Several studies were designed to investigate effect of cold winter transportation on broiler meat quality and physiological parameters. The first study assessed the effect of microclimate environment during winter transportation (-27 to +11ºC) from farm to the processing plant (3-4 h) on core body temperature (CBT) and breast meat quality parameters of 522 broiler chickens using an actively ventilated transport vehicle. Temperatures below freezing during transportation resulted in significantly (P < 0.05) higher ultimate pH (pHu) and darker color breast meat, which led to 8% incidence of dark, firm and dry (DFD) breast meat (pH > 6.1; L*< 46).<p>
The effects of extreme cold conditions (-18 to -4ºC) along with age (5 and 6 wk), gender and lairage (0 and 2 h) on physiology parameters, breast muscle metabolites and meat quality of 360 birds using a simulated transport system were investigated. Five and 6 wk birds exposed to temperatures below -8 and -14ºC, respectively, showed significantly (P < 0.05) lower CBT and blood glucose and higher live shrink with breast meat that was darker in color, higher in pHu, water holding and water binding capacity compared to breast meat of birds exposed to warmer temperatures. A high incidence of DFD breast meat (> 50%) was observed for 5 and 6 wk birds exposed to temperatures below -8 and -14ºC respectively. Lairage following acute cold exposure caused an increase of up to 20% in DFD breast meat following exposure of the birds to temperatures below -8ºC.<p>
Characteristics of cold-induced DFD breast meat were investigated in broiler chickens. DFD breast meat was significantly darker, redder, and less yellow in color and had higher pH, water binding capacity, processing cook yield and lower thaw and cook loss compared to normal meat. However, no significant difference in initial energy reserves was observed between DFD and normal breast meat.<p>
Effect of extreme cold-stress (-15 to -9ºC) was further assessed on thigh meat quality and incidence of DFD from 160 male broilers. A greater impact of cold stress was observed on muscle metabolites and pH of thigh compared to breast meat, with 85% DFD incidence in thigh compared to 42% in breast meat of cold-stressed birds.<p>
Biochemical basis of cold-induced DFD breast and thigh meat was investigated by measuring muscle metabolites at different times post-mortem. Lack of energy reserves at slaughter clearly explained the incidence of DFD thigh meat, but other factors might contribute to DFD breast meat aside from glycogen reserve at slaughter. However, the factors leading to DFD breast meat still remain unresolved and association of post-mortem enzyme activity and development of DFD breast meat merits further investigation.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-08102010-115337 |
| Date | 13 August 2010 |
| Creators | Dadgar, Samira |
| Contributors | Tanaka, Tak, Owens-Hanning, Casey, Shand, Phyllis, Pietrasik, Zeb, Pato, Mary, Classen, Hank |
| Publisher | University of Saskatchewan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-08102010-115337/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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