Tunnel-Ventilated Sheds with Negative Pressure Reduce Thermal Stress and Improve the Meat Quality of Broilers.

This study aimed to evaluate the thermal performance and meat quality in broilers reared in positive pressure tunnel ventilation (PP) and negative pressure tunnel ventilation (NP) in production houses. 320 Cobb broilers (40 broilers per house) were used. Pectoralis major muscles from 40 broilers (10 broilers per house) were randomly selected and analysed for L* (lightness), a* (redness), b* (yellowness), pH, drip loss (DL), cooking loss (CL) and shear force (SF). Air temperature and humidity of the transportation and slaughterhouse waiting room were recorded in the last week of rearing. Subsequently, the enthalpy comfort index (ECI) was calculated. Air temperature and ECI were higher (p < 0.05) in positive pressure sheds, whereas relative humidity was higher (p < 0.001) in negative pressure sheds. There was no statistically significant difference between the enthalpy comfort index during transport and lairage (p > 0.005). Meat quality defects (high L*, DL, CL, SF) were found in PP and NP. It was observed that b* was higher in PP, although pH and CL were higher in NP. Differences in pH, b* and CL indicate that broilers from PP had a higher level of heat stress. In conclusion, differences in pH, b*value and cooking loss in breast broilers indicate that birds in PP had a higher level of heat stress. Additional studies investigating pre-slaughter handling methods to minimise injuries and heat stress are recommended in order to improve animal welfare and meat quality.

Turkey Meat. Seasonal Effect on Meat Quality and on Dead on Arrival Index in a Commercial Plant

ABSTRACT The objective of this study was to determine the incidence of Pale, Soft, Exudative (PSE) meat and to characterize the Dark, Fim, Dry (DFD) meat as well as the Dead on Arrival (DOA) index in a commercial turkey slaughterhouse in southern Brazil during the summer and winter seasons. The journeys (n=64) were over a distance of 36 ± 20 km and took approximately 95 ± 20 min. Color (L*) and pH distribution of turkey breast meat (n=5,352) were evaluated from different farms (n=64) during the 2015-2016 years. The pH, water-holding capacity, color (L*, a*, b*) were used to establish cutoff values for DFD meat (L* < 44.0 and pH > 5.90) and presented correlation among them. The L* value was the highest during the summer (P<0.01), indicating the highest incidence of PSE meat (28.35 %), and lowest during winter, observing the highest incidence of DFD meat (10.3 %). Finally, the obtained summer DOA index was 0.23 % higher in relation to winter.

Pork: profile of the West of Paraná consumers and physical evaluation of chop / Carne suína: perfil de consumidores do Oeste do Paraná e avaliação física de bisteca

Pork consumption in Brazil is still low despite its productive importance. Relevant issues such as swine breeding, meat quality, and evaluation of aspects and attributes considered important by pork consumers at the time of purchase allows identifying consumer market demands. Moreover, physical parameters evaluation or pork cuts are suggested to certify the meat quality. The aim of this study was to identify the current situation of pig farming and determine the main aspects considered by consumers when buying pork in the Western region of Paraná state, Brazil. Furthermore, the physical properties of five pork chop brands marketed in the region were determined. Initially, an exploratory research was conducted involving ten pig farming sector professionals. This research allowed identifying that professionals understand the factors affecting meat quality and that some municipalities in the region are beyond their absorption capacity for pig production market. A descriptive research involving one hundred pork consumers showed that, although most prefer beef, 41% reported to consume pork 2 to 3 times a week. Pork chops and ribs are the preferred cuts, either fried or roasted. Details such as expiration date and federal inspection register were considered the most important aspects at the time of purchase, while price was the least important one. The meat color was the most mentioned sensory attribute. The physical analyses of five pork chop brands showed no pH difference (p > 0.05), water holding capacity, and cooking loss results, distinctive from the one observed for color (L*, a* and b*) and shearing force, which showed differences among the brands (p ≤ 0.05). Comparing pH and L*, it can be suggested that two brands showed normal meat characteristics, one DFD meat (pH > 6.0 and L* < 45), and other two brands PSE (pH < 5.8 and L* > 50).(AU)

O consumo de carne suína no Brasil ainda é baixo, apesar da importância produtiva. Questões relevantes a suinocultura, qualidade da carne e avaliação de aspectos e atributos considerados importantes por consumidores no momento da compra possibilitam identificar a demanda do mercado consumidor. Além disso, a avaliação dos parâmetros físicos de cortes é sugerida para atestar a qualidade. Este trabalho teve como objetivo identificar a situação atual da suinocultura e determinar os principais aspectos e atributos considerados pelos consumidores no momento da compra de carne suína na região Oeste do Paraná. De forma adicional, os parâmetros físicos de cinco marcas de bistecas suínas comercializadas na região foram determinados. Inicialmente, uma pesquisa exploratória foi realizada com dez profissionais do setor suinícola, que demonstraram conhecer os fatores que interferem na qualidade da carne obtida e que algumas cidades da região estão ultrapassando a capacidade de absorção do mercado de produção de suínos. Uma pesquisa descritiva com cem consumidores mostrou que apesar de a maioria preferir carne bovina, 41% declararam consumir carne suína de 2 a 3 vezes por semana. Os cortes preferidos foram bisteca e costela, consumidos na maioria das vezes fritos ou assados. Itens como validade e registro de inspeção federal foram considerados os de maior importância no ato da compra enquanto o preço foi o menos importante.(AU)

Pork: profile of the West of Paraná consumers and physical evaluation of chop / Carne suína: perfil de consumidores do Oeste do Paraná e avaliação física de bisteca

Pork consumption in Brazil is still low despite its productive importance. Relevant issues such as swine breeding, meat quality, and evaluation of aspects and attributes considered important by pork consumers at the time of purchase allows identifying consumer market demands. Moreover, physical parameters evaluation or pork cuts are suggested to certify the meat quality. The aim of this study was to identify the current situation of pig farming and determine the main aspects considered by consumers when buying pork in the Western region of Paraná state, Brazil. Furthermore, the physical properties of five pork chop brands marketed in the region were determined. Initially, an exploratory research was conducted involving ten pig farming sector professionals. This research allowed identifying that professionals understand the factors affecting meat quality and that some municipalities in the region are beyond their absorption capacity for pig production market. A descriptive research involving one hundred pork consumers showed that, although most prefer beef, 41% reported to consume pork 2 to 3 times a week. Pork chops and ribs are the preferred cuts, either fried or roasted. Details such as expiration date and federal inspection register were considered the most important aspects at the time of purchase, while price was the least important one. The meat color was the most mentioned sensory attribute. The physical analyses of five pork chop brands showed no pH difference (p > 0.05), water holding capacity, and cooking loss results, distinctive from the one observed for color (L*, a* and b*) and shearing force, which showed differences among the brands (p ≤ 0.05). Comparing pH and L*, it can be suggested that two brands showed normal meat characteristics, one DFD meat (pH > 6.0 and L* 50).

O consumo de carne suína no Brasil ainda é baixo, apesar da importância produtiva. Questões relevantes a suinocultura, qualidade da carne e avaliação de aspectos e atributos considerados importantes por consumidores no momento da compra possibilitam identificar a demanda do mercado consumidor. Além disso, a avaliação dos parâmetros físicos de cortes é sugerida para atestar a qualidade. Este trabalho teve como objetivo identificar a situação atual da suinocultura e determinar os principais aspectos e atributos considerados pelos consumidores no momento da compra de carne suína na região Oeste do Paraná. De forma adicional, os parâmetros físicos de cinco marcas de bistecas suínas comercializadas na região foram determinados. Inicialmente, uma pesquisa exploratória foi realizada com dez profissionais do setor suinícola, que demonstraram conhecer os fatores que interferem na qualidade da carne obtida e que algumas cidades da região estão ultrapassando a capacidade de absorção do mercado de produção de suínos. Uma pesquisa descritiva com cem consumidores mostrou que apesar de a maioria preferir carne bovina, 41% declararam consumir carne suína de 2 a 3 vezes por semana. Os cortes preferidos foram bisteca e costela, consumidos na maioria das vezes fritos ou assados. Itens como validade e registro de inspeção federal foram considerados os de maior importância no ato da compra enquanto o preço foi o menos importante.

Underlying connections between the redox system imbalance, protein oxidation and impaired quality traits in pale, soft and exudative (PSE) poultry meat.

The connections between the redox imbalance in post-mortem muscle, early protein oxidation and the onset of pale, soft and exudative (PSE) condition in chicken breast are studied. PSE was induced by incubation of post-mortem chicken carcasses at 37°C for 200min. PSE-induced muscle consistently had faster pH decline and lower pH at 200min (5.84 vs. 6.59) and 24h (5.69 vs. 5.96), higher L(∗) (54.4 vs. 57.3), and lower texture and water holding capacity (WHC) than normal meat. The activities of catalase, glutathione peroxidase and superoxide dismutase were significantly lower in PSE-induced samples than in the normal counterparts. PSE was more susceptible to proteolysis and protein oxidation than normal meat during succeeding chilled storage with more intense tryptophan and thiols depletion, higher protein carbonylation and more intense formation of protein cross-links. We provide plausible explanations to support the role of protein oxidation in the impaired quality PSE chicken.

Cyclic heat stress in broilers and their effects on quality of chicken breast meat

Background: The growing concern of the effects of high temperatures in the production of broilers, apart from the consistent increase of the consumption of chicken meat in Brazil and in the world and form the demands of consumers and industries increase the need for comprehensive studies on organoleptic characteristics of this meat, such as color and loss of water drip (drip loss). In this scenario, the objective of this research was to investigate the effects of cyclic heat stress on color and drip loss of chicken breast of broilers at different growth stages.Materials, Methods & Results: A group of 840 1-day-old CobbAvian48® broiler male chicks was housed in a shed, in 24 boxes with 35 birds each according to a completely randomized design. The broilers were reared under thermal comfort for 15 days. On the 16th day the shed was divided in sections with the following thermal environments: Control - Broilers reared under natural temperature and humidity conditions between day 16 and 42 (C 16-42), and broilers submitted to cyclic heat stress between day 16 and 21 (CHS 16-21), day 22 and 42 (CHS 22-42), and between day 16 and 42 (CHS 16-42). Stress was imposed from 12:00 noon to 1:00 pm, with temperature above the maximum recommended for the lineage. On day 42, one broiler of each box weighing close to the mean weight on a box basis was slaughtered and the breast meat removed, totaling 24 breasts. Color was analyzed using the following visual standard: 1 = PSE meat (pale, soft, exudative), 2 = normal meat, and 3 = DFD meat (dark, firm, dry). Chicken breasts were visually compared to the standard. To determine drip loss, a meat fragment was removed, weighed, and placed in a nylon-poly plastic bag, which in turn was placed in polyethylene plastic packaging properly labeled. After, these were hung in a refrigerator for 48 h at controlled temperature of 4-8°C. Drip loss data were analyzed using ANOVA, and the means were compared using the Tukey test at 5%.[...]

Cyclic heat stress in broilers and their effects on quality of chicken breast meat

Background: The growing concern of the effects of high temperatures in the production of broilers, apart from the consistent increase of the consumption of chicken meat in Brazil and in the world and form the demands of consumers and industries increase the need for comprehensive studies on organoleptic characteristics of this meat, such as color and loss of water drip (drip loss). In this scenario, the objective of this research was to investigate the effects of cyclic heat stress on color and drip loss of chicken breast of broilers at different growth stages.Materials, Methods & Results: A group of 840 1-day-old CobbAvian48® broiler male chicks was housed in a shed, in 24 boxes with 35 birds each according to a completely randomized design. The broilers were reared under thermal comfort for 15 days. On the 16th day the shed was divided in sections with the following thermal environments: Control - Broilers reared under natural temperature and humidity conditions between day 16 and 42 (C 16-42), and broilers submitted to cyclic heat stress between day 16 and 21 (CHS 16-21), day 22 and 42 (CHS 22-42), and between day 16 and 42 (CHS 16-42). Stress was imposed from 12:00 noon to 1:00 pm, with temperature above the maximum recommended for the lineage. On day 42, one broiler of each box weighing close to the mean weight on a box basis was slaughtered and the breast meat removed, totaling 24 breasts. Color was analyzed using the following visual standard: 1 = PSE meat (pale, soft, exudative), 2 = normal meat, and 3 = DFD meat (dark, firm, dry). Chicken breasts were visually compared to the standard. To determine drip loss, a meat fragment was removed, weighed, and placed in a nylon-poly plastic bag, which in turn was placed in polyethylene plastic packaging properly labeled. After, these were hung in a refrigerator for 48 h at controlled temperature of 4-8°C. Drip loss data were analyzed using ANOVA, and the means were compared using the Tukey test at 5%.[...](AU)

Commercial preslaughter blue light ambience for controlling broiler stress and meat qualities

The objective of this work was to study the effect of blue light diffuser on the broiler stress control by measuring the occurrence of PSE meat just before slaughtering. Birds were divided into the following two groups before slaughter at the point of being hung on shackles: broiler group under low intensity blue light ambience (475, 17-20 lx) and control group under white light (550-650nm, 321-332 lx). Birds' stressful conditions were measured by the occurrence of PSE meat. Breast fillets were classified as PSE meat based on pH (<5.8) and lightness (L*> 53.0). The fillet samples in the control group had the following characteristics: pHu=5.77, L* = 54.26 and b*= 6.27. The fillet samples from birds under blue light ambience had the following characteristics: pHu=5.81, L* = 52.86 and b* = 5.22 (p < 0.05). These results revealed that the treatment of blue light ambience just before slaughtering contributed to the alleviation of ante mortem stress of the birds, which was observed by a 14% decrease in the occurrence of PSE meat. Exposure to blue light just before slaughtering was shown to have potential to be used in modern slaughterhouses to offer a comfortable atmosphere, thereby maintaining breast meat quality.

Evaluation of halothane as stressor agent in poultry / Avaliação do halotano como agente estressor em frangos

Studies have been demonstrating in poultry, the existence of at least two causes for the formation of PSE meat: genetic through the sensibility towards halothane and the environmental factor in particular the temperature as the main factor. Thus the objective of this work was to evaluate halothane as stressor agent for broiler concomitantly to evaluating the PSE incidence by submitting these birds to thermal stress. In this experiment, 24 broilers of commercial lineage were divided in 6 animals for 4 treatments: HHH, broilers submitted to halothane test and slaughtered 1h after this test; HET broilers submitted to halothane at 35°C/1h after 48h of halothane test followed by the birds slaughtering; EET, broilers submitted to thermal stress and slaughtered immediately after this treatment, and finally the control treatment (CCC) where broilers were not submitted to halothane test nor to thermal stress as control. The initial pH of Pectoralis major m, was evaluated 30 min post mortem and the pH final, color, (L*, a*, b*) water holding capacity (WHC), and R value analysis were carried out after 24h of storage of fillet samples at 40C. The pH24h was higher (p ≤ 0.05) for CCC samples in comparison to other treatments and R value was higher for birds under HET and EET treatments in comparison to CCC (p ≤ 0.05) suggesting that the rigor mortis was more rapid in samples from birds submitted to thermal stress. The HHH, HET, and EET treatments presented 4 birds each with PSE meat and 2 broilers from CCC treatment originated PSE meat showing the influence not only halothane but also the thermal stress over broilers welfare. Finally, results demonstrated that halothane is a stressor agent as well as the thermal stress and both promoted dramatic biochemical changes bringing about the formation of broiler PSE meat.

Resultados vêm mostrando uma direta relação entre a sensibilidade ao halotano e a ocorrência de filés PSE em aves, que pode ser originado pela influência de fatores ambientais, em que a temperatura é o principal fator. Assim, o objetivo do trabalho foi avaliar o halotano como agente estressor em frangos concomitantemente ao estresse térmico. Neste experimento, 24 frangos de linhagem comercial foram divididos em 6 animais para 4 tratamentos: HHH, frangos submetidos ao teste do halotano e abatidos 1h após o teste; HET, frangos submetidos ao teste do halotano e, 48h depois, ao estresse de 35°C por 1h, sendo abatidos em seguida; EET, frangos submetidos ao estresse térmico e abatidos imediatamente após este tratamento; e finalmente o tratamento Controle (CCC), em que os frangos não foram submetidos ao teste do halotano e nem ao estresse térmico. O pH inicial do músculo Pectoralis major m e o valor de R foram medidos aproximadamente 30 min post mortem e as análises de pH final, cor (L*, a*, b*), Capacidade de Retenção de Água (CRA) foram realizadas 24h após o abate nos filés mantidos a 40C. O valor de pH24h foi maior (p ≤ 0,05) para os filés do CCC em comparação aos demais tratamentos e o valor de R foi maior para as aves HET e EET em comparação ao CCC (p ≤ 0,05) sugerindo que o rigor mortis foi instalado mais rapidamente nas amostras derivadas das aves submetidas ao estresse térmico. Os tratamentos HHH, HET e EET apresentaram 4 aves cada com carnes PSE e 2 aves do tratamento CCC originaram filés PSE, demonstrando uma interferência tanto do halotano quanto do estresse térmico sobre o bem-estar das aves. Assim, os resultados demonstram que o halotano mostrou ser um agente estressor desencadeando alterações bioquímicas nos músculos das aves semelhantes às desencadeadas pelo estresse térmico pré-abate.

Evaluation of halothane as stressor agent in poultry / Avaliação do halotano como agente estressor em frangos

Studies have been demonstrating in poultry, the existence of at least two causes for the formation of PSE meat: genetic through the sensibility towards halothane and the environmental factor in particular the temperature as the main factor. Thus the objective of this work was to evaluate halothane as stressor agent for broiler concomitantly to evaluating the PSE incidence by submitting these birds to thermal stress. In this experiment, 24 broilers of commercial lineage were divided in 6 animals for 4 treatments: HHH, broilers submitted to halothane test and slaughtered 1h after this test; HET broilers submitted to halothane at 35C/1h after 48h of halothane test followed by the birds slaughtering; EET, broilers submitted to thermal stress and slaughtered immediately after this treatment, and finally the control treatment (CCC) where broilers were not submitted to halothane test nor to thermal stress as control. The initial pH of Pectoralis major m, was evaluated 30 min post mortem and the pH final, color, (L*, a*, b*) water holding capacity (WHC), and R value analysis were carried out after 24h of storage of fillet samples at 40C. The pH24h was higher (p ? 0.05) for CCC samples in comparison to other treatments and R value was higher for birds under HET and EET treatments in comparison to CCC (p ? 0.05) suggesting that the rigor mortis was more rapid in samples from birds submi

Resultados vêm mostrando uma direta relação entre a sensibilidade ao halotano e a ocorrência de filés PSE em aves, que pode ser originado pela influência de fatores ambientais, em que a temperatura é o principal fator. Assim, o objetivo do trabalho foi avaliar o halotano como agente estressor em frangos concomitantemente ao estresse térmico. Neste experimento, 24 frangos de linhagem comercial foram divididos em 6 animais para 4 tratamentos: HHH, frangos submetidos ao teste do halotano e abatidos 1h após o teste; HET, frangos submetidos ao teste do halotano e, 48h depois, ao estresse de 35C por 1h, sendo abatidos em seguida; EET, frangos submetidos ao estresse térmico e abatidos imediatamente após este tratamento; e finalmente o tratamento Controle (CCC), em que os frangos não foram submetidos ao teste do halotano e nem ao estresse térmico. O pH inicial do músculo Pectoralis major m e o valor de R foram medidos aproximadamente 30 min post mortem e as análises de pH final, cor (L*, a*, b*), Capacidade de Retenção de Água (CRA) foram realizadas 24h após o abate nos filés mantidos a 40C. O valor de pH24h foi maior (p ? 0,05) para os filés do CCC em comparação aos demais tratamentos e o valor de R foi maior para as aves HET e EET em comparação ao CCC (p ? 0,05) sugerindo que o rigor mortis foi instalado mais rapidamente nas amostras derivadas das aves submetidas ao estresse térmico

Lipid oxidation and fatty acid profile related to broiler breast meat color abnormalities

The aim of this work was to study the influence of lipid oxidation on broiler breast meat (Pectoralis major m) color abnormalities. There were 27.0 percent more lipid oxidation in PSE in relation to normal meat and 41.0 percent more in relation to DFD-like meat (p<0.05). The fatty acid profile was also significantly different since the arachidonic acid (AA) fraction increased 38.6 and 70.5 percent in PSE meat comparing to normal and DFD-like meats, respectively. The ratio PUFA/SFA changed in these three types of meat: 0.736, 0.713 and 0.694 for PSE, normal and DFD-like meat respectively, reflecting the highest production of polyunsaturated fatty acids in the PSE meat samples. Results indicated that phospholipase A2 enzyme activities played a relevant role towards the development of PSE-meat syndrome in a cascade of biochemical reactions promoting the formation of free radicals from AA, which ultimately damaged the muscle membrane systems.

A influência da oxidação lipídica no surgimento das anormalidades das cores do filé do peito de frango (Pectoralis major) foi avaliado. A oxidação lipídica foi 27 por cento maior em carnes PSE em relação ao normal e 41,0 por cento em relação ao análogo DFD (p< 0.05). O perfil dos ácidos graxos foi também significantemente diferente desde que a fração do ácido araquidônico (AA) aumentou 38,6 por cento e 70,5 por cento em carnes PSE em comparação às carnes normais e análogas ao DFD, respectivamente. A razão PUFA/SFA se alterou nos três tipos de carne, 0,736, 0,713 e 0,694 para carnes PSE, normal e análogo ao DFD, respectivamente, refletindo a maior produção dos ácidos graxos polinsaturados em amostras PSE. Esses resultados corroboram os nossos anteriores, indicando que a atividade da enzima fosfolipase A2 tem um papel relevante no desenvolvimento da síndrome do PSE em uma cascata de reações bioquímicas promovendo a formação dos compostos radicais livres do AA que finalmente compromete os sistemas das membranas celulares do músculo.

The effect of management of transport and lairage conditions on broiler chicken breast meat quality and DOA (Death on Arrival)

The aim of this work was to evaluate the influence of time of broiler chicken transportation and lairage prior to slaughtering on the occurrence of PSE (Pale, Soft, Exudative) meat and Death On Arrival (DOA) under non-commercial conditions in the Brazilian summer. Male birds (n=250) from a commercial line were subjected to different periods of journey (30, 90, and 180 min) and lairage (0, 90, and 180 min) before slaughtering. The occurrence of PSE was higher in broilers subjected to shorter journeys and lairage periods, whereas DOA was more pronounced upon longer periods of transport and lairage. The DOA occurrence percentage was much higher in comparison to commercially available figures, confirming that broiler chickens are very sensitive to both transport and lairage maneuvers.

O objetivo desse trabalho foi avaliar a influência do tempo de transporte e período de descanso antes do abate dos frangos na ocorrência das carnes PSE (Pale, Soft, Exudative: Pálido, Amolecido e Exsudativo) e DOA (Dead On Arrival: Morte Na Chegada) nas condições não comerciais durante o verão brasileiro. Frangos machos (n=250) de uma linhagem comercial foram submetidos a diferentes periodos de jornada (30, 90 e 180 min) e descanso (0, 90 e 180 min) antes do abate. A ocorrência do PSE foi maior em frangos submetidos tanto em tempos para as viagens curtas como para o de descanso enquanto que DOA foi mais pronunciada em condições de jornadas longas e maior periodo de descanso. A porcentagem da ocorrência do DOA foi maior ao se comparar com os resultados obtidas por empresas comerciais confirmando que os frangos são sensiveis às condições das viagens e de descanso a que são submetidos.