• Asian-Australasian Journal of Animal Sciences
• /
• 제31권7호
• /
• pp.1043-1061
• /
• 2018

Intramuscular fat (IMF) content in skeletal muscle including the longissimus dorsi muscle (LM), also known as marbling fat, is one of the most important factors determining beef quality in several countries including Korea, Japan, Australia, and the United States. Genetics and breed, management, and nutrition affect IMF deposition. Japanese Black cattle breed has the highest IMF content in the world, and Korean cattle (also called Hanwoo) the second highest. Here, we review results of research on genetic factors (breed and sex differences and heritability) that affect IMF deposition. Cattle management factors are also important for IMF deposition. Castration of bulls increases IMF deposition in most cattle breeds. The effects of several management factors, including weaning age, castration, slaughter weight and age, and environmental conditions on IMF deposition are also reviewed. Nutritional factors, including fat metabolism, digestion and absorption of feed, glucose/starch availability, and vitamin A, D, and C levels are important for IMF deposition. Manipulating IMF deposition through developmental programming via metabolic imprinting is a recently proposed nutritional method to change potential IMF deposition during the fetal and neonatal periods in rodents and domestic animals. Application of fetal nutritional programming to increase IMF deposition of progeny in later life is reviewed. The coordination of several factors affects IMF deposition. Thus, a combination of several strategies may be needed to manipulate IMF deposition, depending on the consumer's beef preference. In particular, stage-specific feeding programs with concentrate-based diets developed by Japan and Korea are described in this article.

• 한국식품과학회지
• /
• 제26권5호
• /
• pp.500-506
• /
• 1994

한우육(1등급), 유우육, 교잡종우육 및 호주산 수입우육의 등심부위를 구입하여 각종의 쇠고기 품질을 비교, 평가하기 위하여 연도, 다즙성 및 풍미에 관련되는 성분을 분석함과 아울러 관능검사를 실시하였다. 풍미에 관련되는 화학적 성분들로서는 비단백태질소, 핵산물질, 지방산, 유리아미노산 등을 분석하였고 쇠고기의 연도 측정을 위해 Hydroxyproline, 보수력, 근내지방함량 분석 및 Instron을 이용한 연도측정을 하였다. 또한 쇠고기의 기호성 및 풍미특성을 비교, 평가하기 위해 주관적 평가방법인 삼점검사와 정량적 묘사분석을 수행하였다. 풍미에 관련되는 비단백태질소, 핵산물질, 지방산, 유리아미노산 등을 분석한 결과, 비단백태질소는 한우육이 가장 낮아 도살후 저장기간이 가장 짧은 것으로 판단되며, 핵산물질은 한우육이 가장 높았다. 유리아미노산 함량은 한우육이 가장 낮았으나 염기성 아미노산과 방향족 아미노산의 상대적 비율은 가장 높았던 반면, 황함유 아미노산의 함량은 수입육이 가장 높았다. TBA가(價)는 한우육이 가장 낮았고, 지방산의 구성을 볼 때 한우육의 불포화지방산 비율은 수입우육이나 유우육보다 높았으나 교잡종우육과는 비슷하였다. 연도는 Instron을 이용한 경도측정에서 수입우육과 교잡종우육이 한우육과 유우육보다 질긴 것으로 나타났으며, 콜라젠 함량은 유우육이 가장 높았고 한우육이 가장 낮았다. 다즙성을 부분적으로 반영하는 보수력은 한우육이 가장 높았고 아울러 pH도 가상 높았다. 근내지방함량도 한우육이 가장 높아 다즙성이 우수한 것으로 판단되었다. 관능검사 결과, triangle test에서는 한우육과 수입우육, 한우육과 교잡종우육, 수입우육과 교잡종우육간의 차이를 관능검사요원들이 구별하였다. 그러나 정량적 묘사분석 결과 다즙성을 제외하고는 냄새, 풍미, 연도에서 품종간 차이가 발견되지 않았다. 한우의 비휘발성 풍미성분은 다른 쇠고기 시료에 비해 높은 경향을 나타냈음에도 불구하고 주관적 기호성 평가에서는 유의차를 나타내지 못했다. 이것은 한국인들이 아직 쇠고기 품질 특성에 대한 객관적 평가기준을 인식하지 못하고 있어 여러가지 쇠고기간의 비교평가는 할 수 있지만, 개별 쇠고기에 대한 절대평가는 제대로 할 수 없다는 것을 보여준다.

• 한국환경농학회:학술대회논문집
• /
• 한국환경농학회 2009년도 정기총회 및 국제심포지엄
• /
• pp.273-282
• /
• 2009

The transmissible spongiform encephalopathies (TSEs) disease group are fatal neurodegenerative disorders affecting a wide range of hosts. The group includes kuru and Creutzfeldt-Jakob disease (CJD) in humans, scrapie in sheep and goats and Bovine spongiform encephalopathy (BSE) in cattle. The exact nature of the infectious agent involved in the transmission of these diseases remains controversial. However, a central event in their pathogenesis is the accumulation in infected tissues of an abnormal form of a host-encoded protein, the prion protein (PrP). Whereas the normal cellular protein is fully sensitive to protease ($PrP^{sen}$), the disease-associated prion protein ($PrP^d$) is only partly degraded ($PrP^{res}$), its amino-terminal end being removed. BSE was first reported in the mid-80s in the UK. Ten years later, a new form of human prion disease, variant CJD (vCJD) developed in the wake of the BSE epidemic, and there is now strong scientific evidence that vCJD was initiated by the exposure of humans to BSE-infected tissues, thus indicating a zoonotic disease. However, the ban on the feeding of animal-derived proteins to ruminants, and the apparent lack of vertical transmission of BSE, have led to a decline in the incidence of the disease within cattle herd and therefore, an assumed decreased risk for human contacting vCJD. The origin of the original case(s) of BSE still remains an enigma even though three hypotheses have been raised. Hypotheses are i) sheep- or goat-derived scrapie-infected tissues included in meat and bone meal fed to cattle, ii) a previously undetected sporadic or genetic bovine TSE contaminating cattle feed or iii) originating from a human TSE through animal feed contaminated with human remains. A host cellular membrane protein ($PrP^C$), which is abundant in central nervous system tissue, appear to be conformationally altered in the diseased host into a prion protein ($PrP^{Sc}$). This $PrP^{Sc}$ is detergent insoluble and partially protease-resistant ($PrP^{res}$). The term $PrP^{res}$ is normally used to describe the protein detected after protease treatment, in techniques such as Western immunoblotting, and enzyme-linked immunosorbant assay using fresh/frozen tissue. Immunohistochemistry may performed with formalin-fixed tissues. Also, clinical signs of the BSE are one of the major diagnostic indicators. Recently, atypical forms (known as H- and L-type) of BSE have appeared in several European countries, Japan, Canada and the United States. An unusual case was also reported in a miniature zebu. The atypical BSE fall into two groups based on the relative molecular mass (Mm) of the unglycosylated $PrP^{res}$ band relative to that of classical BSE, one of the higher Mm (H-type) and the other lower (L-type). Both types have been detected worldwide as rare cases in older animals, at a low prevalence consistent with the possibility of sporadic forms of prion diseases in cattle. This raises the unwelcome possibility that vCJD could increase in the human population. Now, active surveillance program against BSE is going on in Korea. In regional veterinary service lab, ELISA is applied to screen the BSE in slaughter and confirmatory tests by Western immunoblotting and immunohistochemisty are carried out if there are positive or suspect in the screening test. Also, the ruminant feed ban is rigorously enforced. Removal of specified risk materials such as brain and spinal cord from cattle is mandatory process at slaughter to prevent the infected material from entering the human food chain.

• Asian-Australasian Journal of Animal Sciences
• /
• 제16권7호
• /
• pp.1046-1048
• /
• 2003

A polymerase chain reaction (PCR) assay was developed to differentiate buffalo meat from the meat of Ceylon spotted deer (Axis axis ceylonensis), Ceylon sambhur (Cervus unicolor unicolor), cattle (Bovine), goat (Caprine), pig (Porcine), and sheep (Ovine). A set of primers were designed according to the sequence of the mitochondrial cytochrome b gene of bubalus bubalis and by PCR amplification a band of approximately 242 bp band was observed with buffalo DNA. These primers did not cross-react with DNA of other animal species tested in the study under the specified reaction conditions. A band of 649 bp was observed for all animal species tested when DNA was amplified with the universal primers indicating the presence of mitochondrial DNA in the samples. The technique was sensitive enough to identify rotten (10 days post slaughter), dried and cooked buffalo meat. The absence of a cross reaction with human DNA using the buffalo specific primers eliminates possible false positive reactions.

• 한국수의병리학회:학술대회논문집
• /
• 한국수의병리학회 2002년도 추계학술대회초록집
• /
• pp.144-144
• /
• 2002

Muscular lesion was detected in a 23-month-old castrated bull encountered at Kyungsan slaughter house. The lesion appeared as fat intervening muscle fibers. The affected animal had no clinical signs. On microscopic examination, there was replacement of many muscle fibers by normal fat cells. Numerous fat cells were located between muscle fibers. Remaining skeletal muscle cells were in degenerative process, and thus abnormal skeletal muscle cells had loose fibers while normal had intact ones. The advent of inflammatory cells is not at the lesion, which is unique view in steatosis.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권3호
• /
• pp.327-334
• /
• 2018

Objective: The objective of the present study was to validate genes and genomic regions associated with carcass weight using a low-density single nucleotide polymorphism (SNP) Chip in Hanwoo cattle breed. Methods: Commercial Hanwoo steers (n = 220) were genotyped with 20K GeneSeek genomic profiler BeadChip. After applying the quality control of criteria of a call rate ${\geq}90%$ and minor allele frequency (MAF) ${\geq}0.01$, a total of 15,235 autosomal SNPs were left for genome-wide association (GWA) analysis. The GWA tests were performed using single-locus mixed linear model. Age at slaughter was fitted as fixed effect and sire included as a covariate. The level of genome-wide significance was set at $3.28{\times}10^{-6}$ (0.05/15,235), corresponding to Bonferroni correction for 15,235 multiple independent tests. Results: By employing EMMAX approach which is based on a mixed linear model and accounts for population stratification and relatedness, we identified 17 and 16 loci significantly (p<0.001) associated with carcass weight for the additive and dominant models, respectively. The second most significant (p = 0.000049) SNP (ARS-BFGL-NGS-28234) on bovine chromosome 4 (BTA4) at 21 Mb had an allele substitution effect of 43.45 kg. Some of the identified regions on BTA2, 6, 14, 22, and 24 were previously reported to be associated with quantitative trait loci for carcass weight in several beef cattle breeds. Conclusion: This is the first genome-wide association study using SNP chips on commercial Hanwoo steers, and some of the loci newly identified in this study may help to better DNA markers that determine increased beef production in commercial Hanwoo cattle. Further studies using a larger sample size will allow confirmation of the candidates identified in this study.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권7호
• /
• pp.1057-1067
• /
• 2020

Objective: This study evaluated the effect of pedigree errors (PEs) on the accuracy of estimated breeding value (EBV) and genetic gain for carcass traits in Korean Hanwoo cattle. Methods: The raw data set was based on the pedigree records of Korean Hanwoo cattle. The animals' information was obtained using Hanwoo registration records from Korean animal improvement association database. The record comprised of 46,704 animals, where the number of the sires used was 1,298 and the dams were 38,366 animals. The traits considered were carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), and marbling score (MS). Errors were introduced in the pedigree dataset through randomly assigning sires to all progenies. The error rates substituted were 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, and 80%, respectively. A simulation was performed to produce a population of 1,650 animals from the pedigree data. A restricted maximum likelihood based animal model was applied to estimate the EBV, accuracy of the EBV, expected genetic gain, variance components, and heritability (h²) estimates for carcass traits. Correlation of the simulated data under PEs was also estimated using Pearson's method. Results: The results showed that the carcass traits per slaughter year were not consistent. The average CWT, EMA, BFT, and MS were 342.60 kg, 78.76 ㎠, 8.63 mm, and 3.31, respectively. When errors were introduced in the pedigree, the accuracy of EBV, genetic gain and h² of carcass traits was reduced in this study. In addition, the correlation of the simulation was slightly affected under PEs. Conclusion: This study reveals the effect of PEs on the accuracy of EBV and genetic parameters for carcass traits, which provides valuable information for further study in Korean Hanwoo cattle.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권10호
• /
• pp.1440-1444
• /
• 2005

To determine the effects of short-term dietary supplementation of branched-chain amino acids (BCAAs) during nursing (from 3 to 28 days of age) on plasma BCAA levels and subsequent growths in cattle, 12 nursing male Holstein calves, randomly assigned to control and treatment groups (n = 6 in each group), orally received a daily supplement of essential BCAAs (2 g/kg body weight/day; 1:1:1 of valine, leucine and isoleucine) or not. The plasma BCAA levels increased linearly after the administration. During the treatment period, average daily gain (ADG) was lower in the treatment group (0.43${\pm}$0.07 kg/day) than the controls (0.71${\pm}$0.07 kg/day, p<0.05). However, at 2 months of age, ADG was significantly higher in the BCAA-treated group (1.16${\pm}$0.26 kg/day vs. 0.51${\pm}$0.06 kg/day, p<0.05). Furthermore, at age 8, 9 and 10 month, ADG in the treated group (1.35${\pm}$0.23, 1.46${\pm}$0.07 and 1.60${\pm}$0.16 kg/day, respectively) showed a linear increase and was significantly higher than that in the control group (0.88${\pm}$0.14, 0.70${\pm}$0.21 and 1.11${\pm}$0.11 kg/kg, respectively, p<0.05). Overall, ADG was 15.6% higher in the treatment group (1.26${\pm}$0.05 kg vs. 1.09${\pm}$0.04 kg; p<0.05). The final body weight at slaughter was 14.8% higher in the treatment group (759.5${\pm}$17.7 kg vs. 661.7${\pm}$21.2 kg, p<0.01). Thus, the supplementation of BCAAs during nursing improves ADG and carcass weight in cattle and is a useful husbandry technique for beef cattle.

• Journal of Animal Science and Technology
• /
• 제58권1호
• /
• pp.3.1-3.6
• /
• 2016

Background: Uncoupling proteins 2 (UCP2) plays an important role in energy regulation, previous studies suggested that UCP2 is an excellent candidate gene for human obesity and growth-related traits in cattle and chicks. The current study was designed to detect the genetic variation of UCP2 gene, and to explore the association between polymorphism of UCP2 gene and growth, carcass and meat quality traits in rabbits. Results: A synonymous mutation in exon 1 and four variants in the first intron of the UCP2 gene were identified by using PCR-sequencing. The synonymous mutation c.72G>A was subsequently genotyped by MassArray system (Sequenom iPLEXassay) in 248 samples from three meat rabbit breeds (94 Ira rabbits, 83 Champagne rabbits, and 71 Tianfu black rabbits). Association analysis suggested that the individuals with AA and AG genotypes showed greater 70 d body weight (P < 0.05), 84 d body weight (P < 0.01), ADG from 28 to 84 days of age (P < 0.05), eviscerated weight (P < 0.01), semi-eviscerated weight (P < 0.01) and semi-eviscerated slaughter percentage (P < 0.05), respectively. Additionally, the individuals with AA and AG genotype had a lower pH value of longissimus muscle (P < 0.01) and hind leg muscle (P < 0.05) after slaughter 24 h. Conclusions: These findings indicated that UCP2 could be a candidate gene that associated with growth performance, body composition and meat quality in rabbits, and this would contribute to advancements in meat rabbit breeding practice.

• Journal of Preventive Medicine and Public Health
• /
• 제50권3호
• /
• pp.195-200
• /
• 2017

Objectives: Q fever is a zoonotic disease that occurs worldwide; however, little is known about its prevalence in South Korea. We attempted to determine the prevalence of Q fever seroreactivity among Korean slaughterhouse workers and the risk factors for seroreactivity according to the type of work. Methods: The study was conducted among 1503 workers at a total of 73 slaughterhouses and 62 residual-product disposal plants. During the study period, sites were visited and surveys were administered to employees involved in slaughterhouse work, and serological tests were performed on blood samples by indirect immunofluorescence assays. Serological samples were grouped by job classification into those of slaughter workers, residual-product handlers, inspectors and inspection assistants, and grading testers and testing assistants. Employee risk factors were analyzed according to the type of work. Results: Out of 1481 study subjects who provided a blood sample, 151 (10.2%) showed reactive antibodies. When these results were analyzed in accordance with the type of work, the result of slaughter workers (11.3%) was similar to the result of residual-product handlers (11.4%), and the result of inspectors and assistants (5.3%) was similar to the result of grading testers and assistants (5.4%). Among those who answered in the affirmative to the survey question, "Has there been frequent contact between cattle blood and your mouth while working?" the proportions were 13.4 and 4.6%, respectively, and this was identified as a risk factor that significantly varied between job categories among slaughterhouse workers. Conclusions: This study found a Q fever seroreactivity rate of 10.2% for slaughterhouse workers, who are known to be a high-risk population. Contact with cattle blood around the mouth while working was the differential risk factor between job categories among slaughterhouse workers.