The objectives of the present experiment were 1) to study the effects of transport conditions and lairage duration on stress level, muscle glycolytic potential, and pork quality; and 2) to investigate whether the negative effects of high stress immediately preslaughter are affected by preceding handling factors (transport and lairage). In a 2 x 2 x 2 factorial design, halothane-free pigs (n = 384) were assigned to either short (50 min) and smooth or long (3 h) and rough transport; long (3 h) or short ( 0.30), tended to increase (P = 0.06) muscle glycolytic potential. Long transport tended to increase (P = 0.08) electrical conductivity, and decreased a* (P <0.01) and b* (P <0.02) values. Decreasing lairage from 3 h to 0.10) affect other pork quality traits. High stress decreased (P <0.001) muscle glycolytic potential, and increased (P <0.001) plasma lactate, cortisol, muscle temperature, rate of pH decline, and ultimate pH. Except for decreased (P <0.001) b* values, pork color was not (P > 0.40) affected by high stress, but water-holding properties (measured by electrical conductivity, filter paper moisture, and drip loss) were impaired (P <0.001) by high stress. Fiber optic-measured light scattering and Warner-Bratzler shear force were not (P > 0.12) affected by any treatment. Comparisons with the "optimal" handling (short transport, long lairage, and minimal stress) revealed that, with regard to water-holding properties, the negative effects of high stress were aggravated by suboptimal transport and lairage conditions. High stress alone increased electrical conductivity by 56%, whereas high stress in combination with short lairage led to an 88% increase. However, high preslaughter stress contributed most and was the major factor responsible for reductions in pork quality.
|Journal||Journal of Animal Science|
|Publication status||Published - 2005|
- meat quality
- halothane genotype
- preslaughter stress
- feed withdrawal
- carcass yield