اثر تراكم و دو روش كشتار بر شاخص هاي فيزيولوژيك خون و برخي خواص فيزيكوشيميايي

Treatment of sub-optimum performance in a dairy herd: the necessity of intensive investigations and some limitations

In this study effects of two slaughtering procedures that were asphyxia and percussion on physiological blood factors and physicochemical muscle attributes, determined in order to evaluate imposed stress and meat quality in common carp. Results showed crowding and two different slaughtering methods significantly affected on plasma cortisol, glucose, lactate, calcium and magnesium (P < 0.05). Asphyxia decreased chloride but did not affect total protein plasma levels (P > 0.05). pH in percussion groups was higher than asphyxia groups immediately after death. Percussion fish had the highest and asphyxia groups had the lowest level of water holding capacity than other groups. Crowding and asphyxia killing method significantly increased drip loss as compared to uncrowding and percussion killing methods (P < 0.05). Fishs in asphyxia group exhibited a faster onset of rigor mortis than other groups. Although two slaughtering procedures did not affect on fillet color (P > 0.05), however colorimetric results showed significant differences in the skin color parameters among different groups during post mortem time (P < 0.05). In conclusion, the results revealed that over crowding and asphyxia slaughtering procedures impose maximum stress to fish and reduce meat quality and on the hand, uncrowding and percussion had no imposed stress fish and their meat quality was better than other groups.