Assessment of stun quality after gunshot used on cattle: a pilot study on effects of diverse ammunition on physical signs displayed after the shot, brain tissue damage and brain haemorrhages

Abstract

Moving the slaughter process from the abattoir to the animals’ familiar environment has the potential to reduce pre-mortal stressors to a minimum and contribute considerably to improved animal welfare at slaughter. On-farm stunning and killing of free-range cattle via gunshot became legal in Germany in November 2011, including for commercial sale of the meat. As an effective stun is essential for maintaining animal welfare until the animal dies, the goal of this study was to assess the feasibility of delivering an instantaneous and deep stun by an accurate frontal gunshot at cattle. Thirty free-range cattle (Galloway, German Angus) were shot with five different combinations of rifles and bullets. A stun-quality protocol was developed to assess musculoskeletal, optical and respiratory signs displayed after the shot. Key signs, such as failure to collapse, corneal reflex, spontaneous blinking, eyeball rotation or eyeball movement, distinct vocalisation and rhythmic breathing were not evident in 29 of the 30 cattle. Dissections of the heads were used to detect penetration depth of the projectile as well as evaluate brain tissue damage and brain haemorrhage caused by the shot. Tissue damage was marginal and not related to the ascertained level of stun quality. Brain haemorrhages assumed to be sufficient for causing a deep stun were detected in 25 out of 30 cattle. Accurate shot placement turned out to be more important than the application of a certain calibre. However, it was considered crucial for safety reasons that the projectile should remain within the cranial cavity. As long as there are high levels of accuracy, gunshot was considered to be an effective stunning method with the potential of maintaining high standards of animal welfare until death occurs.

Use of on-farm emergency slaughter for dairy cows in British Columbia

“…The Humane Slaughter Association recommends that cattle stunned by a penetrative tool, such as a firearm (as is the case with OFES), are bled within 60 s to ensure death (HSA, 2016). However, if the firearm caliber is sufficient for the size of the cow, a correctly placed shot can kill the animal by destroying the brain stem (Appelt and Sperry, 2007;Shearer and Ramirez, 2013;Schiffer et al, 2017). Hence, the slightly longer delay before bleeding when done under farm conditions should not result in animal suffering if the firearm is correctly used.…”

Animal Welfare and Food Safety When Slaughtering Cattle Using the Gunshot Method

“…In line with previous research [ 26 , 35 ], the extent and degree of lesions and haemorrhages in the brain were assessed from the photographs. Brain tissue damage was characterized as ‘severe’ when there was a complete destruction of the brainstem (composed of the midbrain, the pons and the medulla oblongata), and ‘marginal’ otherwise.…”

“…Stun quality was assessed in accordance with previous research on captive-bolt stunning of cattle [ 20 , 22 , 39 ] and a protocol adapted for the gunshot method by Schiffer et al [ 26 ]. Vital behavioural, eye-related and respiratory signs of inadequate stun ( Table 1 ) were noted directly after shooting and the behaviours were later confirmed from the video recordings.…”

“…In Germany, researchers have investigated the practical considerations and consequences for animal welfare and meat quality of using the gunshot method in small beef breeds such as Galloway and German Angus. They found that a frontal gunshot, placed correctly in the forehead from a distance of 5–15 m, causes brain damage that leads to immediate unconsciousness [ 26 ]. It was concluded that the bullet should stay in the animal’s skull to achieve a good stun and a low risk of injury to other animals or there being splinters in the carcass [ 26 ].…”

“…They found that a frontal gunshot, placed correctly in the forehead from a distance of 5–15 m, causes brain damage that leads to immediate unconsciousness [ 26 ]. It was concluded that the bullet should stay in the animal’s skull to achieve a good stun and a low risk of injury to other animals or there being splinters in the carcass [ 26 ]. The research indicated, at least in lighter beef breeds, that this is best achieved with semi-jacketed small-calibre ammunition (.22 Magnum), while larger calibres and full metal jacketed .22 Magnum ammunition tended to pass through the skull.…”