Correlation between circulating cortisol and indicators of stress and oxidant stress during the preslaughter operations in camels

Abstract

In livestock, pre-slaughter stress begins at the farm or market, continues during transport and upon arrival at the slaughterhouse, ending at slaughter. In this investigation, a survey was conducted in the slaughterhouse of Casablanca in Morocco to record the duration of the preslaughter operations and the frequency of urination in camels. Two groups of camels were constituted, the least stressed animals (Group I, n= 12) and the most stressed animals (Group II, n= 12). Group I animals had a waiting time before loading ≤ 24 h, a loading time ≤ 15 min, an unloading time ≤ 5 min, a water and food deprivation time before slaughter ≤ 24 h, a duration of accompaniment to the slaughter room ≤ 11 min and a frequency of urination during this accompaniment < 3 times. Those in group II had higher duration and frequency values for the same parameters. In addition, serum stress [cortisol (COR)], oxidant stress biomarkers [malondialdehyde (MDA)] and activities of catalase (CAT) and superoxide dismutase (SOD) were analyzed in both groups, and correlations between these biomarkers and the durations of various preslaughter operations and the frequency of urination were established. The most stressed camels (G II) showed high serum concentrations of COR and MDA, and low CAT and SOD activities by comparison to the less stressed camels (G I) (P<0.05). Significant correlations were recorded between COR, MDA, CAT and SOD, and the durations of various preslaughter operations, and between COR and the frequency of urination.