Can Dietary Pomegranate Peels Reduce Stress Responses Associated with Group Mixing of Holstein Beef Calves?

The study investigated whether dietary CPE (concentrated pomegranate peel extract) may mitigate the negative effects associated with group mixing prior to marke ting and enhance beef meat quality. Twenty-two bull calves were reared in triplets and divided to control (n = 9) and CPE-treated (n = 13) groups. CPE was supplemented during eight months of rearing, and calves were mixed 34 d prior to marketing to control and treatment groups. Calves were monitored for weight gain, rumination, activity, metabolic and oxidative stress responses. Finally, meat quality traits were examined. The results find that pre-mixing activity (P < 0.0001), non-esterifies fatty acids (P = 0.02) and plasma testosterone (P = 0.005) levels were higher in the treatment group. Following mixing, activity (P < 0.0001) and plasma anti-oxidative capacity (P = 0.05) increased in the treatment compared to the control group. In spite of the above, dietary supplementation of CPE didn’t reveal improvement of meat quality parameters by means of meat pH and shelf life. It indicated that improved serum anti-oxidant capacity in the CPE calves was not sufficient to prevent the mixing effects on meat quality. A combined CPE concentration and mixing management should be examined in order to reduce mixing related effects on meat quality.