The objective of this work was to investigate the influence of water spray treatment before broiler slaughtering on the quality of breast meat (Pectoralis major) and to observe ultrastructural changes promoted by the biochemical/physiological events during rigor mortis onset. Commercial Ross chickens were divided into two groups: Untreated Group (UG) (n = 608) and Treated Group (TG) (n = 611), without and with water shower treatment, respectively. Drip and cook losses, pH and color measured after 24 h postmortem demonstrated that antemortem water shower treatment inhibited PSE development in chicken breast meat. Histological studies of the PSE samples from UG birds after 72 h postmortem revealed under light microscopy a shrinking of muscle cell diameter by approximately 10% in relation to TG samples and an extracellular enlargement of endomysium and perimysium sheaths. By electron microscopy of PSE meat, Z‐lines appeared fragmented, A‐bands including the M‐line disappeared and a super‐contraction of sarcomeres was observed, indicating that proteins were adversely affected by heat stress.

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A necessidade para uma maior produção de carne magra em suínos tem acarretado modificações nas características bioquímicas do músculo conduzindo ao desenvolvimento das anomalias nas suas cores, as denominadas carnes PSE e DFD. Estas carnes por apresentarem alterações de suas propriedades funcionais, resultam em grandes perdas econômicas. Nesse experimento, foram utilizadas 946 amostras de Longissimus dorsi m., lombos de suínos da linhagem Dalland, machos castrados e fêmeas, com 100 dias de idade, em um Frigorífico localizado na Região Sul do País. Os lombos foram classificados com base no valor de L* 24 h e pH 24 h. Foi constatada uma incidência de 22,8% de carnes PSE, 1,0% de DFD e 76,2% de normal. Esses valores relativamente altos de carnes PSE mostram a necessidade de se realizar controles no seu manejo pré e pós-abate para a manutenção da qualidade da carne e evitar o excessivo prejuízo econômico dos frigoríficos decorrentes dessas anormalidades. Palavras-chave: cor; pH; Longissimus dorsi m.; manejo pré e pós-abate. AbstractThe needs of higher production of low fat pork have conducted changes on the muscle biochemical characteristics leading to color abnormality producing so-called PSE and DFD meats. The consequence is a relevant economical loss due to the impairment of meat functional properties. In this experiment, 946 samples of Longissimus dorsi m. from barrows and gilts of Dalland lineage, of 100 days of age, were evaluated in a pork abattoir located in the south of Brazil. Samples were classified based on the L* 24 h e pH 24 h values. Results showed the occurrence of 22.8% of PSE meat, 1.0% de DFD meat and 76.2% of normal meat. These relatively higher values for PSE show undoubtedly the needs to carry out pre-and post-mortem management in order to maintain meat quality thus avoiding the excessive economic cost due to these meat abnormalities. Keywords: color; pH; Longissimus dorsi; ante-and post-mortem management.Carnes PSE (Pale, Soft, Exudative) Na década de 1960, por exigência do consumidor, houve o direcionamento da produção de suínos para um aumento na produção de carne magra acarretando modificações substanciais tanto na composição proximal como nas características bioquímicas do músculo. Posteriormente, constataram-se que essas alterações foram provocadas por uma mutação genética na proteína reguladora do fluxo de cálcio, rianodina, provocando o surgimento do PSS (sigla inglesa de Pork Stress Syndrome) ou Síndrome do Estresse Suíno com o conseqüente comprometimento na qualidade pela formação das carnes PSE (sigla inglesa de Pale, Soft e Exudative), o que significa Pálida, Macia e Exsudativa. Estas carnes apresentam variações em suas colorações e alterações de suas propriedades funcionais, sendo um dos maiores problemas enfrentados pela indústria processadora, com conseqüentes perdas econômicas calculadas, preliminarmente, em cerca de US$ 4,5 mi 15. MURRAY e JOHNSON 14 relataram que cada chuleta de carne suína PSE perde aproximadamente 3% mais água do que a carne normal na embalagem no varejo, ...

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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.

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BackgroundThe poultry industry suffers losses from problems as pale, soft and exudative (PSE), and dark, firm and dry (DFD) meat can develop in meat as a result of short- and long-term stress, respectively. These abnormalities are impacted by pre-slaughter animal welfare.MethodsThis work evaluated the effects of open vehicle container microclimate, throughout the 38 ± 10 km journey from the farm to the slaughterhouse, on commercially turkey transported during the Brazilian winter season. The journey was initiated immediately after water bath in truck fitted with portable Kestrel anemometers to measure air ventilation, relative humidity, temperature and ventilation.ResultsThe inferior compartments of the middle and rear truck regions showed highest temperature and relative humidity, and lower air ventilation. In addition, the superior compartments of the front truck regions presented lower temperature and wind chill, and highest air ventilation. The breast meat samples from animals located at the inferior compartments of the middle and rear truck regions and subjected to with water bath (WiB) treatment presented highest DFD-like and had lowest PSE-like meat incidence than those from animals located at other compartments within the container. Lower incidence of PSE-like meat was observed in birds without water bath (WoB).ConclusionsAssessment on turkeys transported under Brazilian southern winter conditions revealed that breast meat quality can be affected by relative humidity, air ventilation, temperature, and transport under subtropical conditions promoting color abnormalities and the formation of simultaneously PSE-like and DFD-like meat.

This study evaluated the formed microclimate commercial truck transport practices effects on the turkeys' welfare by measuring Dead on Arrival (DOA) index and pale, soft, and exudative (PSE-like) meat occurrence. The experimental design was entirely randomized in a 6 × 2 factorial arrangements (two truck container compartments × six water shower groups) with birds positioned at superior front (SF), inferior front (IF), superior middle (SM), inferior middle (IM), superior rear (SR), and inferior rear (IR) and two bath treatments: with water shower (WiS) and without water shower (WoS) with eight replications for each treatment. The animals were transported for 95 min' journey from the farm to the slaughterhouse under hot-humidity conditions. The results shown herein indicated the formation of a thermal core at the inferior middle and rear truck container regions, because the heat produced by the birds and the influence of developed microclimate consisting of temperature, relative humidity, and air ventilation. The IM and IR container compartments under the WoS treatment presented the highest (P < 0.01) numbers of PSE-like meat incidence and DOA index values compared with those located at the front under WiS treatment as the consequence of the altered to birds unbearable conditions within the container microclimate in transit. The formed microclimate during the commercial transport practices under hot-humidity conditions affected the bird's welfare consequently turkey meat qualities.