• Journal of Animal Science and Technology
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• 제64권1호
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• pp.143-154
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• 2022

This study was conducted to evaluate the relationship among market weight, slaughter age, yield grade, and primal cut yield in Hanwoo. A total of 403 Hanwoo (Korean native cattle) was assessed for carcass traits such as carcass cold weight, backfat thickness, ribeye area, dressing percentage, yield index, and marbling score. The production yield of the individual major primal cuts of Hanwoo beef was also measured. Carcass cold weight, ribeye area, and backfat thickness, which affect meat quality increased with increased market weight (p < 0.05). The production yield of the ten major primal cuts also increased with increased market weight (p < 0.05). In terms of slaughter age, carcass cold weight, ribeye area, and backfat thickness all increased from 25 months to 28-29 months, and the production yield of all prime cuts also increased with increasing slaughter age. According to the meat yield grade, carcass cold weight and backfat thickness increased from grade A to grade C, although the ribeye area was not affected. The combined findings of the study suggest that slaughtering Hanwoo at the weight of 651-700 kg and 701-750 and age of 28.23 and 29.83 months could be desirable to achieve the best quality and quantity grade of Hanwoo beef. However, the positive correlation of carcass cold weight and backfat thickness, and the negative correlation of the yield index according to primal cuts yield indicated that it is necessary to couple the slaughtering management of cattle with improved genetic and breeding method of Hanwoo to increase the production yield of the major prime cuts of Hanwoo beef.

• 한국축산식품학회지
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• 제33권3호
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• pp.305-316
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• 2013

The strategy for increasing the palatability of Hanwoo beef through fattening could lead to a decline in yield grade. The aim of this study was to examine the meat quality traits of Longissimus dorsi (LD) muscle from carcasses of Hanwoo steers at different yield grades. A total of 246 Hanwoo steers was divided into the following yield grades: A (n=77), B (n=76) and C (n=93). Meat quality traits, including proximate composition, cholesterol content, nucleotide content, dipeptide content, creatine and creatinine, free amino acid content, fatty acid composition, instrumental meat color, pH, water holding capacity, drip loss, cooking loss, and sensory qualities of the LD muscle from the 3 yield grades of Hanwoo carcasses were measured. The decline in yield grade from A to C resulted in an increase in crude fat and cholesterol content as well as a decrease in inosine 5'-monophosphate and aspartic acid in the LD muscle (p<0.05). In terms of fatty acid composition, the LD muscle from yield grade A had higher SFA and PUFA and lower MUFA content than that from yield grade C (p<0.05). However, the ratio of PUFA/SFA and n-6/n-3 did not differ among LD muscles from the 3 yield grades. There were no significant differences among other meat quality traits in relation to the yield grade. In conclusion, we suggest that the changes of substances related with health and flavor can be considered in order to obtain better quality Hanwoo beef.

• Journal of Animal Science and Technology
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• 제63권5호
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• pp.1064-1075
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• 2021

Recently, a high level of dietary crude protein (CP) has become of interest as a possible practice to improve the carcass quality of beef cattle, and its level has been increasing in the field. However, there is little scientific evidence that supports this. This study was conducted to test whether a high dietary CP level would improve growth performance, body metabolism, and carcass traits in Hanwoo beef cattle. A total of 32 Hanwoo finishing beef cattle (18 multiparous cows, six heifers, and eight steers) participated in a 12-weeks feeding trial. Two kinds of total mixed rations were prepared to contain two different CP; 156 g/kg for the control (CON) and 173 g/kg of CP for the treatment (HCP), while maintaining a similar level of metabolizable energy. The experiment was ended when more than half of the steers reached the target body weight (730 kg). Blood was collected at the end of the experiment. After harvesting, the carcass trait was evaluated at the slaughterhouse according to Korean standards. The carcass yield score and grade were also calculated based on revised criteria. Overall, dry matter intake, average daily gain, blood metabolites concentration, and the carcass traits, except for backfat thickness and the yield score, did not differ between the treatments. The HCP had lower backfat thickness than those of CON. There was no difference in the carcass yield grade, but the yield score was higher in the HCP treatment. According to the newly revised carcass grading criteria, both yield score and grade were higher in HCP than in CON. Increasing CP supply decreased the carcass's backfat thickness without altering growth performance and body metabolism, resulting in improved yield score and grade. Therefore, feeding a high CP diet may be beneficial in the farm income, although it may also increase feed cost and nitrogen excretion to the environment.

• 한국수정란이식학회지
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• 제23권4호
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• pp.291-298
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• 2008

We separately cultured follicular oocytes collected from individual ovaries of slaughtered Korean native cows and examined both the embryonic development rate and pregnancy rate after embryo transplantation according to the meat yield and quality grades of the source beef carcass. Oocytes from meat yield grade B cows exhibited a higher fertilization rate and embryonic developmental rate to the eight-cell stage than oocytes from grade A or C animals (p<0.05), but there was no significant difference in rate of development to the blastocyst stage among meat yield grades A, Band C. The oocyte cleavage rate and development rate to the eight-cell stage from meat quality grade 3 cattle was higher than grades 1++, 1+, 1 and 2 (p<0.05). Embryos derived from grade animals displayed a development rate to the blastocyst stage of 19.4%, which was also higher than all other meat quality grades (p<0.05). Transplantation of in vitro-cultured oocytes from meat yield grade A ovaries led to a higher pregnancy rate (64.2%) than in vitro-cultured oocytes from meat yield grade B ovaries (56.5%), but there was no significant difference between the two groups in pregnancy or abortion rates. In conclusion, embryonic development rate and pregnancy rate has a close relation to meat quality grades of the source beef carcass, this results is to give information for the Korean native cows improvement of breed.

• Asian-Australasian Journal of Animal Sciences
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• 제15권4호
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• pp.591-595
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• 2002

Three hundred thirty five progeny testing steers of Korean beef cattle were evaluated ultrasonically for back fat thickness (BFT), longissimus muscle area (LMA) and intramuscular fat (IF) before slaughter. Class measurements associated with the Korean yield grade and quality grade were also obtained. Residual standard deviation between ultrasonic estimates and carcass measurements of BFT, LMA were 1.49 mm and $0.96cm^2$. The linear correlation coefficients (p<0.01) between ultrasonic estimates and carcass measurements of BFT, LMA and IF were 0.75, 0.57 and 0.67, respectively. Results for improving predictions of yield grade by four methods-the Korean yield grade index equation, fat depth alone, regression and decision tree methods were 75.4%, 79.6%, 64.3% and 81.4%, respectively. We conclude that the decision tree method can easily predict yield grade and is also useful for increasing prediction accuracy rate.

• 한국축산식품학회지
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• 제28권5호
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• pp.604-609
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• 2008

한우도체의 육량등급요인인 도체중, 등지방두께 및 배장근단면적과 이들 요인으로 산정된 육량지수와 육량등급은 성 및 출하체중 별로 유의적인 차이가 있는 것으로 분석되었다. 본 연구에서 설정된 성별 도체의 소매 정육량 예측식은 적합도($R^2$)가 높아 유통현장에서 도체의 상품가치를 손상시키지 않고 신속하고 정확하며 저비용으로 소매 정육량을 예측하는데 유용하게 이용될 수 있으며 또한 국가에서는 소고기 수급계획 수립에 활용하고 브랜드한우단체 등에서는 직판장의 공급량 결정에 이용할 수 있겠다. 한우도체의 판매정육량을 좀더 정확하게 예측할 수 있는 추정식을 산출하기 위해서는 성별로 도체중, 등지방두께 및 배장근면적과 같은 측정요인이 출하체중 증가에 따라 균일하게 발현되도록 효과적인 개량과 사양관리가 선결되어야 하겠다.

• Journal of Animal Science and Technology
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• 제45권1호
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• pp.151-156
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• 2003

국내에 생우로 수입된 호주산 육우 Hereford, Angus, Murray Grey, Hereford${\times}$Angus 각각 10두의 도체등급 특성을 비교 분석하여 수입생우의 국내 비육에 대한 기초자료를 제시하고자 실시하였다. 육량등급요인 중 등지방 두께는 Hereford종이 13.7mm로 가장 얇았으며, Angus, Murray Grey, Hereford${\times}$Angus은 각각 18.20, 18.90, 17.30mm로 나타났다(p<0.05). 배최장근 단면적에서는 품종간 유의적인 차이가 나타나지 않았으며(p>0.05), 육량지수는 Hereford종이 64.63으로 가장 높았고, Murray Grey종이 62.43으로 가장 낮았다(p<0.05). 육질등급요인 중 육색은 다른 품종들에 비하여 Hereford종이 낮았으며, 지방색은 Angus종이 가장 높았다(p<0.05). 성숙도는 다른 품종에 비하여 Angus종이 가장 낮았으며(p<0.05), 근내지방도, 조직감에서는 품종간에 차이가 없었다. 품종별 근내지방도 등급 출현율은 Angus종이 근내지방도 1++등급 이상이 50%를 차지하여 가장 높았으며, Hereford종이 전두수 1++등급 미만으로 가장 낮게 나타났다. 품종별 최종 도체등급 출현율에 있어서 육질등급에서는 Angus종이 육질 2등급 출현율이 20%로 가장 좋았으며, Hereford종과 교잡종(Hereford$\times$Angus)은 100% 육질 3등급으로 가장 저조한 성적을 보였다. 육량등급 출현율에 있어서는 Hereford종이 육량 B등급 출현율 30 %로 가장 좋은 성적을 보였으나, Angus종과교잡종(Hereford${\times}$Angus)은 100% 육량 C등급으로 가장 저조한 성적을 보였다. 전체적으로 볼 때 교잡종은 전 두수 육질 3등급, 육량 C등급을 보여 육질 및 육량 면에서 가장 저조하였다. 본 연구결과 수입생우(거세우)는 한우거세우에 비하여 육량, 육질 모든 면에서 저조한 결과를 보였다. 그러나 비육시험에서 한우와 동일하게 시험을 하지 못한 면에서는 아쉬운 점이 있었으며, 한우거세우와 정확한 비교를 위해서는 동일조건에서 한우와 수입생우의 비교시험이 필요하다고 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권1호
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• pp.123-135
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• 2001

Application of growth promoters by means of implantation or supplementation to the diets has been routine in the beef cattle industry of many countries for the better performance in growth and improvement of feed efficiency. Anabolic implants (zeranol, trenbolone acetate, and estradiol with testosterone or progesterone) have generated various positive effects. Zeranol implantation, in general, improved average daily gain (ADG), feed conversion (FC), dressing percentage (DP) and yield grade (YG) of cattle, and increased dry matter intake (DMI). Trenbolone acetate with or without estradiol also increased mean values of ADG and loin eye area (LEA) but reduced DMI and improved FC of cattle. Estradiol with testosterone or progesterone increased ADG and DMI. Anabolic implants, however, had minimal or negative effects on marbling or quality grade. The magnitude of the response to these anabolic implants in performance of beef cattle has varied depending on the type of implants, amount and duration of exposure, age of animals and combination of implants. Administration of bovine somatotropin improved ADG and FC, and decreased fat deposition. Ionophores improved FC in cattle from reduced DMI without great response to ADG. Supplementation of monensin and lasalocid reduced molar proportion of propionate. Monensin and lysocellin increased apparent absorption and retention of some minerals in cattle. Despite the improved cattle performance in growth and FC, results in beef quality from the application of the growth promoters appeared to vary or in conflict under a variety of environmental conditions.

• Journal of Animal Science and Technology
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• 제59권3호
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• pp.6.1-6.6
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• 2017

Background: This study was aim to observe the effects of feeding mixed local hay (MH) consisted of 55% orchard grass (Dactylis glomerata L.), 35% tall fescue (Festuca arundinacea) and 10% red clover (Trifolium pratense) to Hanwoo steers on performance, carcass characteristics and meat quality (longissimus thoracis) compared with feeding imported timothy hay (TH) and local rice straw (RS). Results: Although no significant effects were found on animal performance and carcass yield grade, the carcasses of MH group had higher marbling score and quality grade than those of RS and TH group (P < 0.05). Therefore, higher fat content (P < 0.001), lower shear force and hardness value in the beef of MH group than that of other groups were observed. Furthermore, the beef of MH group had higher CIE $a^*$ value (redness) than that of other groups and feeding MH to Hanwoo steers lowered n-6 to n-3 fatty acids ratio in beef. Conclusions: Mixed hay provided benefits on meat quality and could be used for Hanwoo fattening program.

• 한국축산식품학회지
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• 제30권6호
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• pp.905-909
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• 2010

Two sets of data on carcass traits and beef cut parameters were used to investigate the relationships between carcass and beef cut measurements, which can be used to make predictions of retail cut percentages. One set had a total of 1,141 measurements of Hanwoo cattle of three different sex origins, which were slaughtered in an abattoir located at the National Institute of Animal Science, RDA, Korea from 1996 to 2008. To develop prediction models for retail cut percentage with higher accuracies than the current model, another set consisting of a total of 13,389 records of carcass and beef cut traits were collected from 30 abattoirs and butcheries in Korea from 2008 to 2009. Bulls yielded heavier and leaner carcasses than steers. High correlation coefficients were estimated between amount of body fat and percent retail cut (-0.82) as well as between back fat thickness (BF) and percent retail cut (-0.62). The amount of retail cut, however, was highly correlated with body weight before slaughter (BW, 0.95) or with cold carcass weight (CWT, 0.94). Relationships between percent retail cut and measurable beef yield traits, BF, loin eye area (LEA) or CWT varied by sex class, which must be considered for development of a prediction model with high accuracy. Models of data for all breeds and sexes fit the effects of breed, sex, and interaction of abattoir by butchers, whereas models of data for each breed and sex fit the effect of interaction of abattoir by butcher only. Due to possible future changes in back fat control, we performed a log transformation of BF. Our new models fit better than the currently used model.