The effect of transportation on the expression of heat shock proteins and meat quality of M. longissimus dorsi in pigs.
ABSTRACT This study investigates the effect of different transport times on meat quality and the correlation between meat quality and Hsp expression in M. longissimus dorsi (LD) of pigs. After transportation for 1h, 2h or 4h, respectively, blood plasma creatine kinase (CK) and lactate dehydrogenase (LDH) increased. The LD meat from 1h and 2h transported pigs had lower initial and ultimate pH values (pHi and pHu, respectively), higher drip loss and L(∗) values compared to controls, indicating a higher likelihood of pale, soft and exudative (PSE) meat. Meat quality was lower after 2h compared to 1h or 4h of transport. All four Hsps tested (alpha-B-crystalline, Hsp27, Hsp70 and Hsp90) by ELISA in the LD tissue of pigs tended to decrease after transportation. One possible mechanism resulting in poor meat quality in the LD after transport seems to be a decline in Hsp expression.
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ABSTRACT: 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 (pHu) 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 (705.380.57 U/L) and pHu (6.30.05) values while the Bonsmara had the highest L* (24.80.78) a* (17.50.53) and b* (12.80.53) 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. (Key Words: Age at Slaughter, Beef Quality, Bruising, Creatine Kinase, Meat pH, Season)
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ABSTRACT: ABSTRACT: The objective of the current study was to determine the effect of pre-slaughter stress, season and breed on the activity of plasma creatine kinase (CK) and the quality of mutton. One hundred and seventy-three (173) castrated sheep from Dormer (DM), South African Mutton Merino (SAMM), Dorper (DP) and Blackhead Persian (BP) sheep breeds were used in the study. The animals were grouped according to age-groups as follows: Group 1 (6 to 8 months), Group 2 (9 to 12 months) and Group 3 (13 to 16 months). Blood samples were collected during exsanguinations using disposable vacutainer tubes for CK analysis. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL) were collected from 84 castrated sheep, of different breeds (28 per breed) 24 h after slaughter. The following physico-chemical characteristics of mutton were determined; meat pH (pH24), color (L*, a* and b*), thawing and cooking losses and Warner Braztler Shear Force (WBSF). The activity of plasma CK was significantly higher (p<0.001) in summer (1,026.3105.06) and lower in winter (723.377.75). There were higher values for L* (33.70.94), b* (11.50.48) and WBSF (29.51.46) in summer season than in winter season; L* (29.40.64), b* (10.20.33) and WBSF (21.20.99). The activity of plasma CK was influenced by the type of breed with Dormer having the highest (p>0.001) levels (1,358.6191.08) of CK. South African Mutton Merino had higher values for pH24 (5.90.06), L* (34.20.97), b* (12.20.50) and WBSF (26.81.51) and Blackhead Persian had higher values (35.52.17) for cooking loss (CL%) than the other breeds. Computed Principal Component Analyses (PCA) on the activity of plasma CK and physico-chemical characteristics of mutton revealed no correlations between these variables. However, positive correlations were observed between pH24, L*, a*, b*, CL% and WBSF. Relationships between pre-slaughter stress, CK activity and physico-chemical characteristics of mutton were also observed. It was therefore concluded that although mutton quality and creatine kinase were not related, pre-slaughter stress, season and breed affected the activity of creatine kinase and mutton quality. (Key Words: Abattoir, Enzymes, Color, Meat pH, Temperature, Tenderness)Asian Australasian Journal of Animal Sciences 12/2013; 26(12):1762-1772. · 0.56 Impact Factor
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ABSTRACT: The antioxidant enzyme, copper zinc superoxide dismutase (CuZnSOD) plays an important role in protecting tissues from damage by reactive oxygen species (ROS) reactions. The objective of this investigation was to determine the CuZnSOD mRNA level as an indicator of CuZnSOD activity and the effect it has on meat quality in three important pig breeds in China, the Laiwu Black (LW), Lulai Black (LL) and Large Yorkshire (LY). Thirty six castrated boars (114 kg; LW, n = 12; LL, n = 12 and LY, n = 12) were used in this study. Samples were taken from the longissimus dorsi muscle, backfat and liver. Results showed that there was a significant breed × tissue interaction; and the maximum mRNA level of the CuZnSOD gene was recorded in the LW and the minimum in the LY. The proportion of gene expression was positively correlated with the anti-oxidative capacity in muscle. The expression of the CuZnSOD gene was positively correlated with meat colour and tenderness; and negatively correlated with marbling score, drip loss, cooking loss and intramuscular fat. The higher the level of CuZnSOD mRNA expression, the better was the quality of the pork. This implies that the difference in CuZnSOD mRNA expression in breeds was involved in the mechanisms of meat quality that related to superoxide dismutase (SOD) activity and anti-oxidant capacity of the muscle.South African Journal Of Animal Science 12/2009; 40(3):265-272. · 0.35 Impact Factor