• Asian-Australasian Journal of Animal Sciences
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• v.6 no.2
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• pp.219-223
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• 1993

A total of 333 calves were evaluated for carcass quality traits including: dressing percentage (DP), yield grade (YG), marbling score (MS), fat thickness (FT) and percent body fat (PF). Mating types included straightbred Angus (A) and Santa Gertrudis (S), the reciprocal crosses of these two breeds and Gelbvieh (G) ${\times}$ Angus. The year of birth, slaughter group and dam breed were found to have greatly influenced DP. Mating types had no effect on DP. For YG, sire breed, sire within sire breed and slaughter group were important. Crossbreds of A ${\times}$ S had the highest YG followed by A purebreds. Crossbreds of G ${\times}$ A had the lowest YG. Sire breed, dam breed and the slaughter group has significantly affected the MS. Sire breed, sire nested within sire breed and slaughter group were found to have greatly influenced the FT. Sires and dams of A produced the greatest FT while sires of G produced the lowest. Slaughter group 2 (slaughtered at 433 days of age) had a greater FT than group 1 (slaughtered at 393 days of age). For PF, sire breed, sire within sire breed, dam breed and slaughter group had significant effects. A purebreds had the largest PF while S purebreds and G ${\times}$ A crosses had the least.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.989-998
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• 2004

The objectives of this work was to investigate the effects of feeding type of concentrates during growing period and slaughter age on growth performance, feed efficiency and carcass characteristics in growing-fattening Holstein steers. Treatments were two concentrates feeding types(ad libitum or restricted 1.9% of BW) and three slaughter ages(at 19, 22 or 25 mo). Body weight at slaughter was numerically higher(approx. 8.3%) for the restricted than the ad libitum feeding groups. TDN intake rate was higher(8.4%) for the restricted than the ad libitum feeding groups. One mo slaughter delay increased TDN intake by 4%. Despite the lack of significances, higher back fat thickness and rib-eye area appeared in the restricted feeding or the late slaughter groups compared with the ad libitum feeding or the early slaughter groups. Marbling score(mean 2.46) numerically increased when the steers were restrictively fed concentrates compared with the ad libitum feeding groups. In addition, significant increases in the marbling score were associated with the slaughter age delay. In economic analysis, increases in total income were associated with the restricted feeding and the slaughter age delay. Whereas the highest monthly income appeared in the restricted feeding-and-slaughter at 22 mo group. In conclusion, the optimal feeding system may be 1) the restricted concentrates feeding(1.9% of BW) during growing period and 2) the late slaughter age(22${\sim}$25 mo of age) in growing-fattening Holstein steers fed rice straw.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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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.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.10
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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.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.731-744
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• 2005

Ninety Hanwoo steers(initial BW=167.2$\pm$13.4kg) were used to determine the effect of energy concentrations in concentrates and slaughter age on performance, carcass characteristics. Steers were allotted by BW to one of eighteen pens. Eighteen pens were randomly allotted to a low(70-70-71-72% for the growing, the early, the middle or the late fattening periods), medium(70-71-72-73%) or high(70-72- 73-74%) TDN level of concentrates. Five steers for each treatment of energy level were slaughtered every one month from 26 month of age to 31 month of age. Concentrates was fed restrictedly to achieve a predicted gain of 0.7-0.9kg from growing stage to middle fattening stage. All steers were fed orchard grass(Dactylis glomerata L.) hay as roughage during the growing period, fed rice straw gradually substituted for orchard grass hay during the early fattening period, and fed rice straw only thereafter. Overall body weight and feed intake were not affected by TDN levels of concentrates. Average daily gain for all treatments was higher than 0.9kg/d during the 19-21 month of age and decrease thereafter, but sustained above 0.7kg/d. Mean concentrates intake for all treatments was 1.0-1.3% of live BW during the growing period and 1.5% during the early fattening. Thereafter, it decreased up to 1.4% during the middle fattening and 1.0% during late fattening period. Delay of slaughter end point resulted in a gradual increase of rib-eye area, back fat thickness and marbling score, especially after slaughter age of 29 month there was significant increases(P<0.05). The appearance rate of 1+ and 1 grade related to the slaughter ages was 100% at 29, 30 and 31 months of age, whereas those at 26, 27 and 28 months were 93, 86 and 80%, respectively. Dressing rate was significantly(P<0.05) increased and rate of retailed cut weight significantly(P<0.05) decreased when slaughter age increased. In economic analysis, there was pronounced increase in net income up to 32-46% after slaughter age of 29 months. Under the conditions of this study, high TDN intake is not necessarily required for high quality Hanwoo meat production and slaughter age of 29 month might be the optimum for Hanwoo steers.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1080-1084
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• 2002

Carcass characteristics of 241 crossbred pigs (Korean wild boars ${\times}$ Landrace sows) were analyzed to examine variations in fasted body weight (FASTWT), carcass weight (CARCWT), dressing percentage (DP), back fat thickness (BFT) and longissimus muscle weight (LMW), and to estimate genetic and phenotypic parameters using three different slaughter-end points. Covariates in the least squares full sib model were slaughter age, fasted body weight and back fat thickness of the carcass. Coefficient of variation was highest for BFT followed by LMW, CARCWT, FASTWT and DP in magnitude. Regressions of three covariates on traits were all linear. However, slaughter age was not significant as a linear covariate for five traits while FASTWT was significant for CARCWT and LMW and BFT was significant for all remaining traits. Genetic and phenotypic variation was considerably reduced by regressing FASTWT or BFT in the model. Heritability estimates of FASTWT, CARCWT, DP and BFT were 0.68, 0.61, 0.11 and 0.49, respectively, using slaughter age as covariate (model 1). Those of CARCWT, DP, BFT and LMW were 0.15, 0.15, 0.30 and 0.11, respectively, using FASTWT as covariate (model 2). Heritability estimates of the traits using LMW as covariate (model 3) were similar to the estimates from Model 1 except that the estimate of CARCWT was reduced to 0.39. Genetic or phenotypic correlations among FASTWT, CARCWT and BFT were all positive and moderate to high. Those between BFT and LMW were also positive and low to moderate. However, genetic and phenotypic correlations between DP and CARCWT were positive while those between DP and FASTWT were negative. It was suggested from this study that differences in carcass yield traits be determined using slaughter age or back fat thickness as slaughter-end point and carcass quality traits using fasted body weight as slaughter-end point.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.5
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• pp.717-725
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• 2014

The objective of the study was to determine the effects of animal related factors on bruising in slaughter cattle, creatine kinase (CK) and beef quality. Three hundred and twenty one cattle from three breeds (108 Bonsmara, 130 Beefmaster and 83 Brahman) were used in this study. The animals were grouped as follows: Group 1 (16 months old), Group 2 (18 months old) and Group 3 (24 months old). At exsanguinations, blood samples for CK determination were collected using disposable vacutainer tubes. Muscularis longissimus thoracis et lumborum (LTL) was collected 24 h after slaughter to determine the colour ($L^*$, $a^*$, and $b^*$) and ultimate pH ($pH_u$) of beef. Breed, sex and age had significant effects (p<0.05) on bruising score, CK levels and beef quality. Bonsmara breed had the highest (80%) bruising score percentage, CK ($705.3{\pm}80.57U/L$) and $pH_u$ ($6.3{\pm}0.05$) values while the Bonsmara had the highest $L^*$ ($24.8{\pm}0.78$) $a^*$ ($17.5{\pm}0.53$) and $b^*$ ($12.8{\pm}0.53$) values. Higher CK levels were also observed in winter compared to summer, spring and autumn respectively. Therefore, animal factors (sex, breed and animal age at slaughter) contribute to the development of bruises and have an effect on the levels of CK and meat quality. It was also concluded that there is no significant relationship between meat parameters (L,* $a^*$, and $b^*$) and CK levels.

• Food Science of Animal Resources
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• v.21 no.2
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• pp.142-148
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• 2001

Comparisons in physicochemical characteristics of longissimus muscle between the Korean native pig(KNP: 75kg of slaughter weight and 240 days of age) versus Landrace(110kg of slaughter weight and 180 days of age) are as below. Compared with Landrace, KNP had a greater drip loss resulting from a lower muscle pH and water holding capacity, greater L*(lightness), a*(redness) and b*(yellowness) values in muscle color, and a greater L* value and smaller a* and b* values in attached backfat color. Tenderness were greater in the Korean native pig. Moreover, KNP had a greater number of muscle fibers and a smaller diameter of the fiber when examined by scanning electron microscopy. In sum, the Korean native pig, compared with Landrace, had a greater redness in meat color, a greater whiteness in fat color; the lower WHC and greater tenderness of the former apparently resulted from the lower slaughter weight rather than from a species difference.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.424-431
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• 2007

The aim of this study was to determine the effects of short road transportation in an open truck during hot season on live weight shrink, physiological responses, and carcass and meat quality of Omani sheep at 6 and 12 months of age. Thirty-six male sheep, 18 of each age group, were used. Age groups were assigned randomly to transported and not-transported groups. The transported group was transported to the slaughterhouse the day of slaughter in an open truck covering a distance of approximately 100 km. The average temperature during transportation was $37^{\circ}C$. The not-transported group was kept in a lairage of a commercial slaughterhouse with ad libitum feed and water for 48 h prior to slaughter. Blood samples were collected from sheep before loading and prior to slaughter via jugular venipuncture to assess their physiological response to transport in relation to hormonal levels. Animals were weighed just before loading onto a truck and after transport to assess shrinkage. Muscle ultimate pH, expressed juice, cooking loss percentage, WB-shear force value, sarcomere length and colour L*, a*, b* were measured on samples from longissimus dorsi, biceps femoris and semitendinosus muscles collected at 24 h postmortem at $1-3^{\circ}C$. Live weight shrinkage losses were 1.09 and 1.52 kg for 6 and 12 month transported sheep, respectively. The transported sheep had significantly (p<0.05) higher cortisol, adrenaline, noradrenaline, and dopamine concentration levels prior to slaughter at both ages than the not-transported sheep. Transportation significantly influenced meat quality characteristics of three muscles. Muscle ultimate pH and shear force values were significantly higher, while CIE L*, a*, b*, expressed juice and cooking loss were lower in transported than not-transported sheep. Age had a significant effect on meat quality characteristics of Omani sheep. These results indicated that short-term pre-slaughter transport at high ambient temperatures can cause noticeable changes in physiological and muscle metabolism responses in sheep.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1364-1368
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• 2003

Effect of slaughter age (24, 28 and 38 months of age) on beef color stability during display of m. serratus ventralis, m. psoas major, m. semitendinosus and m. longissimus thoracis from Japanese Black steers was studied. Steak samples from muscles were over-wrapped with PVC film and displayed under fluorescent lights at $4^{\circ}C$ for 12 days. Percentages of metmyoglobin of steak samples were determined at days 0, 3, 6, 9 and 12. The percentage of metmyoglobin of m. psoas major at day 3 of display in the 24 months group was lower (p<0.05) than that in the 38 months group. The percentage of metmyoglobin of m. semitendinosus at day 6 of display in the 38 months group was higher (p<0.05) than that in the other groups. The percentage of metmyoglobin of m. longissimus thoracis at day 3 of display in the 24 months group was lower (p<0.01) than that in the other groups. The percentage of metmyoglobin of m. longissimus thoracis at day 6 (p<0.01), 9 (p<0.01) and 12 (p<0.05) of display in the 38 months group were higher than those in the other groups. Crude fat concentration in m. longissimus thoracis increased (p<0.05) after 28 months of age. $\alpha$-Tocopherol concentration in m. serratus ventralis in the 38 months group was higher (p<0.001) than that in the other groups. In m. psoas major the $\alpha$-tocopherol concentration in the 38 months group was higher (p<0.05) than that in the 24 months group. The $\alpha$-tocopherol concentration in m. longissimus thoracis increased (p<0.001) with age. These results suggested that in spite of increase in both the crude fat and the $\alpha$-tocopherol concentrations in m. longissimus thoracis, the beef color stability during display became short with age.