• Journal of Embryo Transfer
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• v.25 no.3
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• pp.141-144
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• 2010

In vivo embryo produced from Hanwoo donor cows were collected and transferred to Hanwoo recipients. Cows, at random stages of the estrous cycle, received Progesterone Releasing Intravaginal Device (CIDR-plus, InterAg, New Zealand) together with injection of 1 mg estradiol benzoate and 50 mg progesterone, and gonadotropin treatment began 4 day later. For superovulation, a total of 28 mg FSH was intramuscularly injected twice a day in the way of decreasing doses 4 day (5, 5, 4, 4, 3, 3, 2 and 2 mg). Twenty one Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered 7 days after the second insemination by flushing the uterus with Embryo Collection Medium. The results obtained were as follows: The rates of transferable embryos were 50.3%, and 78 fresh embryos at morulae and blastocysts stage were transferred into Hanwoo recipients on day 7 of estrus cycle. The pregnancy rates were first embryo transfer 55.6%, 2nd 62.9% and 3rd 57.9%, respectively. In conclusion, These results suggest that CIDR-based superovulation protocol may be effectively used for production of superior Hanwoo embryos. Also, since it seems the condition of recipient cows greatly affect pregnancy rate, it is very important to evaluate recipient for effective cattle production.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.607-616
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• 2002

This study analyzed the effects of pH, sex, backfat thickness, ribeye area, cold carcass weight, shipping month, muscle internal temperature, average daily temperature, and average relative humidity for slaughtered Hanwoo to meat color by season. The analyses focused on interaction and each effect to meat color of the factors. For the result for analysis of multiple linear regressions, meat color values were decreased as pH increased in all meat color, and the meat color values increased as the backfat thickness was increased. As the results of the decision tree analysis by each factor, cow and steer slaughtered in spring and autumn were the highest in the lightness(L*). The redness(a*) was the cases that pH was less than 5.63 and average relative humidity was over than 71.5% for Hanwoo slaughtered in autumn. The chroma(C*) value was the highest for Hanwoo that was slaughtered in summer and autumn, the pH was less than 5.60, and the back fat thickness was over than 8 mm. The hue angle($h^0$) was shown that the muscle internal temperature was less than 4.7$^{\circ}C$ among Hanwoo which was slaughtered in spring, summer, and autumn, the pH was less than 5.66, and the back fat thickness was over than 8 mm.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.213-223
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• 2012

In this study, two experiments were conducted to evaluate the total mixed ration with fermented feed (TMRF) and total mixed ration (TMR) by rumen in vitro fermentation and their effects on the growth performance and blood characteristics of Hanwoo steers. In experiment 1, three Hanwoo steers ($600{\pm}47$ kg), each permanently fitted with a ruminal cannula were used. In this experiment, three diets designated as T1, TMRF (18.4% fermented feed, tall fescue, mammoth wild rye forage and whole crop barley); T2, TMRF (17.7% fermented feed, rice straw and whole crop barley); and T3, TMR (rice straw, whole crop barley and probiotics, but no fermented feed), which were subjected to rumen in vitro fermentation for 48 h. The results demonstrated that DM disappearance rate gradually increased with advancing fermentation time, but T1 and T2 were higher than the T3 (p<0.05) from 3 h to 12 h, but insignificant (p>0.05) at 24 and 48 h. None of the specific VFAs were affected except for acetic and non volatile lactic acids, which were produced more in T2 than in T1 and T3 at 24 h and 48 h of incubation. A/P was lower in T1 and T2 than inT3 at 24 h (p<0.05) and 48 h (p>0.05) of incubation. These results confirmed that TMRF-related treatment shows a superior performance to that of TMR during the ruminal fermentation period. In experiment 2, the three diets in experiment 1 plus 1 more control diet (concentrates, probiotics and 2% rice straw of body weight) were fed to the 48 Hanwoo steers ($160{\pm}10$ kg) for a period of 168 d. The results demonstrated that the daily and total live weight gain and feed efficiency were higher (p<0.05) in the TMRF and TMR groups than in the control group. SGOT, SGPT and BUN (p<0.05) were reduced in TMRF relative to the control and TMR groups by 168 d which confirmed that TMRF shows better blood profiles than the TMR and control groups. Overall, these results appear to show that TMRF has better in vitro ruminal characteristics than those of TMR; growth performance and blood profiles were also found to be superior in TMRF than in the TMR and control groups. Thus, our findings suggest that TMRF-based feed supplies are favorable for Hanwoo cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.11
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• pp.1553-1558
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• 2012

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 $32.0m^2$, 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 $8.0m^2$/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.

• Journal of Animal Science and Technology
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• v.44 no.6
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• pp.677-684
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• 2002

We have investigated the expression patterns of candidates for growth stage specifically expressed genes. The expression patterns of the EPV20, aldolase A, Translationally Controlled Tumor Protein (TCTP) and Adipocyte Differentiation Related Protein (ADRP) were examined by semiquantitative RT-PCR and northern blot analysis in skeletal muscle tissues of Hanwoo, especially in the longissimus dorsi at various growth stages. The EPV20 mRNA was expressed in longissimus dorsi tissue of Hanwoo, but there was no difference of expression levels during growth stages. Though the aldolase A gene was reported to be muscle-specific and regulated at developmental stages, the expression levels of aldolase A mRNA in the longissimus dorsi tissues showed little differences at various growth stages. The expression levels of TCTP which was reported as growth-related protein regulated at translation step were gradually increased during growth of Hanwoo. The expression levels of ADRP mRNA were rapidly increased at 24-month-old longissimus dorsi tissue of Hanwoo, and decreased at 30-month-old. Our data suggest that the ADRP gene show as growth-stage dependent expression and is related to fat deposition within muscular tissue.

• Journal of Life Science
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• v.29 no.12
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• pp.1314-1320
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• 2019

This study aimed to identify single nucleotide polymorphisms in exon 8 region of the calmin (CLMN) gene and to evaluate their associations with meat yield and quality traits in Hanwoo (Korean cattle). We compared gene expression pattern of CLMN between high and low marbling score groups with extremely different intramuscular fat content of the longissimus lumborum muscles in Hanwoo. The CLMN gene was highly expressed in the high marbling score group. Total of nine SNPs were identified in the exon 8 region of CLMN gene, genotyping of the SNPs was carried out using direct-sequencing analysis in Hanwoo population (n=300) to evaluate their association with meat yield and quality traits. As a result, g.23249G>C in exon 8 was significantly associated with marbling score. Animals with the CC and GC genotypes had higher marbling score than those with the GG genotype. We constructed haplotypes of CLMN gene by linkage disequilibrium analysis and analyzed association between haplotypes and meat yield and quality traits. Haplotype of CLMN gene was associated with marbling score. As a result, animals with the CC-CC haplotype (g.23249G>C and g.23465T>C SNPs) had higher marbling score than those with CT and GT haplotypes. These findings suggest that the SNPs of bovine CLMN gene may be a useful molecular marker for selection of meat quality traits in Hanwoo.

• Journal of Embryo Transfer
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• v.15 no.1
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• pp.47-56
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• 2000

This study was carried out to improve a technique of embryo transfer for twin calves production in Hanwoo cattle. Blastocysts for the donor of embryo transfer were classified into three criteria by accessment of morphology; early blastocyst, blastocyst and expanded blastocyst. Tow embryos were introduced transcervically into utrerine horn either of Hanwoo or Holstein by ipsilaterally or contralaterally to the corpus luteum. Thiry-six out of 57 recipients cows were inseminated by artificially on the next day of estrus, and followed by transfer of embryos into contralaterally. The pregnance rates of recipients following transfer of bovine embryos of day 7, 8 and 9 was 43.5, 18.2 and 8.3%, respectively. These results appeared that these was a significant (P<0.05) difference between on day-7 embryos and day-9 embryos, but not between on day-8 and day-9 embryos. Although there was not significant(P<0.05) difference in the pregnancy rates between the blastocysts(11/25, 44%) and expanded blastocysts(2/19, 10.5%) and between the blastocysts and early blastocysts(2/13, 15.4%), the embryos at blastocyst stage are more suitable than others for obtaining higher rate of pregnancy. There was no significant difference on pregnancy of the embryos transferred prior to presence(6/21, 29%) or absence (9/36, 25%) of artificial insemination. On pregnancy of Holstein, 2(15.4%) out of 13 recipients were pregnant in heifer. Similar Pregnancy rates were obtained between 1∼2 parities and 3∼4 parities by 30% (6/20) and 27.3%(3/11), respectively. Taken together, there was not significant difference in pregnancy rate due to small number of recipients used for this experiment. Both of Hanwoo and Holstein introduced the embryos by contralsterally to the corpus luteum were slightly higher pregnancy rate compare to by ipsilaterally (12/41, 29.3% vs, 3/16, 18.8%). The ratio of production of twin and single calves in Holstein was 20% (9/45) and 2.2% (1/45), respectively. However, in Hanwoo cows both of production of twin and single were similar as 8%. This result suggests that Holstein as recipients was superior to Hanwoo cows for production of twin calves. Out of all 15 pregnant, 12(80%) were produced a total of 22 normal calves in which the others composed of abnormal, as judging as 2(13.3%) for abortion and 1(6.6%) for stillbirth during the pregnant period.

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.311-317
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• 2011

The aim of this study was to evaluate the association between economic traits of Korean cattle (Hanwoo) and genetic variation in fatty acid binding protein 5 (FABP5) gene within QTL region of carcass weight and marbling score traits on BTA 14. We sequenced for detection of single nucleotide polymorphism (SNP) with 24 unrelated Hanwoo samples and identified four SNPs (-1141A>G, 949A>G, 969A>G and 1085C>G). Relationship between the genotypes of 583 Hanwoo individuals by PCR-RFLP and economic traits were analyzed by the mixed regression model implemented in the ASReml program. As the result of statistical analysis, SNP1 (-1141A>G) showed significant effect (p<0.003) on marbling score (MS) and SNP2 (949A>G) showed significant effect (p<0.034) on eye muscle area (EMA). Further studies are required to validate the significant SNPs in a bigger population, but the SNPs (-1141A>G and 949A>G) of FABP5 could be a genetic marker to estimate molecular breeding value (MEBV) for carcass traits in Hanwoo.

• Journal of Animal Science and Technology
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• v.50 no.2
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• pp.151-156
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• 2008

The study aimed to estimate genetic parameters of body weights in Hanwoo steers using random regression model and compare it with single trait animal model. A total of 1,372 Hanwoo steers that belonged to progeny testing program of the Hanwoo Genetic Improvement conducted at the Livestock Improvement Main Center of the National Agricultural Cooperative Federation (LIMC-NACF) in Rep. of Korea were used. Results of the random regression model fitting quadratic function revealed heritability values from 0.17 to 0.30 for the whole testing days up to 800 days. The results of the animal model showed estimated heritability values ranged from 0.24 to 0.36. Estimates of permanent environmental correlations tended to increase with increasing test in days. Unlike in the direct genetic correlation that at early stage the estimate was slightly negative it was 0.30 then increased to approach unity at later stage of test. Comparing the results between random regression model and the animal model showed not much differences and both followed similar pattern and therefore the use of random regression model for the national genetic evaluation of Hanwoo could be implemented.

• Journal of Animal Science and Technology
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• v.52 no.6
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• pp.505-511
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• 2010

Thirty six Hanwoo steers (average BW, $564.5\;{\pm}\;25.7\;kg$; average age, approximately 23 months) were used to evaluate the effects of a mixture of eugenol (14%), thymol (1%) and malate (85%) on growth performance, beef quality and liver function in Hanwoo finishing steers fed a high-concentrate diet. A feeding trial was conducted for 7 months in National Agricultural Cooperative Federation farm located in Anseong, Korea. Steers were assigned randomly to one of three treatments: control (without additive supplementation), treatment 1 (0.05% additive of concentrate), treatment 2 (0.1% additive of concentrate). The results of this study showed that initial and final BW averaged 564 and 755 kg, respectively, and BW gain was significantly higher (P<0.05) for steers fed the additive mixture than for those fed no mixture (0.78 and 0.79 vs. 0.69 kg/d, respectively). Serum aspartate aminotransferase in the T2 treatment was decreased during the 24 to 31 months of age. Although supplementation of additives resulted in no substantial effect on carcass characteristics, it had a potential effect to improve feed efficiency and AST concentration in Hanwoo finishing steers fed a high-concentrate diet. In conclusion, a mixture of eugenol, thymol and malate has shown promise in improving feed efficiency and liver function in the finishing phase of Hanwoo steers.