Potential predisposing factors for ecchymosis in the intercostal muscles of sheep carcases in South Australia

Context Ecchymosis is an undesirable appearance in meat caused by small bleeds from capillaries broken during the slaughter process. These lesions are heavily trimmed during processing, incurring labour costs and yield losses. Aims To estimate the prevalence of ecchymosis in a South Australian abattoir and investigate potential predisposing factors. Methods A generalised linear mixed model estimated the effects of breed, age, slaughter shift (morning or afternoon), kill date, direct or market consignment, hot standard carcase weight (HSCW, kg), deviation from lot average carcase weight (ZHSCW, standard units), palpated fat score (mm) and time in lairage (h) on the prevalence of ecchymosis. Over 7 days, 12286 lamb and 3802 mutton carcases from 82 properties were scored (0, 1) for ecchymosis. Key results Lambs had a higher prevalence of ecchymosis (14%) than did mutton (1%; P < 0.001), with significant variation between lines of lambs (P < 0.001). Considering lambs only, kill date (P < 0.01), time in lairage (P < 0.001), and the quadratic terms of HSCW (P < 0.001) and ZHSCW (P < 0.01) affected the prevalence of ecchymosis. Conclusions Ecchymosis had a significant prevalence in lambs only. The time lambs spend in lairage and their bodyweight may be predisposing factors for ecchymosis before slaughter and warrant further investigation. Implications The interaction of size and weight extremeness appeared to predispose lambs to developing ecchymosis at slaughter. Farm of origin was another identified risk factor (management group). Whether it was size and extremeness influencing body composition or other mechanisms involved in vascular integrity, is not known. Further research is required to identify these mechanisms so as to establish breeding and management guidelines that will decrease the likelihood and cost of ecchymosis in lambs. Ecchymosis remains poorly understood, but fractured capillaries indicate a weakness in vascular tissue. Given the present study included over 12000 observations in 7 days, ecchymosis in lambs could be used as a model to study vascular weakness in humans.

Livestock Handling at the Abattoir: Effects on Welfare and Meat Quality

Low-stress handling that uses behavioral principles can help reduce bruises and improve meat quality in cattle, pigs, and sheep. Short-term stressors before stunning, such as electric prod use or jamming in the race, may increase Pale, Soft, Exudative meat in pork and reduce tenderness in beef. Longer term stresses may increase Dark, Firm and Dry meat. Continuous assessment of livestock handling practices is recommended. Handlers should be trained to move small groups of livestock. They also need to understand behavioral principles. The most important ones are flight zone and the point of balance at the shoulder. Calm animals will be easier to handle. Simple economical improvements in races and lairages can help facilitate animal movement through the facility. The movement of livestock can often be improved by (1) installation of a light at a dark stun box entrance, (2) moving lamps to reduce reflections on shiny metal, (3) installation of solid shields to prevent incoming animals from seeing people on moving conveyors, (4) redirection of air flow at the stun box entrance, or (5) in elevated conveyor restrainers, use of a false floor to prevent entering animals from seeing the “visual cliff ” effect. Continuous assessment and supervision are required to maintain low-stress handling methods.

Head current during and blood splashes after electrical stunning in relation to characteristics of the pig's body

In order to evaluate electrical stunning in relation to the incidence of blood splashes, meat quality and carcass quality parameters, 2035 pigs, heterozygous for the halothane gene, were observed during slaughter at a commercial slaughterhouse. The head current during electrical stunning is significantly higher (P<0.01) in gilts with a lower live weight (P<0.0001) or cold carcass weight (P<0.0001) and a higher lean meat percentage (P<0.0001). Also the incidence of blood splashes in the ham is significantly higher in gilts (P<0.0001) with a higher lean meat percentage (P=0.0028; odds ratio=1.11), a lower live weight (P=0.003; odds ratio=0.98) and a lower type number (P=0.0074; odds ratio=0.64). For barrows, no significant parameters were revealed. These results suggest that the variability in incidence of blood splashes can be explained by the variability of current density depending both on sex and body characteristics. Thus, electrical stunning can be improved by providing an energy level, based on the body characteristics of the pig.

The effects of alternative electrical and mechanical stunning methods on hemorrhaging and meat quality of broiler breast and thigh muscles

Five trials were conducted to determine the effects of various alternative stunning and restraining methods on the quality of chicken broiler meat. The stunning methods used were electrical whole-body and head-only stunning with different voltages (25 vs 100 V) and frequencies (50 vs 200 Hz), and mechanical captive bolt stunning. Before being stunned, the broilers were restrained either by shackling them by the feet, restraining their heads while they were standing, or placing them in a cone. Convulsions during and after stunning were subjectively scored. At 1 d post-mortem, the pH, color, and the intensity and number of hemorrhages, of breast and thigh muscles were measured. Convulsions were, in order of increasing intensity, observed after whole-body stunning using 50 Hz, whole-body stunning using 200 Hz, head-only stunning, and captive bolt stunning. No differences in ultimate pH were measured. A consistent difference in color was observed between whole-body and head-only stunning. Head-only stunning resulted in darker and more red (P < or = 0.01) breast muscles. Head-only and captive bolt stunning resulted in hemorrhages that were located more distal in the breast muscle than those observed after whole-body stunning. Captive bolt stunning (in a cone) resulted in fewer (P < or = 0.01) hemorrhages in breast and thigh muscles than whole-body stunning (100 V, 50 Hz, shackled), and in a similar level of hemorrhaging as electrical head-only stunning (25 V, 200 Hz, in a cone).