Show simple item record

dc.contributor.advisorShand, Phyllisen_US
dc.creatorDadgar, Samiraen_US
dc.date.accessioned2010-08-10T11:53:37Zen_US
dc.date.accessioned2013-01-04T04:52:23Z
dc.date.available2011-08-13T08:00:00Zen_US
dc.date.available2013-01-04T04:52:23Z
dc.date.created2010-08en_US
dc.date.issued2010-08en_US
dc.date.submittedAugust 2010en_US
dc.identifier.urihttp://hdl.handle.net/10388/etd-08102010-115337en_US
dc.description.abstractSeveral 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). 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. 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. 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. 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.en_US
dc.language.isoen_USen_US
dc.subjectMeat qualityen_US
dc.subjectCold stressen_US
dc.subjectPost-mortem metabolismen_US
dc.subjectBroiler chickenen_US
dc.subjectTransportationen_US
dc.titleEffect of cold stress during transportation on post-mortem metabolism and chicken meat qualityen_US
thesis.degree.departmentApplied Microbiology and Food Scienceen_US
thesis.degree.disciplineApplied Microbiology and Food Scienceen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophy (Ph.D.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US
dc.contributor.committeeMemberTanaka, Taken_US
dc.contributor.committeeMemberOwens-Hanning, Caseyen_US
dc.contributor.committeeMemberPietrasik, Zeben_US
dc.contributor.committeeMemberPato, Maryen_US
dc.contributor.committeeMemberClassen, Hanken_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record