Effects of stunning with different carbon dioxide concentrations and exposure times on suckling lamb meat quality

Evaluation of the quality characteristics of nitrogen gas-stunned chicken meat and small intestine

This study aimed to confirm the applicability of the new nitrogen (N2) gas stunning method in the broiler slaughtering process by comparing the meat and small intestine quality following different stunning methods (electrical, carbon dioxide (CO2), N2, and halal). Four treatments were compared: (i) electrical stunning (Elec), (ii) 80% CO2 gas stunning (CO2-gas), (iii) 98% N2 gas stunning (N2-gas), and (iv) the non-stunning method (halal). N2 gas stunning (98%) and the halal method were conducted at the pilot plant abattoir of the national institute of animal science, Korea, and electrical and 80% CO2 stunning were performed on the nearest commercial slaughter house. Meat pH24h, color (lightness, redness and yellowness), proximate composition, water holding capacity (WHC), cooking loss, and Warner-Bratzler shear force (WBSF) were measured, and in the small intestine, pH24h, color, thickness, and WBSF were measured. The Elec treatment showed high lightness, yellowness, and low redness in both meat and the small intestine, indicated by a pale color; the CO2-gas treatment showed high redness, low lightness, and low yellowness, and the coloration of meat from the N2-gas treatment was intermediate between Elec and CO2-gas. For other quality traits, the N2-gas showed good results and was between Elec and CO2-gas. Additionally, severe stress (low pH in both meats), low WHC in meat, and cracked small intestine with numerous apertures were observed in the CO2-gas, and pale colored hemorrhagic breast meat was found in the Elec. Therefore, in view of animal welfare and quality traits of meat and the small intestine, 98% N2 gas can be considered in broiler stunning.

Welfare of sheep and goats during killing for purposes other than slaughter

Sheep and goats of different ages may have to be killed on-farm for purposes other than slaughter (where slaughter is defined as killing for human consumption) either individually (i.e. on-farm killing of unproductive, injured or terminally ill animals) or on a large scale (i.e. depopulation for disease control purposes and for other situations, such as environmental contamination and disaster management) outside the slaughterhouses. The purpose of this opinion was to assess the hazards and welfare consequences associated with the on-farm killing of sheep and goats. The whole killing procedure was divided into Phase 1 (pre-killing) - that included the processes (i) handling and moving the animals to the killing place and (ii) restraint of the animals before application of the killing methods and Phase 2 - that included stunning and killing of the animals. The killing methods for sheep and goats were grouped into three categories: (1) mechanical, (2) electrical and (3) lethal injection. Welfare consequences that sheep and goats may experience during each process were identified (e.g. handling stress, restriction of movements and tissue lesions during restraint) and animal-based measures (ABMs) to assess them were proposed. During application of the killing method, sheep and goats will experience pain and fear if they are ineffectively stunned or if they recover consciousness. ABMs related to the state of consciousness can be used to indirectly assess pain and fear. Flowcharts including ABMs for consciousness specific to each killing method were included in the opinion. Possible welfare hazards were identified for each process, together with their origin and related preventive and corrective measures. Outcome tables linking hazards, welfare consequences, ABMs, origins, preventive and corrective measures were developed for each process. Mitigation measures to minimise welfare consequences were proposed.

Effects of High Concentration Nitrogen Gas Stunning of Pigs on the Quality Traits of Meat and Small Intestine

The objective of present study was to investigate the feasibility of utilizing only high concentration of nitrogen gas in the stunning of pigs and its effects on the quality traits of the meat and small intestine.To conduct this experiment, three treatment groups were compared: (i) electric stunning (T1), (ii) CO2 (80%) gas stunning (T2), and (iii) N2 (98%) gas stunning (T3). A total of 21 standard pigs (Landrace × Yorkshire × Duroc; LYD) were collected from a commercial pig farm, randomly selecting seven pigs for each group (body weight of 104.5 to 120.6 kg). For stunning, each individual pig was separately kept in a gas chamber, after which each specific gas was used to fulfill the desired level in the pit. To obtain the desired level of concentration for each gas (N2 at 98% and CO2 at 80%), approximately 80 min and 35 min were required, respectively. It was observed that after reaching the desired level of concentration, pigs were stunned within a very short time (for CO2, 90 s and for N2, 120 s). For electric stunning, standard quality electric devices were used. After slaughtering, the meat and small intestine of each animal was collected separately and kept in a cool room where temperature was −2 °C. In the meat and small intestine, L* (Lightness) and b* (Yellowness) were high (p < 0.05) in the T1 and T3 groups. The T2 group showed high a* (Redness) (p < 0.05) values in both the meat and small intestine. A proximate composition of meat showed no significant differences except moisture. The water holding capacity (WHC), cooking loss (CL), and Warner-Bratzler shear force (WBSF) of meat were lowest in the T2 group, but not at a notable difference compared to T3. In the small intestine, L* (Lightness), a* (Redness), b* (Yellowness), and thickness significantly differed (p < 0.05) in each group, but WBSF showed no significance between the T2 and T3 groups. It is concluded that a high concentration of N2 gas (98%) may be considered in the stunning of pigs, and its effect on meat and small intestine is favorable.

Influence of carbon dioxide stunning procedure on quality of turkey meat

1. The objective of this study was to evaluate the effect of sex and gas stunning on quality attributes of turkey breast meat. 2. One hundred B.U.T. Premium turkeys (50 males and 50 females) were divided into four groups of 25 animals and subjected to one of two CO₂ stunning procedures: G1 stepwise (step 1: 30% CO₂, 15 s; step 2: 55% CO₂, 40 s; step 3: 70% CO₂, 45 s) or G2 fixed concentration (80% CO₂, 100 s). The pH and meat colour at 20 min post-mortem, and pH, colour (L*, a*, b*), water holding capacity (WHC), drip loss (DL), cooking loss (CL) and Warner-Bratzler shear force (WBSF) in breast samples at 24 h and 7 d post-mortem were assessed. 3. There were significant differences between stunning groups for pH, meat colour and CL, whereas no significant differences were found for DL and WBSF. Sex had a significant effect on pH and b* and ageing of meat affected pH, colour coordinates, DL and WBSF. 4. It was concluded that the G2 treatment affected negatively the pH value and colour coordinates. However, G2 stunning affected positively the WHC parameters. Female turkeys had better results than males for pH, and the colour of female turkey breast meat was less yellow than male breast meat.

Physiological responses of Manchega suckling lambs: Effect of stunning with different CO(2) concentrations and exposure times

Four groups of Manchega breed suckling lambs, stunned with different CO(2) concentrations and exposure times (G1: 80% CO(2) 90s; G2: 90% CO(2) 90s; G3: 90% CO(2) 60s; G4: 80% CO(2) 60s) plus an electrically stunned control group (G5), were used to determine (1) the physiological responses (hormonal, haematological and biochemical blood parameters) of animals after stunning and (2) the stunning effectiveness in each group. No significant differences were found among groups for hormonal levels. Within haematological parameters, significant differences among groups were only found for haemoglobin (P<0.05) and leucocytes (P<0.01), with lowest values in both groups stunned with 90% CO(2). There were significant differences between groups (P<0.01) for urea and total protein, creatinine and LDH (P<0.05; lowest and highest, respectively, for G1) and for sodium (P<0.001; lowest in G3). Stunning effectiveness was highest in G5, G3 and G1 groups and lowest in G2 and G4 (100%, 90%, 89%, 50% and 43%, respectively). According to discriminant analysis, sodium, leucocytes and creatinine marked the differences among stunning groups.