형성이 육질의 연도에 영향을 미치고 있는 것이 알려져 있다. 또한 여러 연구를 통해 calpain 시스템은 일반 골격근의 성장에 중요한 역할을 하는 것으로 보고되었다. 따라서 본 연구는 한우 집단의 CAST 유전자 내 변이 지역을 탐색하여 경제형질과의 연관성을 분석하기 위하여 실시하였다. CAST 유전자(Accession no. NC_007305) 단일염기변이지역을 탐색 결과 총 5개의 변이(109749T/C, 116151G/A, 109737G/A, 109823T/C, 109926G/A) 지역이 탐색 NCBI에 등록되어 있지 않은 새로운 변이로 본 연구를 통해 탐색되었다. 한우집단 내에서 탐색된 총 5개의 SNP를 대상으로 연관불균형(LD, Linkage disequilibrium) 분석을 수행하였다. 변이들 간의 연관불균형(LD) 정도가 가장 낮은 수준에 있는 2개의 변이지역(109926G/A와 116151G/A, <TEX>$r^2$</TEX>=0.038)을 대상으로 경제형질과의 연관성 분석을 실시한 결과 등심단면적(109926G/A, p<0.05)과 18개월령 체중(116151G/A, p<0.05)에서 유의적인 연관성이 검출 되었다. CAST유전자는 도축 후 숙성과정에서 고기의 연도를 증가시키는데 영향을 미칠 뿐만 아니라 가축의 성장에도 깊은 연관성이 있으며, 본 연구를 통해 CAST 유전자 내 변이는 성장 관련 형질과의 연관성이 유의적인 것으로 확인되었다. A number of studies have shown that the calpain system is important in normal skeletal muscle growth. An increased rate of skeletal muscle growth can result from a decreased rate of muscle protein degradation, and this is associated with a decrease in activity of the calpain system, due principally to a large increase in calpastatin (CAST) activity. The CAST gene, mapped to BTA 7, is considered a candidate gene for beef tenderness and muscle growth. The present study used comparative sequencing of five novel polymorphisms located within exon 20 and 22 of the bovine CAST gene in Hanwoo: exon20- 109737G/A, 109749T/C, 109823T/C, exon22- 116151G/A, intron- 109926G/A. The association of the CAST SNPs with economic traits was studied. The 109926G/A showed a significant effect only on the longissimus muscle area (LMA, p<0.05) in Hanwoo. 109926G/A with the genotype GG had a significantly higher effect on LMA (75.35) than the genotype AA (69.6, p<0.05). Also, the 116151G/A showed a significant effect only on weight at 18 months (W18, p<0.05). 116151G/A with the genotype GG had a significantly higher effect on W18 (428.54) than the genotype AA (408.87, p<0.05).

Effects of Dietary Addition of Bentonite on Manure Gas Emission, Health, Production, and Meat Characteristics of Hanwoo (Bos taurus coreanae) Steers

A study was conducted to determine the dietary effects of a clay mineral (sodium bentonite, NaB) on manure gas emission, health, production, and meat characteristics of Hanwoo steers. Two diets fed to steers included a control diet (concentrate mix and rice straw) and a treatment diet (control diet+1.0% clay mineral/concentrate mix). Dietary NaB addition considerably reduced concentrations of gases (H2S, SO2 and NH3) in the manure of Hanwoo steers. Growing steers fed NaB had similar blood profiles with the exception of lower (p 0.05) fatty acid composition. The study demonstrated that the dietary addition of a clay mineral could be effective in improving mineral bioavailability to Hanwoo steers, which could be one of the reasons for their improved performance. (Key Words : Clay Mineral, Bentonite, Production, Meat Quality, Hanwoo)

Effect of cytoplasmic lipid content on in vitro developmental efficiency of bovine IVP embryos

The objective was to evaluate the effect of cytoplasmic lipid content on the embryonic developmental efficiency of bovine in vitro embryo production (IVP) embryos. Ovaries from Korean native cows (Bos taurus coreanae) were collected from a local abattoir, and cumulus-oocyte complexes (COCs) were recovered from follicles 2 to 8 mm in diameter. The oocytes were divided into three groups, dependent on their cytoplasm color: pale color (PC), brown color (BC), and dark color (DC). The COCs were fertilized using frozen-thawed semen from a single Hanwoo bull. Based on measurement of the cytoplasmic color intensity of oocytes after 22 h of in vitro maturation (IVM), the DC group had lower (P < 0.05) color intensity than that in the BC and PC groups (56.3 ± 2.7, 93.3 ± 5.1, and 123.9 ± 12.0, respectively). Based on MitoTracker Green FM staining, the number of mitochondria in the DC (170.1 ± 31.2) group was significantly higher than that in the BC (137.5 ± 30.8) and PC (105.5 ± 25.3) groups. The cleavage rate in the DC (81.5%) group was also higher than that in the PC (50.4%) group (P < 0.05), as was the development rate to blastocyst stage (18.9% vs. 9.8%). Finally, cell numbers of blastocysts in the DC (150.8 ± 28.0) group were higher (P < 0.05) than that in the BC (107.6 ± 17.8) and PC (80.5 ± 12.3) groups. In conclusion, cytoplasm color was a useful selection parameter for abattoir-derived oocytes destined for IVP.

Cloning and expression of a prion protein (PrP) gene from Korean bovine (Bos taurus coreanae) and production of rabbit anti-bovine PrP antibody

A PrP gene, from a Korean bovine, exhibiting a nonsense and a missense polymorphism respectively at nucleotides 576 and 652 has been cloned. The latter resulted in Glu to Lys substitution at amino acid residue 218. After expression and purification of the recombinant bovine PrP (recBoPrP) with Glu218Lys substitution, a polyclonal antibody against this protein was raised. ELISA and Western blot analysis suggested that the recBoPrP obtained in this study had a unique conformation not presented in native PrP(C), and the polyclonal antibody recognized PrP in a conformation dependent manner. These reagents will be valuable tools for studying PrP conformation.

Genetic Relationship of Gestation Length with Birth and Weaning Weight in Hanwoo (Bos Taurus Coreanae)

The genetic relationship of gestation length (GL) with birth and weaning weight (BW, WW) was investigated using data collected from the Hanwoo Experiment Station, National Institute of Animal Science, RDA, Republic of Korea. Analytical mixed models including birth year-season, sex of calf, linear and quadratic covariates of age of dam (days) and linear covariate of age at weaning (days) as fixed effects were used. Corresponding restricted maximum likelihood (REML) and Bayesian estimates of variance components and heritability were obtained with two models; Model 1 included only direct genetic effect and Model 2 included direct genetic, maternal genetic and permanent environmental effect. All the genetic parameter estimates from REML were corresponding to the Bayesian estimates. Direct heritability estimates for GL, BW, and WW were 0.48, 0.33 and 0.25 by Model 1. From Model 2, direct and maternal heritability estimates were 0.38 and 0.03 for GL, 0.14 and 0.05 for BW, and 0.08 and 0.05 for WW. Genetic correlation estimates between direct and maternal effects were 0.05 for GL, 0.59 for BW, and 0.52 for WW. Estimates of direct genetic correlation between GL and BW (WW) were 0.44 (0.21). Positive genetic correlation of GL with BW and WW imply that selection for greater BW or WW would lead to prolonged gestation length.

Genotype distribution of the prion protein gene (PRNP) promoter polymorphisms in Korean cattle

Recently, an association between bovine spongiform encephalopathy (BSE) and insertion/deletion (indel) polymorphisms in the bovine prion protein gene (PRNP) promoter region has been reported in German cattle. These PRNP polymorphisms cause changes in PRNP expression and are thought to play an important role in BSE susceptibility. BSE has been reported in British and Japanese Holstein cattle but has not been diagnosed in Hanwoo cattle (Bos taurus coreanae) up to now. These results prompted us to investigate the genotype distributions of these PRNP promoter polymorphisms in 107 Hanwoo cattle and 52 Holstein cattle and compare the results with those of previous studies. A significant difference (P=0.0249) in allele frequency of the 23 bp indel polymorphism was observed between Hanwoo and the BSE-affected German cattle previously investigated. There were no significant differences in the genotype (P=0.2095) or allele (P=0.8875) frequencies of the 12 bp indel polymorphism between Hanwoo and BSE-affected German cattle. Interestingly, the genotype and allele frequencies of the 23 bp indel polymorphism in Korean Holsteins were very similar to those previously reported for BSE-affected German cattle and healthy US cattle sires.

Leptin Polymorphisms Associated with Carcass Traits of Meat in Korean Cattle

Leptin has been investigated as a candidate gene for fat characteristics in beef cattle. Previously, we have reported 57 sequence variants discovered in Korean cattle (Bos Taurus coreanae). In this study, we examined the association between polymorphisms of leptin and carcass traits (cold carcass weight (CWT) and marbling score (Marb)) in Korean cattle. Among 57 polymorphisms, 11 common polymorphic sites were genotyped in our beef cattle (n = 437). Statistical analysis revealed that one single nucleotide polymorphism in coding exon (c.+411T>C (A137A)) showed a significant association with the yield trait, CWT. The C-bearing genotypes (CC or CT) of c.+411T>C (A137A) showed the higher CWT (p = 0.006). c.+150C>G (S50S) also showed a significant association with the quality trait, Marb (p = 0.01). Our findings suggest that polymorphisms in leptin might be one of the important genetic factors that influence carcass yield and quality in beef cattle, especially in CWT and Marb.

Effects of Spent Composts of Selenium-enriched Mushroom and Sodium Selenite on Plasma Glutathione Peroxidase Activity and Selenium Deposition in Finishing Hanwoo Steers

Effects of spent composts of selenium-enriched mushroom (Se-SMC) on plasma glutathione peroxidase (GSH-Px) activity and selenium (Se) deposition in finishing Hanwoo (Bos taurus coreanae) steers were investigated. Twenty-five Hanwoo steers (average body weight = 613 kg, average age = 22 months) were allotted to treatments in five groups of five steers per pen for 12 weeks preceding slaughter. Treatments were SMC alone (CON; 0.1 ppm Se), 0.3 ppm (0.3 Se-SMC), 0.6 ppm (0.6 Se-SMC), 0.9 ppm (0.9 Se- SMC), and 0.9 ppm (sodium selenite; SENI) Se. During the experimental period, blood samples were taken to analyze Se concentrations and GSH-Px activities. Muscle and liver samples were collected for analyses of Se contents after slaughter. Dry matter intake and body weight gain were not affected by Se-SMC or sodium selenite supplementation. Selenium concentration in the whole blood and GSH-Px activity in plasma were linearly increased (p<0.01) with increasing levels of Se-SMC. The whole blood Se concentration of SENI treatment was significantly higher (p<0.05) than that of CON treatment from 4 weeks, whereas there was no significant difference in GSH-Px activities between both treatments at 8 and 12 weeks. Selenium content in the hind leg and liver increased linearly (p<0.05) with increasing levels of Se-SMC, but those of SENI treatments were not significantly different from CON treatments. These results suggested that Se in the Se-SMC was highly bioavailable to blood and tissues of ruminants, especially compared with Se in the sodium selenite. Therefore, Se-SMC might be used not only as an inexpensive way of providing Se for ruminants but also as another way of