Effects of transport stress and rest before slaughter on blood parameters and meat quality of ducks

Ducks have been transported to be slaughtered at centralized locations since the 2013 avian influenza A (H7N9) epidemics in China. It is unavoidable that a certain amount of stress will occur during the transportation. We investigated the effects of transport stress and rest before slaughter on blood parameters and meat quality in ducks. Pekin ducks (42 d old) were randomly divided into six groups. Each group had five replicates, with four ducks in each replicate. The experimental design included the variables transport time and rest time before slaughter. Transport distance categories were short-distance (1 h transport; n = 20), medium-distance (2 h transport; n = 20) and long-distance (3 h transport; n = 20) transport. Rest time was categorized as short (0.5 h; n = 20) or long (2 h; n = 20) periods of rest. Blood samples and meat samples were collected after transport or after the post-transport rest period. Blood indicators (triiodothyronine, thyroxine, insulin, glutamicpyruvic transaminase, aspartate transaminase, creatine kinase, and glutathione peroxidase) were measured using enzyme-linked immunosorbent assay (ELISA) kits. Meat quality characteristics (meat component, pH, malondialdehyde, and protein carbonyl) were also measured. Triiodothyronine, thyroxine, aminotransferase, glutamic-oxaloacetic transaminase, creatine kinase, glutathione peroxidase, pH, malondialdehyde, and protein carbonyl values changed significantly in ducks exposed to the medium-distance transport treatment. Stress indicators improved and meat quality returned to normal by the end of a 2-h pre-slaughter rest. These results indicate that a 2-h transport causes serious stress in ducks. A 2-h rest before slaughter mitigates these adverse effects.