Oliveira Steffan Edward Octávio, Gregory Neville George, Dalla Costa Filipe Antonio, Gibson Troy John, Paranhos da Costa Mateus José Rodrigues
Programa de Pós-graduação em Zootecnia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, 14.884-900 Jaboticabal, SP, Brazil; Grupo de Estudos e Pesquisas em Etologia e Ecologia Animal, Departamento de Zootecnia, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, 14.884-900 Jaboticabal, SP, Brazil.
Royal Veterinary College, University of London, London, United Kingdom.
Meat Sci. 2017 Aug;130:64-68. doi: 10.1016/j.meatsci.2017.04.007. Epub 2017 Apr 13.
The efficiency of stunning cattle was assessed in 443 animals (304 pure Zebu and 139 crossbred cattle), being mainly mature bulls and cows. Cattle were stunned using a Jarvis pneumatically powered penetrating captive bolt gun operating with low (160-175psi, N=82) and high (190psi, N=363) airline pressure, which was within the manufactures specifications. Signs of brain function and the position of the shots on the heads were recorded after stunning. Velocity of the captive bolt and its physical parameters were calculated. Cattle shot with low pressures showed more rhythmic respiration (27 vs. 8%, P<0.001), less tongue protrusion (4 vs. 12%, P=0.03) and less masseter relaxation (22 vs. 48%, P<0.001). There was an increased frequency of shots in the ideal position when cattle were shot with the low compared to high airline pressures (15.3 vs. 3.1%). Bolt velocity and its physical parameters were significantly (P<0.01) higher when using high pressure. Airline pressures below 190psi are inappropriate when shooting adult Zebu beef cattle with pneumatically powered penetrating captive bolt guns.
在443头牲畜（304头纯种泽布牛和139头杂交牛）身上评估了击晕牛的效率，这些牲畜主要是成年公牛和母牛。使用贾维斯气动穿透式栓击枪对牛进行击晕，该枪在低（160 - 175磅力/平方英寸，N = 82）和高（190磅力/平方英寸，N = 363）气压下操作，均在制造商规定范围内。击晕后记录脑功能迹象和头部射击位置。计算栓击枪的速度及其物理参数。低压射击的牛显示出更有节律的呼吸（27%对8%，P < 0.001）、较少的伸舌现象（4%对12%，P = 0.03）和较少的咬肌松弛（22%对48%，P < 0.001）。与高气压相比，低气压射击时牛在理想位置的射击频率增加（15.3%对3.1%）。使用高气压时，栓击枪的速度及其物理参数显著更高（P < 0.01）。使用气动穿透式栓击枪击晕成年泽布肉牛时，气压低于190磅力/平方英寸是不合适的。
