Effect Of Pre-Slaughter Conditions On Beef Quality

The quality of beef is an important indicator which can measure the commercial value of beef, however the inferior beef happened and had high incidence post-mortem become a difficult problem which have tended to restrict the rapid development of Chinese beef manufacturers. The pre-slaughter conditions have effect on the quality of beef, such as breed, gender, age, season, transportation time and density, lairage state and time, slaughter method, and so on. The incidence of inferior beef had been decreased effectively and the quality of beef had been raised by scientific and normative pre-slaughter managements.This study researched on some aspects of pre-slaughter conditions, the effect of pre-slaughter conditions on beef quality had been studied, and the mechanism of inferior beef had been probed by the relationship between muscle glycogen and pH value post-mortem.The results of this study are as follows:1. Pre-slaughter managements of a beef manufacturer had been studied, and the ultimate pH value had been measured and analyzed. Results revealed that the incidence of DFD beef was higher in summer than in winter. Lairage density, temperature and humidity, and short distance transportation had effect on the incidence of DFD beef slightly. The incidence of DFD beef was lower when the bull slaughtered in the morning.2. When the pre-slaughter conditions had been controlled, the incidence of DFD beef had been studied in different season. Results revealed that lairage time was the important factor which could influence the incidence of DFD beef, the incidence of DFD beef was the lowest when lairage time was 24 h, and higher when 16 h. Unmixed group of cattle before slaughter, quiet environment, appropriate temperature and humidity lairage conditions could decrease the incidence of DFD beef availably. The incidence of DFD meat was lower when the bull had experienced 24 h lairage and stunned slaughter method in winter morning. The DFD beef happened post-mortem could be to avoid when the bull experienced lairage before transportation.3. The quality of beef sample had been studied, and then the results revealed that in summer, the incidence of PSE beef was higher when the bull had experienced Islam slaughter method. The pre-slaughter managements were better when the bull experienced lairage 8 h after transportation, lairage 24 h after transportation, lairage 24 h before transportation. b* which is the variable of beef color was more important than L* to estimate inferior beef.The interrelationship between pre-slaughter conditions and quality of beef was remarkable, and the systems of regression equations had been built. To estimate the DFD beef, the criterion is pH24 value≥6.10, L*<37.40±3.78, b*<10.25±1.94, Drip loss<7.36%±2.81%. When pH24 value≥6.10, the beef quality was changed greatly.4. The pH value and muscle glycogen post-mortem had been measured. Results revealed that muscle glycogen was the better indicator which could response the pre-slaughter stress, the muscle glycogen was decreased markedly when the bull experienced the stress. The incidence of DFD meat had been to avoid by higher muscle glycogen before slaughter. The beef quality could not be predicted when the lairage time is 16 h.