The effect of pre-slaughter electrical stunning on bleeding efficiency, meat quality, histology, and microbial count of several goat muscles

Abstract

This study was designed to compare the effect of non-electrical stunning and electrical stunning on bleeding efficiency, meat quality characteristics, bacterial count, and histology of longissimus thoraces, semitendinosus, biceps femoris, infraspinatus, semimembranosus, and triceps brachii muscles of goats. Forty goats were randomly divided into two groups: electrical stunning and non-electrical stunning with 20 animals each. Low frequency head-only electrical stunning of 1 Amp for 3 s at a frequency of 50 Hz was used. The slaughter was performed by severing the carotid artery, jugular vein, trachea, and oesophagus. Six muscles were kept in a chiller at 3–4 ºC for 24 h before quality measurements. Samples from the infraspinatus, longissimus thoraces, and semitendinosus muscles were preserved to evaluate histological features. Muscle samples from the non-electrical stunning group had substantially higher blood loss and lower bacterial counts after 72 h across the six muscles compared to the electrical stunning group. No significant differences in meat quality parameters were evident between the two groups. The stained sections of the electrically-stunned muscle samples detected alteration phenomena due to the presence of muscle fibres with split myofibres and myofibres with central rather than peripheral nuclei. Electrical stunning prior to slaughter increased bacterial contamination, decreased blood loss, and altered the position of muscle nuclei.