Metabolism of broilers subjected to different lairage times at the abattoir and its relationship with broiler meat quality

Abstract

An investigation was made into the effects of different lairage times and the position of chicken crates during transport to the slaughterhouse on the biochemical and hematological profile and physical parameters of broilers, such as color and pH of their breast meat. The treatments were defined by the animals slaughtered after 0, 2, 4 and 6 hours of lairage time at the slaughterhouse, transported in crates located in the top and bottom layers of the truck. It was found that increasing the lairage time at the slaughterhouse to over two hours reduced the number of lymphocytes and increased the heterophil/lymphocyte (H/L) ratio and the basophil count in the hemogram. In addition, lactate dehydrogenase (LDH) activity and cholesterol levels increased and plasma triglyceride and glucose levels decreased. The position of the crates in the truck altered the creatine kinase (CK) activity, and the highest enzyme activity was found in birds transported in the top layer of crates in the truck. Furthermore, the long lairage time in the slaughterhouse increased the pH and the value of a* (redness value) and decreased the lightness value of breast fillets. The interaction significant between 4 and 6 hours of lairage time and the position of the crate in the top layer of the truck favored the development of dark, firm, dry (DFD) meat.Keywords: animal welfare, DFD meat, fasting, holding sheds, pre-slaughter Palavras-chave: bem-estar animal, carne DFD, galpão de espera, jejum, pré-abate RESUMO Este trabalho objetivou a avaliação dos efeitos dos diferentes tempos de espera e da posição das caixas

Effect of Pre-Slaughter Confinement Stress on Physicochemical Parameters of Chicken Meat

“…Warriss et al (17) evaluated the consequences of vibration during the transport (180 min) and found a significant reduction of pH levels in white and red chicken muscle. On the other hand, Rodrigues et al (2) determined that different lairage times (2, 4, and 6 hours) in the slaughterhouse did not affect the initial pH of chicken breast meat (P>0.05). Nannan et al (18) determined that actions like showering and ventilation before slaughtering slowed down postmortem glycolysis and prevented glycogen from breaking rapidly.…”

“…However, an improper holding period can be a major factor in lowering meat quality. Lairage periods longer than 2 or 4 h alter the metabolism, cause hyperglycemia, hypercalcemia, hyperlactatemia, hyperkalemia, hyponatremia, acidosis, severe dehydration, and modifies the physical parameters in chicken meat (2,3) . Sometimes, a continuous processing line in slaughterhouses involves a longer lairage time to maintain the animal stock before slaughtering.…”

Characterization of dorsal recumbency syndrome associated with woody breast in broiler flocks from Ontario, Canada

“…For logistic regression, AST and CK concentrations were dichotomized based on cut-off values. Specifically, AST and CK concentrations lower than 400 and 30,900, respectively, were considered normal and coded as 0 based on published reference values ( Rodrigues et al, 2017 ; Livingston et al, 2020 ), whereas greater concentrations were coded as 1. Univariable analysis was initially performed between the outcome variable and independent variables using a relaxed P value ( P = 0.2).…”

Slaughter of animals: poultry

“…Lairage for 3-4 h in a controlled lairage environment during the summer and spring is considered as necessary to reduce the thermal load of broiler chickens . In Brazil, Rodrigues et al (2017) investigated the effects of different lairage times and the position of chicken crates during transport to the slaughterhouse on the biochemical and haematological profile. They found an increase in the heterophil/lymphocyte (H/L) ratio in birds that were subjected to 6 h of lairage at the abattoir.…”

“…In Brazil, Rodrigues et al. () investigated the effects of different lairage times and the position of chicken crates during transport to the slaughterhouse on the biochemical and haematological profile. They found an increase in the heterophil/lymphocyte (H/L) ratio in birds that were subjected to 6 h of lairage at the abattoir.…”