• Journal of Animal Science and Technology
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• 제54권6호
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• pp.443-448
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• 2012

This study was conducted to investigate changes of blood metabolites and enzyme activities at different slaughter ages of Hanwoo cattle. Blood samples were taken from six hundred thirty two steers (24~33 months of age) and one hundred twenty eight bulls (17~24 months of age) by venipuncture from caudal vein immediately prior to slaughter. Glucose concentrations were linearly increased (P<0.001) with increases of the slaughter age in steers, and blood urea nitrogen (BUN) concentrations were linearly decreased (P<0.001) with increases of the slaughter age in steers. Likewise, glucose and albumin concentrations in bulls were linearly decreased (P=0.009 and P<0.001, respectively) with increases of the slaughter age. BUN, cholesterol, triglycerides, and total cholesterol concentrations were linearly increased (P<0.001, 0.018 and 0.002, respectively), and creatinine concentrations were quadratically increased (P=0.009) with increases of the slaughter age. Activity of gamma glutamyltransferase (${\gamma}$-GT) and aspartate aminotransferase (AST) was linearly increased (P<0.001) with increases of the slaughter age in both steers and bulls, whereas alanine aminotransferase (ALT) was not affected by increasing slaughter age. In addition, the concentrations of ${\gamma}$-GT and AST were higher (P<0.05) for bulls than those of steers at 24 months of age. Increased levels of ${\gamma}$-GT and AST indicate impaired liver function; it may be associated with increases of concentrate level which is a concomitant of the extended fattening periods in Hanwoo feeding. In conclusion, the results in the present study may be one of the useful information for diagnosis of the metabolic disorder in Hanwoo cattle.

• 한국축산식품학회지
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• 제42권3호
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• pp.455-466
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• 2022

The aim of this study was to assess the occurrence of white striping (WS), wooden breast (WB), and WS combined with WS/WB muscle abnormalities in broilers (Ross 500) at different slaughter ages (34, 41, and 48 d). In addition, the influence of these muscle abnormalities at different slaughter ages on quality characteristics (physical dimensions, pH, color index, and chemical composition) was studied. Overall occurrence of muscle abnormalities was 45%, 92%, and 100% at slaughter ages of 34, 41, and 48 d, respectively. It was found that about 39% from the occurrence of muscle abnormalities was not similar in the same bird (left and right fillets). Breast fillets affected by muscle abnormalities had significantly (p<0.05) higher weight than normal fillets. At slaughter age of 34 d, normal fillets had significantly higher L^* (67.37 vs. 61.73 and 63.05, p<0.05), lower a^* (3.25 vs. 4.87 and 5.18, p<0.05) and b^* (4.02 vs. 5.20 and 5.99, p<0.05) than WS and WS combined with WB fillets; respectively. The changes in chemical composition due to muscle abnormalities were more significant at high slaughter age than at low slaughter age. In conclusion, the occurrence of muscle abnormalities was strongly influenced by slaughter age. Moreover, breast fillets affected by muscle abnormalities had different quality characteristics (proximate composition, color traits, and dimensions) in comparison to normal fillets.

• Journal of Animal Science and Technology
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• 제55권4호
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• pp.315-323
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• 2013

This study analyzed optimal slaughter ages and carcass traits to investigate factors that affect farm incomes. Carcass characteristics and economical analysis of 81 Hanwoo steers previously tested (Expt. 1) and 5,826 steers from Gangwon-Do, area A (Expt. 2) were used. In Expt. 1, the strongest relationship was between the slaughter age and the carcass weight based on the $R^2$ value, and the weakest relationship was between the slaughter age and the marbling score based on the $R^2$. The slaughter age, marbling score, and rib-eye area of steers slaughtered from 26 to 31 months of age had a positive effect on income, but back fat thickness had a negative effect. In the economical analysis of Expt. 1, the optimal time for slaughter was 31 months of age. In Expt. 2, composed of steers slaughtered from 26 to 35 months of age in farms site of area A, the income was highest from steers slaughtered at 28 months of age, after which the income decreased. From the results of Expt. 1 and 2, it is evident that the optimal slaughter age of Hanwoo steers is affected by the genetic differences of calves, the feeding program and management, fattening skills, or carcass price. In order to improve the income of individual farms, the slaughter age must be precisely decided by understanding the exact relationship between the feeding cost of Hanwoo steers and slaughter results, such as carcass weight, yield grade and quality grade.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.605-610
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• 2006

The objective of the present experiment was to determine the effects of slaughtering at different ages and the use of a commercial probiotic (115-Biogallinox) in broiler diets on the color properties of carcasses, during the first 24 h following slaughter. Ross 308 male broiler chickens obtained from a commercial hatchery were raised to either 35 or 42 days of age. Chickens were fed with different levels of probiotic ($P_0$: 0.0%, $P_1$: 0.1% and $P_2$: 0.2%) containing Saccharomyces cerevisiae during the experimental period. At the end of the trial all birds were slaughtered and then stored at $3^{\circ}C$ for 24 h. The pH and skin colour of carcasses were determined 1, 3, 7, 10, 13, 17 and 24 h after slaughter. Although the use of probiotic and post-mortem ageing time affected the pH (p<0.01), it was not affected by slaughter age (35 and 42 days) (p>0.05). The highest pH values occurred in carcasses of broilers fed 0.2% probiotic. The pH values of carcasses decreased with post-mortem ageing time (p<0.01). Main factors (treatment, slaughter age and post-mortem ageing time) had an effect on colour ($L^*$, $a^*$ and $b^*$) values (p<0.01). $L^*$ values of 42d-old slaughter and $P_2$ group were lower than those of 35d-old slaughter and other probiotic groups. The $a^*$ and $b^*$ values of 35d-old slaughter were lower than those of 42d-old slauhgter. The $a^*$ and $b^*$ values increased during post-mortem ageing (p<0.01). It was determined that changing of the colour traits of broiler carcasses was correlated with probiotic, pH and post-mortem ageing time. Also, it was observed that darkness of carcass colour increased as time progressed.

• Asian-Australasian Journal of Animal Sciences
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• 제21권9호
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• pp.1227-1232
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• 2008

Carcass characteristics data of Hanwoo (N = 1,084) were collected from two stations of the National Livestock Institute of Animal Science (NIAS), Korea and records from thirteen individual cow-calf operators were analyzed to estimate variance and covariance components and the effect of different slaughter endpoints. Carcass traits analyzed were cold carcass weight (CWT, kg), REA (rib eye area, cm2), back fat thickness (mm) and marbling score (1-7). Four different models were examined. All models included sex and contemporary group as fixed effects and the animal's direct genetic potential and environment as random effects. The first model fitted a linear covariate of age at slaughter. The second model fitted both linear and quadratic covariates of age at slaughter. The third model fitted a linear covariate of body weight at slaughter. The fourth model fitted both linear covariates of age at slaughter and body weight at slaughter. Variance components were estimated using the REML procedure with Gibb's sampler. Heritability estimate of CWT was in the range of 0.08-0.11 depending on the model applied. Heritability estimates of BF, REA and MS were in the ranges of 0.23-0.28, 0.19-0.26, and 0.44-0.45, respectively. Genetic correlations between CWT and BF, between CWT and REA, and between CWT and MS were in the ranges of -0.33 - -0.14, 0.73-0.84, and -0.01- 0.11, respectively. Genetic correlations between REA and BF, between MS and BF and between REA and MS were in the ranges of -0.82 ~ -0.72, 0.04~0.28 and -0.08 ~ -0.02, respectively. Variance and covariance components estimated varied by model with different slaughter endpoints. Body weight endpoint was more effective for direct selection in favor of yield traits and body weight endpoints affected more of the correlated response to selection for the traits of yield and quality of edible portion of beef.

• 한국축산식품학회지
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• 제29권5호
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• pp.550-556
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• 2009

Two experiments were carried out to investigate the relationship of slaughter age and carcass traits of Hanwoo cattle. A total number of 11,284 heads of cattle (4,624 bulls, 6,120 steers, and 540 females) were used in the experiment (Exp.) 1. In the Exp. 2, 3,887 heads of steers slaughtered at age of 24-36 mon were used. After 24 h post-slaughter chilling, the carcasses were weighed and evaluated by an official grader of carcass traits according to the Korean carcass grading standard. Backfat thickness was the main variable in yield index and grade whereas marbling score was the main variable in carcass quality grade. Meat color was an important factor affecting carcass quality grade of bulls; fat color was an important factor affecting those of steers and females; and maturity was an important factor affecting that of females. After 24-mon-old, extension of slaughter age did not automatically increase the quantity and quality of meat. However, 29 mon of age can be regarded as the optimum time to slaughter steers to attain the highest take home money for farmers.

• 농업생명과학연구
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• 제45권6호
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• pp.109-114
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• 2011

본 논문은 한우 거세우의 각 월령별 체중과 18개월 체척, 도체형질에 대하여 출생지, 후대검정차수, 측정일령, 도축일, 도축일령등의 환경효과가 영향을 미치는지 알아 보기위하여 실시하였다. 이 연구에 사용된 자료는 농협중앙회 한우개량사업소에서 2004년부터 2008년까지 후대 검정한 38차에서 47차까지의 거 세우 1,838두의 성장형질과 도체형질 자료를 이용하였고, 성장형질은 18개월령 체척자료와 6개월, 12개월, 18개월, 24개월 체중을, 도체형질은 24개월령 도축성적을 이용하였다. 각 형질에 대한 환경효과 분석을 위해 각 월령별 체중에 대해서는 고정효과를 출생지, 후대검정차수로 하였고 공변량을 측정일령으로 하였다. 도체형질은 도축일을 고정효과로 도축일령을 공변량으로 하였다. 18개월 체척의 경우는 고정효과를 출생지, 후대검정차수로 하였고, 공변량을 18개월 체척측정일령으로 하였다. 분석결과 24개월 체중에서는 출생지 효과가 유의성이 낮은 것으로 나타났다. 도체형질인 도체중, 등심단면적, 육량지수, 등지방 두께는 도축일에 따른 유의적인 차이가 존재하는 것으로 나타났지만 도축일령에 따른 유의적인 차이는 없었다. 근내지방도에 대해서는 도축일령과 도축일 모두 영향을 미치는 것으로 나타났다. 또한 체척형질은 흉심, 고장폭, 흉위에서 출생지 효과는 영향이 없는 것으로 나타났다. 따라서 본 연구결과는 한우 유전평가 모형 설정 시 활용 가능한 것으로 예상된다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권12호
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• pp.1645-1656
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• 2010

This study was conducted to investigate the effects of strain on broiler performance, and age at slaughter and postchilling (PC) aging time on meat quality traits. A total of 500 one-day-old chicks (250 Hubbard classic and 250 Lohman) were reared under commercial conditions. Half of the broiler birds from each strain were slaughtered at 32 days and the other half at 42 days old. At each processing day, 168 carcasses were randomly selected (84 Hubbard and 84 Lohman) and divided into groups of 28 carcasses within each strain, and aged for 0, 4 and 24 h after chilling. Average weekly body weight was comparable between strains. Feed conversion ratio was higher (p<0.05) for the Hubbard strain during the second and third week of age. Initial carcass pH was significantly (p<0.05) affected by age where younger birds (32-d-old) had lower pH values than older (41-d-old) birds. Breast temperature was higher (p<0.001) for Lohman than Hubbard at 0, 2 and 4 h of PC. Younger birds had a lower breast temperature (p<0.001) at all measured times of PC. Thaw loss, cook loss and water holding capacity were not significantly affected by strain, age or aging time. Lohman strain had more tender meat (p<0.05) than Hubbard strain, and tenderness was improved with the increase of broiler age and aging time. Meats from Hubbard were lighter and less red than those from Lohman strain where younger birds had darker color. In conclusion, strain, age at slaughter and PC aging duration are critical to breast meat quality characteristics, and 4 h of aging are required before deboning in order to obtain more tender fillets.

• Journal of Animal Science and Technology
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• 제55권5호
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• pp.405-416
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• 2013

본 연구는 도체월령별 도체형질의 변화를 분석하여 적정 도축시기를 결정하는 데 필요한 정보를 얻기 위한 목적으로 실시하였으며, 2005년 10월부터 2011년 9월 사이에 도축된 거세우 17,249두의 도체형질자료를 이용하였다. 각 도체형질의 평균과 표준편차는 도축일령, 도체중, 등지방두께, 등심면적, 근내지방도, 육량지수, 도체단가 및 도체 총가격에서 각각 $940.4{\pm}73.00$, $437.0{\pm}48.70$ kg, $12.1{\pm}4.32$ mm, $90.3{\pm}9.51cm^2$, $5.7{\pm}1.86$, $65.13{\pm}3.23$, $14.150{\pm}1.77$천원 및 $6181.18{\pm}1009.46$천 원으로 나타났다. 도체월령별 회귀계수에서 조기 도축그룹에서는 도체 단가를 제외한 전체 형질들에서, 만기 도축그룹에서는 근내지방도를 제외한 전체 형질들에서 월령별 회귀계수가 유의성이 인정되었다. 수익을 얻기 위해서는 28개월령 이전으로 도축시기를 결정해야 할 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권10호
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• pp.1496-1503
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• 2013

The objective of this study was to determine the effect of municipal abattoir conditions and animal factors on avoidance-related behaviour (AB) of sheep at slaughter, bleeding times (BT) and mutton quality. The behaviour of 66 castrates and 19 ewes of different age categories was observed at three stages of slaughter. Higher behaviour scores indicated higher levels of AB. Time intervals between the start of blood flow and the time the flow changed from a constant stream into drips were recorded as BT. Thirty two meat samples were obtained to measure quality variables. These were colour ($L^*$, $a^*$ and $b^*$), $pH_{24}$, temperature, cooking loss (CL) and tenderness. Correlations were determined between BT and meat quality variables. Animal behaviour at slaughter differed with breed, gender and age group. Avoidance behaviour was higher in the Dorper breed than in both the Merino breed and their crosses. It was also higher in younger (<10 months) lambs than in older sheep. Castrates were more aggressive or in panic than ewes. Castrates had longer ($72.6{\pm}0.53s$) BT than the ewes ($63.6{\pm}2.82s$). Ewes had higher CL ($39.8{\pm}1.04%$) values than castrates ($35.1{\pm}0.95%$). Meat from castrates was tougher ($32.6{\pm}1.95N$) than the meat from ewes ($24.3{\pm}1.16N$). There were no significant correlations obtained between BT and meat quality variables. It can therefore be concluded that abattoir conditions, breed, age and gender had an effect on AB at slaughter. Gender had an effect on BT and mutton quality.