• Asian-Australasian Journal of Animal Sciences
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• 제32권5호
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• pp.701-710
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• 2019

Objective: This study investigated the effect of different acute heat stress (HS) levels on chicken meat quality and ultra-structure. Methods: Chickens were randomly divided into 7 groups to receive different HS treatments: i) $36^{\circ}C$ for 1 h, ii) $36^{\circ}C$ for 2 h, iii) $38^{\circ}C$ for 1 h, iv) $38^{\circ}C$ for 2 h, v) $40^{\circ}C$ for 1 h, vi) $40^{\circ}C$ for 2 h, and vii) un-stressed control group ($25^{\circ}C$). Blood cortisol level, breasts initial temperature, color, pH, water holding capacity (WHC), protein solubility and ultra-structure were analyzed. Results: HS temperatures had significant effects on breast meat temperature, lightness ($L^*$), redness ($a^*$), cooking loss and protein solubility (p<0.05). The HS at $36^{\circ}C$ increased $L^*{_{24h}}$ value (p<0.01) and increased the cooking loss (p<0.05), but decreased $a^*{_{24h}}$ value (p<0.05). However, as the temperature increased to $38^{\circ}C$ and $40^{\circ}C$, all the values of $L^*{_{24h}}$, cooking loss and protein denaturation level decreased, and the differences disappeared compared to control group (p>0.05). Only the ultimate $pH_{24h}$ at $40^{\circ}C$ decreased compared to the control group (p<0.01). The pH in $36^{\circ}C$ group declined greater than other heat-stressed group in the first hour postmortem, which contributed breast muscle protein degeneration combining with high body temperature, and these variations reflected on poor meat quality parameters. The muscle fiber integrity level in group $40^{\circ}C$ was much better than those in $36^{\circ}C$ with the denatured position mainly focused on the interval of muscle fibers which probably contributes WHC and light reflection. Conclusion: HS at higher temperature (above $38^{\circ}C$) before slaughter did not always lead to more pale and lower WHC breast meat. Breast meat quality parameters had a regression trend as HS temperature raised from $36^{\circ}C$. The interval of muscle fibers at 24 h postmortem and greater pH decline rate with high body temperature in early postmortem period could be a reasonable explanation for the variation of meat quality parameters.

• Asian-Australasian Journal of Animal Sciences
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• 제16권8호
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• pp.1218-1223
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• 2003

The effects of type (high and low voltages) and time (3, 40 and 60 min postmortem) of stimulation on drip loss and meat color at 24 h post-mortem were determined on M. longissimus dorsi of 38 crossbred steers and heifers. In addition, the effect of pH early postmortem (70 min postmortem) on the rate and extend of meat tenderization was examined. Either high or low voltage stimulation at 3 min showed a tendency for faster pH decline (p=0.052) and higher drip loss (p=0.08), and improved the color dimensions of L*, a* and b* (p<0.01), compared to stimulation at 40 min. This was equivalent to approximately one unit of an AUSMEAT color chip. On the other hand, although there were significant differences in pH decline between high voltage stimulation at 40 and 60 min, and between low voltage stimulation at 40 min and control sides, drip loss and meat color did not differ significantly (p>0.05). The results suggested that early application of stimulation, regardless of type of stimulation, improved overall meat color at 24 h postmortem through its effect on faster glycolysing rate. However, if the pH decline was moderate, the benefit of electrical stimulation on meat color was not apparent. An intermediate pH decline resulted in the lowest shear force. Due to differential ageing rates the optimum pH at 70 min postmortem increased with ageing time from 5.96, 6.07, 6.12 and 6.14 for 1, 3, 7 and 14 days postmortem, respectively. This implied that a small difference in the rate of pH decline was important, especially carcasses stimulated for very early postmortem, and the optimum rate of pH decline varied with intended ageing period. The study suggests that the beneficial or adverse effects of electrical stimulation on drip loss, meat color and tenderness is determined by the rate of pH decline, rather than by stimulation treatment and time of application per se.

• Asian-Australasian Journal of Animal Sciences
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• 제20권4호
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• pp.598-604
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• 2007

The current study was conducted to evaluate carcass characteristics, objectives and sensory meat qualities of Hanwoo longissimus muscle as affected by ultimate pH. Twenty-four steers and bulls ($556{\pm}53$ kg and $0.63{\pm}0.32$cm for live weight and backfat thickness, respectively) were used. As there was a linear relationship (r = 0.77) between lean meat color and ultimate pH, cattles were thus segregated into normal $pH{\leq}5.8$, Normal, n = 13) and DFD (pH>5.8, n = 11) groups. Normal pH group had significantly (p<0.05) higher carcass weight, marbling score and backfat thickness than those for high pH group, while fat color and lean meat color were inverse. In principle component analysis for co-ordinates of DFD and normal meats, fat color, lean meat color, texture, time to pH 6.2 and pH at 24 h postmortem were associated with the positive range of the first factor (67.5%) while backfat thickness marbling score and temperature at 24 h were placed in negative values. The rate constant of decline in pH (pH k) did not differ between the two groups, implying that initial pH (i.e., pH at slaughtering) differed between two groups. Contour mapping of pH k between pH at 1 and 24 h postmortem indicated that high pH k was related to lower pHs at 1 and 24 h postmortem. This suggested that the high pH cattles (i.e., DFD cattle) resulted from their own potential. Although the time to reach pH 6.2 was significantly (p<0.05) shorter for normal meat (i.e., 3.2 h) than that for DFD one (i.e., 19.8 h), there were no significantly differences in both WB-shear force and sensory attributes. Given that the experimental animals were sampled from a similar group, which implies a similar myoglobin pigment content, the current data suggested that pre- and post-slaughter animal handling likely had a significant effect on ultimate pH and consequently meat color of Hanwoo longissimus muscle, and also small animals with lower marbling score and backfat thickness had a higher risk for DFD meat.

• Asian-Australasian Journal of Animal Sciences
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• 제15권12호
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• pp.1677-1679
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• 2002

This experiment was carried out to evaluate the tenderness of meat and it''s correlation with other carcass traits of Hanwoo steers. The significantly (p<0.01) higher mastication and shearing were observed in boiled meat than in the raw meat but the coefficient of variations were greater in raw meat than in boiled meat. The correlation between raw and boiled meat for shearing and penetration were positive and significant (p<0.01). Negative and significant correlations were observed between mastication and eye muscle area (p<0.05) and also between shearing and cooking loss (p<0.01) in raw meat whereas, penetration in raw meat was positively and significantly (p<0.05) correlated with age of the steers. Shearing in boiled meat negatively and significantly correlated with age (p<0.05), carcass weight (p<0.01), back fat thickness (p<0.01) as well as muscle score (p<0.01). The pH was not significantly correlated with tenderness in both raw and boiled meat. There were possibilities that the tenderness of boiled meat could be predicted from the raw meat.

• 한국축산식품학회지
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• 제36권1호
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• pp.84-89
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• 2016

The objective of this study was to compare carcass composition and meat quality traits in the longissimus dorsi and biceps femoris muscles in the Hyla, Champagne and Tianfu Black rabbit breeds. Tianfu Black rabbits had the heaviest head, skin, thoracic viscera and commercial carcass percentage (p<0.05). In addition, Tianfu Black had the highest pH_{0 h} value, followed by the Champagne and Hyla breeds (p<0.01) in the longissimus dorsi and biceps femoris muscles. Tianfu Black had a higher a* (0 h and 24 h) than the other two breeds in both longissimus dorsi and biceps femoris muscles (p<0.05). The Hyla, Champagne, and Tianfu Black breeds showed a similar pattern of differences for meat quality traits (pH, L*, a* and b*) measured in fresh meat (0 h) and meat stored for 24 h. Hyla had the highest IMF values of the three breeds (p<0.01). The lower intramuscular fat of Tianfu Black and Champagne rabbits gives them an advantage over Hyla rabbits among most consumers seeking lean rabbit meat.

• Asian-Australasian Journal of Animal Sciences
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• 제21권11호
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• pp.1616-1623
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• 2008

This study was conducted to determine the effect of hot environment and dietary crude protein level (CP) on performance, carcass characteristics, meat visual quality, muscle chemical composition and malondialdehyde (MDA) concentration of tissues in broilers. Two hundred and sixteen 21-d old Arbor Acre broilers were used in a $4\times3$ factorial arrangement and randomly reared in 4 environmental chambers and fed on 3 diets with different CP levels for 3 weeks. The results showed: (1) when air temperature (AT) rose to $33^{\circ}C$, average daily feed intake, average daily gain, carcass weight, right breast meat weight, left thigh and drumstick meat weight decreased (p<0.05) and feed conversion rate decreased (p<0.05), but the ratio of carcass to live weight and of left thigh and drumstick meat weight to carcass weight increased (p<0.05). (2) There were significant differences in pH and shear force in breast meat, and shear force, L* and a* in thigh meat (p<0.01 or 0.05) among hot environments. Dietary CP level tended to affect breast meat pH and pH and L* of thigh meat (p<0.06 or 0.09). Compared to the normal temperature ($22^{\circ}C$), low temperature ($15^{\circ}C$) and hot humid (AT $33^{\circ}C$, relative humidity (RH) 80%) treatments significantly (p<0.05) decreased the tenderness of thigh meat. L* and a* value in thigh meat under high temperature treatments, regardless of RH, were higher (p<0.05) than those under normal temperature. (3) Protein content in breast and thigh meat of broilers fed under high temperature ($33^{\circ}C$) was lower (p<0.05) than that under $22^{\circ}C$, but fat content had an adverse change. High temperature ($33^{\circ}C$) increased the moisture of breast meat significantly (p<0.05). Protein content in breast meat increased significantly (p<0.05), in which fat content had an adverse change (p<0.05), when the dietary protein rose. (4) MDA concentration in liver and breast meat under hot humid (AT $33^{\circ}C$, RH 80%) treatment increased markedly (p<0.05). (5) High humidity could sharpen the bad effect of high temperature on performance, carcass yield and choice cuts, crude protein and moisture content in breast meat. It was concluded that a hot environment could affect the performance and meat quality of broiler chicks more significantly than CP level and that high humidity would aggravate the bad influence of high temperature on the broiler.

• 한국가금학회지
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• 제33권1호
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• pp.7-14
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• 2006

함기 포장과 진공 포장이 냉장 저장 중 오리고기의 육색, 지방 산화 및 지방산 조성에 미치는 영향을 조사하였다. pH는 가슴육이 다리육에 비해 낮았으며, 냉장 저장 중 가슴육이 다리육에 비해 육색의 변화가 크게 나타났다. 다리육의 조지방 함량이 가슴육에 비해 약2배 정도 높았으며, 저장 3일 째부터 전단가가 낮아졌다. 함기 포장은 진공 포장에 비해 냉장저장 중 다리육의 지방 산화를 촉진하는 것으로 나타났으며, 지방 산화는 palmitic acid 함량의 감소와 linoleic acid 함량의 증가와 관련이 있는 것으로 나타났다 결과적으로 오리고기의 장기적인 냉장 유통을 위해서는 함기 포장보다 진공 포장을 하는 것이 바람직할 것으로 사료된다.

• Journal of Animal Science and Technology
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• 제53권4호
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• pp.289-296
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• 2011

본 연구는 2004년~2008년에 미국에서 도입한 버크셔종의 육질 형질에 대한 유전적 특성을 파악하고, 향후 선발에 이용한 유전적 그룹(genetic group)을 분리하여 선발 및 교배계획을 체계적으로 세워 효과를 극대화시키는 전략을 세우고자 수행하였다. 그 결과 사후 대사율의 척도인 근육의 사후 45분 pH, 24시간 pH에 대한 유전력은 각각 0.60과 0.61로 높게 조사되었다. 육색의 척도인 명도, 적색도 및 황색도의 유전력은 0.56, 0.58 및 0.62로 조사되었다. 근내지방도, 유리육즙량과 가열감량에 대한 유전력은 각각 0.57, 0.51 및 0.66으로 조사되었다. 본 연구 결과로 미루어 볼 때 육질형질의 개량에 있어 육종가를 기초로 하여 선발에 활용할 경우 유전적 개량량은 크게 나타날 것으로 사료된다. 또한 사후 대사율의 척도인 pH와 육질형질과의 상관도는 높은 연관성이 존재하므로, 종돈장에서 육질형질을 개량하고자 한다면 육종가를 기반으로 한 선발지수(selection index)를 활용하면 매우 효과적일 것으로 필자는 사료된다. 그러나 본 연구에 활용된 자료는 유전모수를 추정하는데 다소 부족한 것은 사실이지만 국내 최초로 돼지의 육질형질에 대한 유전모수를 추정하는데 있어 매우 의미가 있다고 할 수 있다.

• Journal of Animal Science and Technology
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• 제58권7호
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• pp.27.1-27.8
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• 2016

Background: Studies on prevalence of pale, soft, exudative (PSE) condition in Sri Lankan poultry industry is minimal. Hence, the objective of present study was to determine the incidence of PSE chicken meat in a commercial meat processing plant and to find out its consequences on meat quality traits of roasted chicken breast. Method: A total of 60 breast fillets were randomly selected, evaluated based on color L* value, and placed into 1 of 2 categories; PSE (L* > 58) or normal meat ($L*{\leq}58$). A total of 20 breast fillets (10 PSE and 10 normal) were then analyzed for color, pH, and water holding capacity (WHC). After processing those into roasted chicken breast, cooking loss, color, pH, WHC, and texture values were evaluated. A sensory evaluation was conducted using 30 untrained panelists. Results: The incidence of PSE meat was 70 % in the present experiment. PSE fillets were significantly lighter and had lower pH values compared with normal fillets. Correlation between the lightness and pH was negative (P < 0.05). Although there was no significant difference in color, texture, and WHC values between the 2 groups after processing into roasted chicken breast (P > 0.05), an approximately 3 % higher cooking loss was observed in PSE group compared to its counterpart (P < 0.05). Moreover, cooking loss and lightness values showed a significant positive correlation. Nevertheless, there were no significant differences in sensory parameters between the 2 products (P > 0.05). Conclusions: These results indicated that an economical loss can be expected due to the significantly higher cooking loss observed in roasted breast processed from PSE meat.

• Asian-Australasian Journal of Animal Sciences
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• 제28권10호
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• pp.1388-1393
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• 2015

Genetic parameters of Berkshire pigs for reproduction, carcass and meat quality traits were estimated using the records from a breeding farm in Korea. For reproduction traits, 2,457 records of the total number of piglets born (TNB) and the number of piglets born alive (NBA) from 781 sows and 53 sires were used. For two carcass traits which are carcass weight (CW) and backfat thickness (BF) and for 10 meat quality traits which are pH value after 45 minutes (pH45m), pH value after 24 hours (pH24h), lightness in meat color (LMC), redness in meat color (RMC), yellowness in meat color (YMC), moisture holding capacity (MHC), drip loss (DL), cooking loss (CL), fat content (FC), and shear force value (SH), 1,942 pig records were used to estimate genetic parameters. The genetic parameters for each trait were estimated using VCE program with animal model. Heritability estimates for reproduction traits TNB and NBA were 0.07 and 0.06, respectively, for carcass traits CW and BF were 0.37 and 0.57, respectively and for meat traits pH45m, pH24h, LMC, RMC, YMC, MHC, DL, CL, FC, and SH were 0.48, 0.15, 0.19, 0.36, 0.28, 0.21, 0.33, 0.45, 0.43, and 0.39, respectively. The estimate for genetic correlation coefficient between CW and BF was 0.27. The Genetic correlation between pH24h and meat color traits were in the range of -0.51 to -0.33 and between pH24h and DL and SH were -0.41 and -0.32, respectively. The estimates for genetic correlation coefficients between reproductive and meat quality traits were very low or zero. However, the estimates for genetic correlation coefficients between reproductive traits and drip and cooking loss were in the range of 0.12 to 0.17 and -0.14 to -0.12, respectively. As the estimated heritability of meat quality traits showed medium to high heritability, these traits may be applicable for the genetic improvement by continuous measurement. However, since some of the meat quality traits showed negative genetic correlations with carcass traits, an appropriate breeding scheme is required that carefully considers the complexity of genetic parameters and applicability of data.