Effectiveness of poll stunning water buffalo with captive bolt guns

The welfare of water buffaloes during the slaughter process: A review

“…After application of the stun procedure, the animals must be bled as soon as possible (Terlouw et al, 2016a). In cattle and water buffaloes, exsanguination is usually performed by severing the carotid arteries and jugular veins on the ventral neck (ventral neck incision) or cutting the brachiocephalic trunk (chest stick or thoracic stab) (Gregory et al, 2009c;Robins et al, 2014). The devastating effect of the haemorrhage during bleeding is mostly related to the lack of oxygenation of the organs, this can cause irreversible cessations of brain, structures responsible for vital functions like breathing, thermal and cardiovascular regulation and this can cause final cardiac arrest.…”

“…Placement of the captive bolt shot has a significant effect on stunning performance. Gregory et al (2009c) evaluated the efficacy of different captive bolt stunning sites (frontal, crown and poll) in water buffalo with different gun/cartridge combinations. They reported that bulls over 30 thirty months old (skull thickness at the frontal position = 8 cm) shot in the frontal position did not collapse after the first shot.…”

“…In poll-shot water buffaloes 79% had damage to the cerebellum, and 71% to the medulla and/or pons. However, 3 of the animals that were shot in the poll position were considered to have been shot improperly because the bolt went into the spinal cord (n=2) or did not penetrate the brain (n=1) (Gregory et al, 2009c). Similar work by Schwenk et al (2016) reported that shooting in the poll position (depression below the intercornual protuberance but above the attachment points of the Ligmenta nuchae), dramatically reduces the bone-to-thalamus distance to a median of 87 mm (range: 81-98 mm), compared to 127 mm (range 93-106 mm) for the frontal position.…”

“…Shots in this position should be directed towards the base of the tongue in buffaloes under three months of age, but towards the nose in older animals. The shot also needs to be directed rostrally to ensure that the brain, and not only the spinal cord is penetrated (Gregory et al, 2009c). However, some authors consider the occipital position of the stunner unsuitable for practical reasons, as some buffaloes show interest in the device and may tend to move their heads (Meichtry, 2015).…”

Assessing unconsciousness in livestock at slaughter

“…A study by showed that a protruding tongue was not associated with depth of concussion after captive bolt stunning, but was proposed as indicator following exsanguination, when 40% of the cattle had a protruding tongue while hanging on the bleeding rail. Similarly, relaxation of the jaw may be taken into account, but can be observed in unconscious animals (Gregory et al, 2009a). Both jaw relaxation and tongue protruding are not used as single indicators to assess unconsciousness, but can support other indicators of unconsciousness (Grandin, 2002;von Holleben et al, 2010).…”