• Journal of Animal Science and Technology
• /
• v.54 no.6
• /
• pp.443-448
• /
• 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.

• Food Science of Animal Resources
• /
• v.42 no.3
• /
• pp.455-466
• /
• 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
• /
• v.55 no.4
• /
• pp.315-323
• /
• 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
• /
• v.19 no.4
• /
• pp.605-610
• /
• 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
• /
• v.21 no.9
• /
• pp.1227-1232
• /
• 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.

• Food Science of Animal Resources
• /
• v.29 no.5
• /
• pp.550-556
• /
• 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.

• Journal of agriculture & life science
• /
• v.45 no.6
• /
• pp.109-114
• /
• 2011

The objective of this study was to investigate the effects of environments (farms born, testing groups, age at the tests, date at slaughter, ages at slaughter) on body weights at 6, 12, 18 and 24 months of ages, body type measurements at 18 months of age and carcass characteristics in Hanwoo steer populations that were collected from commercial farms and reared in a progeny testing station. Performances of a total of 1,838 steer calves set for tests from 2004 to 2008 were recorded. Carcass characteristics were the carcass grading results evaluated and data collected slaughter scores at 24 months of age. For growth traits of all age classes and body type traits measured at 18 months of age, farms born, test group and linear covariate of age at test were fit in the models. For carcass traits, date at slaughter and linear covariate of ages at slaughter were fit in the models. Effect of farm at birth was not significant for body weight at 24 months of age. Carcass weight, eye muscle area, yield score and back fat thickness were affected by dates at slaughter but not by the ages at slaughter. Marbling score, however, was affected by these two effects. Farms at birth did not seem to affect body type measures greatly. This study will be utilized for Hanwoo Steers genetic evaluation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.12
• /
• pp.1645-1656
• /
• 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
• /
• v.55 no.5
• /
• pp.405-416
• /
• 2013

This aim of this study was to estimate the most reasonable slaughter month for Hanwoo steers according to carcass traits. Carcass trait data on Hanwoo steers (17,249 head) were collected from October 2008 to September 2011. To measure the regression coefficients, Hanwoo steers were divided into two groups according to slaughter age: early (25 to 31 months) and late (32 to 38 months) groups. Regression coefficients of carcass traits according to slaughter age were significantly different (p<0.001) with the exception of PPKG (estimated auction price per 1 kg of carcass weight) in the early slaughter age group and MAR (marbling score, p<0.05) and PPKG (p<0.05) in the late slaughter age group. To obtain a positive gross margin, Hanwoo should be slaughtered at around 28 months of age.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.10
• /
• pp.1496-1503
• /
• 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.