Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523-1171, United States.
Meat Sci, 2010 Jul 29.
Second author's additional comment: Another study published by the same research group (Edwards et al 2010, Meat Sci 86:384-390) showed that the use of electric prods, pigs jamming, rearing up or backing up in the single file race to the stunner was associated with higher lactate levels. Therefore handling stresses that occur approximately five minutes before stunning will increase lactate levels. Increased lactate levels shortly before slaugher are associated with lower 60 min pH and higher drip loss whch are both indicators of lower pork quality (Edwards et al, 2010, Meat Sci 85:435-440). The above abstract shows that a stress that raises lactate several hours before slaughter will raise muscle pH. A basic pricinciple is a short term stress within 5 to 10 minutes prior to slaughter lowers pH and a long term stress which occurs many hours before slaughter usually raises pH.
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