Evaluation of a breast support conveyor to improve poultry welfare on the shackle line

Decoding halal and jhatka slaughter: novel insights into welfare and protein biomarkers in slow-growing broiler chicken

BACKGROUND

The first evidence of blood biochemical and proteomic changes in slow-growing broiler chicken subjected to ritual slaughter like halal (HS) and jhatka (JS) without stunning and commercial slaughter with electrical stunning (ES) was decoded.

RESULTS

Significant stress indicators like cortisol and triiodothyronine were markedly elevated in JS birds, whereas increased (P < 0.05) levels of lactate dehydrogenase and creatine kinase were observed in JS and ES birds. Two-dimensional gel electrophoresis coupled to MALDI-TOF MS elucidated the overabundance of glyceraldehyde-3-phosphate dehydrogenase and l-lactate dehydrogenase that are positively correlated with stress in JS broilers. Bioinformatic analysis explored the multifaceted landscape of molecular functions.

CONCLUSION

The study has uncovered that ritual slaughter performed without stunning against commercial slaughter with ES practices elicit varying levels of stress as evident from blood biochemistry and novel protein markers. © 2024 Society of Chemical Industry.

Effects of preslaughter shackling on postmortem glycolysis, meat quality, changes of water distribution, and protein structures of broiler breast meat

The objective of this study was to investigate the effects of preslaughter shackling on stress, postmortem glycolysis, meat quality, water distribution, and protein structures of pectoralis majors. Before slaughter, Arbor Acres broilers (n = 105, 42 days old, 2.0 to 2.5 kg) were randomly categorized into 3 treatment groups: (I) control group without shackling (NS); (II) 2.5 min shackling (SS); (III) 4.5 min shackling (LS). Each treatment group consisted of 5 replicates with 7 broilers each. Results indicated that preslaughter shackling increased (P < 0.05) plasma corticosterone and adrenocorticotropic hormone concentrations in comparison with the control group. Antemortem shackling increased (P < 0.05) activity of glycogen phosphorylase and phosphofructokinase-1 (PFK-1) accompanying with rapid glycolysis and pH decline at early postmortem. LS treatment led to myosin denaturation, decreased (P < 0.05) α-helix content, and increased (P < 0.05) β-sheet structures proportion in the myofibrillar proteins. Furthermore, meat from LS treatment had higher (P < 0.05) lightness, redness, and poorer water-holding capacity. These results indicated that the longer shackling duration (4.5 min) increased stress and the rate of glycolysis, causing myosin denaturation and changes of the secondary structure in the myofibrillar proteins, which aggravated the deterioration of meat quality.

Slaughter of animals: poultry

The killing of poultry for human consumption (slaughtering) can take place in a slaughterhouse or during on-farm slaughter. The processes of slaughtering that were assessed, from the arrival of birds in containers until their death, were grouped into three main phases: pre-stunning (including arrival, unloading of containers from the truck, lairage, handling/removing of birds from containers); stunning (including restraint); and bleeding (including bleeding following stunning and bleeding during slaughter without stunning). Stunning methods were grouped into three categories: electrical, controlled modified atmosphere and mechanical. In total, 35 hazards were identified and characterised, most of them related to stunning and bleeding. Staff were identified as the origin of 29 hazards, and 28 hazards were attributed to the lack of appropriate skill sets needed to perform tasks or to fatigue. Corrective and preventive measures were assessed: measures to correct hazards were identified for 11 hazards, with management shown to have a crucial role in prevention. Ten welfare consequences, the birds can be exposed to during slaughter, were identified: consciousness, heat stress, cold stress, prolonged thirst, prolonged hunger, restriction of movements, pain, fear, distress and respiratory distress. Welfare consequences and relevant animal-based measures were described. Outcome tables linking hazards, welfare consequences, animal-based measures, origins, and preventive and corrective measures were developed for each process. Mitigation measures to minimise welfare consequences were also proposed.