Effect of different levels of sodium in water on performance, carcass yield, and meat quality of slow-growing chickens.

The aim of this study was to evaluate the effects of sodium (Na) levels in the drinking water on the performance, carcass yield, and meat quality of slow-growing chickens. A completely randomized design with 4 treatments (4.90; 32.30; 60.53; and 101.0 mg/L of Na in water) and 6 replications, with 20 birds per experimental unit, was adopted. The treatments are evaluated in the following: 10 to 25, 10 to 39, and 10 to 54 days. For slow-growing chickens from 10 to 25 days, the Na levels in the drinking water promoted a quadratic effect for water and feed intake (p<0.05). The inclusion of Na in the drinking water offered to slow-growing chickens from 10 to 39 days resulted in a reduction in voluntary water intake (p<0.05). For slow-growing chickens from 10 to 54 days, the Na levels in the drinking water promoted a quadratic effect for water intake and feed conversion (p<0.05). After 54 days, the slow-growing chickens were slaughtered and it was observed that the Na inclusion in the drinking water offered to slow-growing chickens provided a quadratic effect for cold carcass, breast, and kidney weights and for kidney and liver yields (p<0.05). Liver weight was reduced with increasing Na levels in the drinking water (p<0.05). For the breast cut, the Na levels in the drinking water promoted a quadratic effect for pH24h, drip loss, cooking loss, protein, and fat and an increase in shear force (p<0.05). For the thigh cut, the Na levels in the drinking water increased the pH24h and reduced drip loss and shear force (p<0.05), and a quadratic effect was observed for moisture and fat (p<0.05). Levels of up to 60.53 mg/L of Na promote an increase in feed intake, which provided a higher breast weight and protein content with reduced fat and drip loss.

Classification accuracy of different pork quality evaluation methods in assessment of meat with lowered drip loss / Precisão da classificação de métodos de avaliação da qualidade da carne suína para menor perda durante o gotejamento

This study compared the diagnostic value of pork quality evaluation methods using different pH threshold values and time-points with muscle metabolites concentration threshold values measured 45 min. post mortem in assessment of meat with lowered drip loss. Samples of 100 longissimus dorsi (LD) (Landrace × Yorkshire) × Duroc fatteners were examined after slaughter for following parameters: muscle acidity in 35 min, 2 h, 3 h, 24 h and 48 h (pH1, pH2, pH3, pH24 and pH48), colour lightness (L*, a*, b*), meat yield after curing and thermal processing in 72 °C (technological yield), water-holding capacity (WHC) and drip loss in 48, 96 and 144 h (DL48, DL96, DL144). To verify the accuracy of analysed methods two groups were distinguished according to DL48, e.g. Low DL (DL48≤4%) and High DL (DL48>4%). In High DL pH1 to pH48 were statistically lower while L*, WHC, DL48, DL96, DL144 were statistically higher (P≤0.05). On the basis of pH-dependent methods classification to RFN (red, firm, normal), PSE (pale, soft, exudative), DFD (dark, firm, dry) and AM (acid meat) was performed and then the percentage share of Low DL and High DL among meat classified as RFN was evaluated. Despite most samples were classified as RFN Low DL share among them did not exceed 50%. If meat sample shows metabolites concentration below threshold value and was assigned to Low DL (or was assigned to High DL above threshold value) it was regarded as correctly classified. The most promising cut-off point (correct classification of 73%) was 45 µmol both for glycogen and lactate.(AU)

Neste estudo foram analisadas 100 amostras de longissimus dorsi (LD) de suinos Landrace, Yorkshire (L × Y) × Duroc (D). Dois grupos foram distinguidos de acordo com a perda por gotejamento medida 48 horas após o abate, por ex. DL baixo (DL48≤%) e DL alto (DL48> 4%). Em DL alto maior leveza (L*), capacidade de retenção de água (WHC), perda por gotejamento em 48 (DL48), 96 (DL96), 144 (DL144) e menor acidez muscular de 35 min. a 48 horas post mortem (pH1 a pH48) foram anotados (P≤0.01). A baixa participação de DL dentro das amostras classificadas como RFN (vermelha, firme, normal) com base em vários métodos de avaliação da qualidade da carne suína usando diferentes pontos de tempo de pH e valores de limiar não excederam 50%. A tentativa de uso de várias concentrações de metabólitos musculares mediu 45 min. post mortem (glicogênio, lactato e suas combinações) como valores limiares na avaliação de DL baixo e DL alto foi então realizado. Os pontos de corte mais promissores (45 µmol por g de tecido muscular tanto para glicogênio quanto para lactato) permitiram classificar corretamente 83.82% de DL baixo e 50% de DL alto respectivamente abaixo e acima deles.(AU)

Classification accuracy of different pork quality evaluation methods in assessment of meat with lowered drip loss / Precisão da classificação de métodos de avaliação da qualidade da carne suína para menor perda durante o gotejamento

ABSTRACT: This study compared the diagnostic value of pork quality evaluation methods using different pH threshold values and time-points with muscle metabolites concentration threshold values measured 45 min. post mortem in assessment of meat with lowered drip loss. Samples of 100 longissimus dorsi (LD) (Landrace × Yorkshire) × Duroc fatteners were examined after slaughter for following parameters: muscle acidity in 35 min, 2 h, 3 h, 24 h and 48 h (pH1, pH2, pH3, pH24 and pH48), colour lightness (L*, a*, b*), meat yield after curing and thermal processing in 72 °C (technological yield), water-holding capacity (WHC) and drip loss in 48, 96 and 144 h (DL48, DL96, DL144). To verify the accuracy of analysed methods two groups were distinguished according to DL48, e.g. Low DL (DL48≤4%) and High DL (DL48>4%). In High DL pH1 to pH48 were statistically lower while L*, WHC, DL48, DL96, DL144 were statistically higher (P≤0.05). On the basis of pH-dependent methods classification to RFN (red, firm, normal), PSE (pale, soft, exudative), DFD (dark, firm, dry) and AM (acid meat) was performed and then the percentage share of Low DL and High DL among meat classified as RFN was evaluated. Despite most samples were classified as RFN Low DL share among them did not exceed 50%. If meat sample shows metabolites concentration below threshold value and was assigned to Low DL (or was assigned to High DL above threshold value) it was regarded as correctly classified. The most promising cut-off point (correct classification of 73%) was 45 µmol both for glycogen and lactate.

RESUMO: Neste estudo foram analisadas 100 amostras de longissimus dorsi (LD) de suinos Landrace, Yorkshire (L × Y) × Duroc (D). Dois grupos foram distinguidos de acordo com a perda por gotejamento medida 48 horas após o abate, por ex. DL baixo (DL48≤%) e DL alto (DL48> 4%). Em DL alto maior leveza (L*), capacidade de retenção de água (WHC), perda por gotejamento em 48 (DL48), 96 (DL96), 144 (DL144) e menor acidez muscular de 35 min. a 48 horas post mortem (pH1 a pH48) foram anotados (P≤0.01). A baixa participação de DL dentro das amostras classificadas como RFN (vermelha, firme, normal) com base em vários métodos de avaliação da qualidade da carne suína usando diferentes pontos de tempo de pH e valores de limiar não excederam 50%. A tentativa de uso de várias concentrações de metabólitos musculares mediu 45 min. post mortem (glicogênio, lactato e suas combinações) como valores limiares na avaliação de DL baixo e DL alto foi então realizado. Os pontos de corte mais promissores (45 µmol por g de tecido muscular tanto para glicogênio quanto para lactato) permitiram classificar corretamente 83.82% de DL baixo e 50% de DL alto respectivamente abaixo e acima deles.

Classification accuracy of different pork quality evaluation methods in assessment of meat with lowered drip loss / Precisão da classificação de métodos de avaliação da qualidade da carne suína para menor perda durante o gotejamento

This study compared the diagnostic value of pork quality evaluation methods using different pH threshold values and time-points with muscle metabolites concentration threshold values measured 45 min. post mortem in assessment of meat with lowered drip loss. Samples of 100 longissimus dorsi (LD) (Landrace × Yorkshire) × Duroc fatteners were examined after slaughter for following parameters: muscle acidity in 35 min, 2 h, 3 h, 24 h and 48 h (pH1, pH2, pH3, pH24 and pH48), colour lightness (L*, a*, b*), meat yield after curing and thermal processing in 72 °C (technological yield), water-holding capacity (WHC) and drip loss in 48, 96 and 144 h (DL48, DL96, DL144). To verify the accuracy of analysed methods two groups were distinguished according to DL48, e.g. Low DL (DL48≤4%) and High DL (DL48>4%). In High DL pH1 to pH48 were statistically lower while L*, WHC, DL48, DL96, DL144 were statistically higher (P≤0.05). On the basis of pH-dependent methods classification to RFN (red, firm, normal), PSE (pale, soft, exudative), DFD (dark, firm, dry) and AM (acid meat) was performed and then the percentage share of Low DL and High DL among meat classified as RFN was evaluated. Despite most samples were classified as RFN Low DL share among them did not exceed 50%. If meat sample shows metabolites concentration below threshold value and was assigned to Low DL (or was assigned to High DL above threshold value) it was regarded as correctly classified. The most promising cut-off point (correct classification of 73%) was 45 µmol both for glycogen and lactate.

Neste estudo foram analisadas 100 amostras de longissimus dorsi (LD) de suinos Landrace, Yorkshire (L × Y) × Duroc (D). Dois grupos foram distinguidos de acordo com a perda por gotejamento medida 48 horas após o abate, por ex. DL baixo (DL48≤%) e DL alto (DL48> 4%). Em DL alto maior leveza (L*), capacidade de retenção de água (WHC), perda por gotejamento em 48 (DL48), 96 (DL96), 144 (DL144) e menor acidez muscular de 35 min. a 48 horas post mortem (pH1 a pH48) foram anotados (P≤0.01). A baixa participação de DL dentro das amostras classificadas como RFN (vermelha, firme, normal) com base em vários métodos de avaliação da qualidade da carne suína usando diferentes pontos de tempo de pH e valores de limiar não excederam 50%. A tentativa de uso de várias concentrações de metabólitos musculares mediu 45 min. post mortem (glicogênio, lactato e suas combinações) como valores limiares na avaliação de DL baixo e DL alto foi então realizado. Os pontos de corte mais promissores (45 µmol por g de tecido muscular tanto para glicogênio quanto para lactato) permitiram classificar corretamente 83.82% de DL baixo e 50% de DL alto respectivamente abaixo e acima deles.

El cromo-levadura y la ractopamina afectan el perfil de ácidos grasos y la calidad de la carne en cerdos / Chromium-yeast and ractopamine affect the profile of fatty acids and quality of meat in pigs

RESUMEN Los consumidores de cerdo demandan productos bajos en grasa y sin aditivos que afecten la salud humana. El objetivo de este trabajo fue evaluar el efecto del cromo-levadura o ractopamina adicionadas a la dieta de cerdos, sobre el rendimiento, las características de la canal y la calidad de la carne. Se distribuyeron 20 cerdos de manera aleatoria en cuatro tratamientos: sin adición de cromo-levadura, ni ractopamina (T1); 10ppm de ractopamina (T2); 0,2ppm de cromo-levadura (T3) y 0,4ppm de cromo- levadura (T4). Se determinó el espesor de la grasa dorsal al inicio, al intermedio y al final del estudio. El rendimiento en canal caliente y fría se estimó en el frigorífico. Muestras de la cabeza del lomo fueron tomadas para evaluar pH, resistencia al corte, goteo, temperatura, retención de agua y contenido de ácidos grasos. Se realizó un análisis descriptivo de los datos y de Kruskal-Wallis, para determinar el efecto del tratamiento sobre las variables medidas. Ninguna suplementación afectó la ganancia de peso, peso final, conversión alimenticia, consumo alimento, rendimiento en canal caliente, rendimiento canal fría y grasa dorsal (P>0,05). La resistencia al corte aumentó con la ractopamina, pero disminuyó con el cromo-levadura. Las pérdidas por goteo fueron significativas con 0,2ppm de cromo-levadura, pero no lo fueron con 0,4ppm de cromo-levadura o ractopamina. No se encontró efecto de la ractopamina sobre los ácidos grasos, pero sí del cromo-levadura. Tanto el cromo-levadura como la ractopamina modifican características de la carne, como la dureza y el perfil de ácidos grasos.

ABSTRACT The consumers of pork demand products low in fat and free of additives that affect the human health. The objective of this study was to evaluate the effect of chromium-yeast or ractopamine added to the diet of pigs on the performance, characteristics of the carcass and meat quality. Twenty pigs were randomized to four treatments: without the addition of chromium-yeast or ractopamine (T1); 10ppm of ractopamine (T2); 0.2ppm of chromium-yeast (T3) and 0.4ppm of chromium-yeast (T4). The backfat thickness was evaluated at the beginning, at the intermediate and at the end of the experiment. Hot carcass yield and cold carcass yield was evaluated in the slaughter house. Loin samples were taken to evaluate pH, shear force, drip loss, temperature, water retention and fatty acid composition. A descriptive analysis of the data and Kruskal-Wallis was carried out to determine the effect of the treatment on the measured variables. Any supplementation affected significantly weight gain, final weight, feed conversion, feed intake, hot carcass yield, cold carcass yield and backfat thinkness (P>0,05). Shear force increased with ractopamine, but decreased with chrome-yeast. Drip losses were significant at 0.2ppm chromium-yeast, but were not significant at 0.4ppm chromium-yeast or ractopamine. There was no effect of ractopamine on fatty acids, but with chromium-yeast was significant. Both chrome-yeast and ractopamine modify meat characteristics such as hardness and fatty acid profile.

Brown rice, selenium yeast and alpha-tocopherol acetate in chickens diet: effects on meat quality / Arroz integral, seleno-levedura e acetato de alfa-tocoferol na dieta de frangos de corte: efeitos sobre a qualidade da carne

The effects of diet supplementation with ?-tocopherol acetate (VE) and selenium yeast (SeL) on the water holding capacity (WHC), cooking weight loss (CL), drip loss (DL), pH, colour and selenium concentration of the breast of chickens fed diets based on corn or brown rice were studied. From 21 days of age, a total of 200 birds were housed in 38 floor pens (experimental unit) in a randomised 23 factorial arrangement. The levels of supplementation were VE (0 and 200 mg/kg), organic selenium (0 and 0.3 ppm) and two diets (100% corn and 100% brown rice) in a total of eight treatments: T1) corn + 0 SeL + 0 VE (control); T2) corn + 200 mg/kg VE + 0 SeL; T3) corn + 0 VE + 0.3 ppm SeL; T4) corn + 200 mg/kg VE + 0.3 ppm SeL; T5) brown rice + 0 VE +0 SeL; T6) brown rice + 200 mg/kg VE + 0 SeL; T7) brown rice + 0 VE + 0.3 ppm SeL; T8) brown rice + 200 mg/kg VE + 0.3 ppm SeL. The concentration of selenium in the breast increased with VE supplementation in the diet (P 0.001). However, a positive interaction between VE and SeL on selenium concentration in the meat was found (P = 0.06). A better WHC with the inclusion of SeL and VE was found only in the rice-based diets. The replacement of corn by brown rice decreased (P 0.05) the yellowness of the meat. CL and DL were not significantly affected by the treatments. Broilers fed with SeL supplemented diets showed a higher pH in the breast than diets without supplementation. In conclusion, the interaction between VE and SeL increased selenium in meat but improved WHC only in rice-based diets. The replacement of corn by brown rice decreased the yellowness of chicken breast meat.(AU)

Foram estudados os efeitos da suplementação com acetato de alfa-tocoferol (VE) e seleno-levedura (SeL) Sel-Plex, Alltech® Inc, sobre o pH, a capacidade de retenção de água (CRA), perdas por cocção (PC), perdas por gotejamento (PG), cor do músculo e a concentração de selênio no peito de frangos alimentados com dietas a base de milho ou arroz. A partir de 21 dias de idade 200 frangos de corte Cobb foram alojados em 38 boxes (unidade experimental) num delineamento casualizado num arranjo fatorial 2x2x2 em que foram fixados os níveis de suplementação on top de VE (0 e 200 mg/kg), SeL (0 e 0,3 ppm) e dois ingredientes da dieta (100% milho e 100% arroz integral) totalizando oito tratamentos: T1) milho + 0SeL + 0VE (controle); T2) milho + 200mg/kg VE + 0SeL; T3) milho + 0VE + 0,3ppm SeL; T4) milho + 200mg/kg VE + 0,3ppm SeL; T5) arroz + 0VE +0SeL; T6) arroz + 200mg/kg VE + 0SeL; T7) arroz + 0VE + 0,3ppm SeL; T8) arroz + 200mg/kg VE + 0,3ppm SeL. A quantidade de selênio no peito foi maior (P 0,0001) com a inclusão de 200mg/kg de VE, em comparação com os demais tratamentos. Entretanto, observou-se uma interação positiva entre VE e SeL na dieta sobre a quantidade de selênio recuperada na carne (P = 0,06). Foi encontrada melhor CRA com a inclusão de SeL e VE em dietas a base de arroz. A substituição do milho por arroz nas dietas reduziu a cor amarela na carne (P 0,05). PC e PG não foram significativamente afetadas pelos tratamentos. O pH da carne do peito foi significativamente mais elevado nas aves recebendo dietas suplementadas de SeL. Em conclusão,a interação entre VE e SeL aumenta o selênio na carne, porém, melhorando a CRA somente em dietas a base de arroz. A substituição de milho por arroz integral reduz a intensidade da coloração amarela da carne do peito de frangos.(AU)

Brown rice, selenium yeast and alpha-tocopherol acetate in chickens diet: effects on meat quality / Arroz integral, seleno-levedura e acetato de alfa-tocoferol na dieta de frangos de corte: efeitos sobre a qualidade da carne

The effects of diet supplementation with ?-tocopherol acetate (VE) and selenium yeast (SeL) on the water holding capacity (WHC), cooking weight loss (CL), drip loss (DL), pH, colour and selenium concentration of the breast of chickens fed diets based on corn or brown rice were studied. From 21 days of age, a total of 200 birds were housed in 38 floor pens (experimental unit) in a randomised 23 factorial arrangement. The levels of supplementation were VE (0 and 200 mg/kg), organic selenium (0 and 0.3 ppm) and two diets (100% corn and 100% brown rice) in a total of eight treatments: T1) corn + 0 SeL + 0 VE (control); T2) corn + 200 mg/kg VE + 0 SeL; T3) corn + 0 VE + 0.3 ppm SeL; T4) corn + 200 mg/kg VE + 0.3 ppm SeL; T5) brown rice + 0 VE +0 SeL; T6) brown rice + 200 mg/kg VE + 0 SeL; T7) brown rice + 0 VE + 0.3 ppm SeL; T8) brown rice + 200 mg/kg VE + 0.3 ppm SeL. The concentration of selenium in the breast increased with VE supplementation in the diet (P 0.001). However, a positive interaction between VE and SeL on selenium concentration in the meat was found (P = 0.06). A better WHC with the inclusion of SeL and VE was found only in the rice-based diets. The replacement of corn by brown rice decreased (P 0.05) the yellowness of the meat. CL and DL were not significantly affected by the treatments. Broilers fed with SeL supplemented diets showed a higher pH in the breast than diets without supplementation. In conclusion, the interaction between VE and SeL increased selenium in meat but improved WHC only in rice-based diets. The replacement of corn by brown rice decreased the yellowness of chicken breast meat.

Foram estudados os efeitos da suplementação com acetato de alfa-tocoferol (VE) e seleno-levedura (SeL) Sel-Plex, Alltech® Inc, sobre o pH, a capacidade de retenção de água (CRA), perdas por cocção (PC), perdas por gotejamento (PG), cor do músculo e a concentração de selênio no peito de frangos alimentados com dietas a base de milho ou arroz. A partir de 21 dias de idade 200 frangos de corte Cobb foram alojados em 38 boxes (unidade experimental) num delineamento casualizado num arranjo fatorial 2x2x2 em que foram fixados os níveis de suplementação on top de VE (0 e 200 mg/kg), SeL (0 e 0,3 ppm) e dois ingredientes da dieta (100% milho e 100% arroz integral) totalizando oito tratamentos: T1) milho + 0SeL + 0VE (controle); T2) milho + 200mg/kg VE + 0SeL; T3) milho + 0VE + 0,3ppm SeL; T4) milho + 200mg/kg VE + 0,3ppm SeL; T5) arroz + 0VE +0SeL; T6) arroz + 200mg/kg VE + 0SeL; T7) arroz + 0VE + 0,3ppm SeL; T8) arroz + 200mg/kg VE + 0,3ppm SeL. A quantidade de selênio no peito foi maior (P 0,0001) com a inclusão de 200mg/kg de VE, em comparação com os demais tratamentos. Entretanto, observou-se uma interação positiva entre VE e SeL na dieta sobre a quantidade de selênio recuperada na carne (P = 0,06). Foi encontrada melhor CRA com a inclusão de SeL e VE em dietas a base de arroz. A substituição do milho por arroz nas dietas reduziu a cor amarela na carne (P 0,05). PC e PG não foram significativamente afetadas pelos tratamentos. O pH da carne do peito foi significativamente mais elevado nas aves recebendo dietas suplementadas de SeL. Em conclusão,a interação entre VE e SeL aumenta o selênio na carne, porém, melhorando a CRA somente em dietas a base de arroz. A substituição de milho por arroz integral reduz a intensidade da coloração amarela da carne do peito de frangos.

Effec t of Freeze-Thaw Cycles on Lipid Oxidation and Myowater in Broiler Chickens

The present study was carried out to investigate the influence of freezing-thawing cycles (0, 2, 4 and 6) on lipid oxidation and myowater contents and distribution. Nine replicates of chicken breast meat samples were used for each cycle. Lipid oxidation was determined by measuring peroxide value, and malondialdehyde (MDA) concentrations, which reflect thiobarbituric acid reactive substance (TBARS). Color was determined with a digital colorimeter. Muscle moisture contents were determined by drip loss and thawing loss, water holding capacity, and nuclear magnetic resonance (NMR). The results showed that, as the number of freeze-thaw cycles increased, meat redness decreased and MDA and peroxide values increased. Drip loss and thawing loss tended to decreasing as the number of freeze-thaw cycles increased. Water holding capacity also decreased as a function of increasing freeze-thaw cycles. NMR relaxometry profile showed freeze-thaw cycles change the water distribution of meat subjected to multiple freeze-thaw cycles. In conclusion, multiple freezing and thawing rate (6 cycles) increased lipid oxidation, decreased myowater, and impaired the color of chicken meat.(AU)

Effec t of Freeze-Thaw Cycles on Lipid Oxidation and Myowater in Broiler Chickens

The present study was carried out to investigate the influence of freezing-thawing cycles (0, 2, 4 and 6) on lipid oxidation and myowater contents and distribution. Nine replicates of chicken breast meat samples were used for each cycle. Lipid oxidation was determined by measuring peroxide value, and malondialdehyde (MDA) concentrations, which reflect thiobarbituric acid reactive substance (TBARS). Color was determined with a digital colorimeter. Muscle moisture contents were determined by drip loss and thawing loss, water holding capacity, and nuclear magnetic resonance (NMR). The results showed that, as the number of freeze-thaw cycles increased, meat redness decreased and MDA and peroxide values increased. Drip loss and thawing loss tended to decreasing as the number of freeze-thaw cycles increased. Water holding capacity also decreased as a function of increasing freeze-thaw cycles. NMR relaxometry profile showed freeze-thaw cycles change the water distribution of meat subjected to multiple freeze-thaw cycles. In conclusion, multiple freezing and thawing rate (6 cycles) increased lipid oxidation, decreased myowater, and impaired the color of chicken meat.

Broiler chicken PSE (Pale, Soft, Exudative) meat and water release during chicken carcass thawing and brazilian legislation

The objective of this work was to investigate the relationship between poultry PSE meat and water loss of frozen chicken carcass in two experiments. The first experiment was carried out in commercial abattoir. Poultry carcass were classified as PSE meat (n=59) (pH <5.8) and control samples (n=55) (pH >5.8). Water absorption and drip test were performed according to the Brazilian legislation methodologies. The second experiment was carried out with commercial whole five brands frozen carcasses purchased from the local supermarkets (n=30) and analyzed for pH, water holding capacity (WHC) and drip test. PSE poultry meats absorbed 3.59% of water during the processing similar to the control samples; however, released 0.38% more water during thawing of the carcasses. From these five brands evaluated, three presented drip values above 6.0%. The highest drip value was showed by the brand sample that had pH and WHC values characteristics of PSE meat. It could be postulated that PSE meat phenomenon promoted more water release during thawing leading to a misinterpretation in relation to the Brazilian legislation for water carcass liberation during thawing.

Efeito da automatização nas diferentes estações do ano sobre os parâmetros de desempenho, rendimento e qualidade da carne de frangos de corte / Effect of handling system and seasons of the year on performance carcass yield and meat quality of broiler chicken

O experimento teve por objetivo avaliar o efeito do sistema de criação e da época do ano, sobre o desempenho e qualidade da carne de frangos de corte. Foram estudadas 524.000 aves da linhagem comercial Cobb 500, distribuídas em três galpões com diferentes sistemas de automatização, durante as quatro estações do ano. O delineamento foi inteiramente casualizado, com esquema fatorial 3 x 4 (tipo de galpão x época do ano). Foram utilizadas rações do sistema integrado, cama de palha de arroz, e as aves foram abatidas em um frigorífico aos 43 dias de idade. Foram avaliados os dados de desempenho (consumo de ração, ganho de peso diário, conversão alimentar e mortalidade), com dados fornecidos pelo sistema integrado. Também, foram avaliados os defeitos nas carcaças, e análises de pH, maciez e perda de água da carne. As aves criadas nos sistemas automatizado e semiautomatizado, e nos períodos mais quentes do ano, apresentaram menor rendimento de carcaça e piores características de qualidade de carne (maior perda de peso, menor maciez e maior acidez), e maior incidência de defeitos nas carcaças. As aves criadas no sistema não-automatizado e nos períodos mais frios apresentaram melhor desempenho, com menor índice de mortalidade e melhor qualidade da carne.(AU)

This study had as objective to evaluate the effect of the handling system and season of the year on the performance and meat quality of broiler chicken. Five hundred twenty-four thousand commercial Cobb 500 chicks were allocated in three different handling systems, during the four seasons of the year. The experimental design was completely randomized, with a 3 x 4 factorial scheme (three types of storage shed and four seasons). The diet was provided by a co-operative system and consisted of rice straw, and the broilers were slaughtered in a slaughterhouse at 43 days of age. Feed intake, weight, daily weight gain and mortality rate were available with data provided by the co-operative system. Carcass defects were also evaluated, and analyses of pH, tenderness and drip loss of meat were determined. The chickens raised in automatic and semi-automatic systems and during warm seasons showed lower carcass yield and worse meat quality (great values of drip loss and acidity, small values of tenderness), and higher rates of carcass defects. Chickens raised in a non-automatic system and during cold seasons showed the best performance, with low mortality rate and the best meat quality.(AU)

Efeito da automatização nas diferentes estações do ano sobre os parâmetros de desempenho, rendimento e qualidade da carne de frangos de corte / Effect of handling system and seasons of the year on performance carcass yield and meat quality of broiler chicken

O experimento teve por objetivo avaliar o efeito do sistema de criação e da época do ano, sobre o desempenho e qualidade da carne de frangos de corte. Foram estudadas 524.000 aves da linhagem comercial Cobb 500, distribuídas em três galpões com diferentes sistemas de automatização, durante as quatro estações do ano. O delineamento foi inteiramente casualizado, com esquema fatorial 3 x 4 (tipo de galpão x época do ano). Foram utilizadas rações do sistema integrado, cama de palha de arroz, e as aves foram abatidas em um frigorífico aos 43 dias de idade. Foram avaliados os dados de desempenho (consumo de ração, ganho de peso diário, conversão alimentar e mortalidade), com dados fornecidos pelo sistema integrado. Também, foram avaliados os defeitos nas carcaças, e análises de pH, maciez e perda de água da carne. As aves criadas nos sistemas automatizado e semiautomatizado, e nos períodos mais quentes do ano, apresentaram menor rendimento de carcaça e piores características de qualidade de carne (maior perda de peso, menor maciez e maior acidez), e maior incidência de defeitos nas carcaças. As aves criadas no sistema não-automatizado e nos períodos mais frios apresentaram melhor desempenho, com menor índice de mortalidade e melhor qualidade da carne.

This study had as objective to evaluate the effect of the handling system and season of the year on the performance and meat quality of broiler chicken. Five hundred twenty-four thousand commercial Cobb 500 chicks were allocated in three different handling systems, during the four seasons of the year. The experimental design was completely randomized, with a 3 x 4 factorial scheme (three types of storage shed and four seasons). The diet was provided by a co-operative system and consisted of rice straw, and the broilers were slaughtered in a slaughterhouse at 43 days of age. Feed intake, weight, daily weight gain and mortality rate were available with data provided by the co-operative system. Carcass defects were also evaluated, and analyses of pH, tenderness and drip loss of meat were determined. The chickens raised in automatic and semi-automatic systems and during warm seasons showed lower carcass yield and worse meat quality (great values of drip loss and acidity, small values of tenderness), and higher rates of carcass defects. Chickens raised in a non-automatic system and during cold seasons showed the best performance, with low mortality rate and the best meat quality.

Quality of wild boar meat and commercial pork

Presently there is a growing interest in the production and marketing of wild boar meat, and to attend a differentiated consumer demand the quality attributes of this product should be well established. To characterize the quality of wild boar meat in comparison to commercial pork, post mortem changes in the longissimus dorsi and semimembranosus muscles were determined by pH and temperature decline, and color (CIE L*a*b*) measurements. Water holding capacity (WHC) was determined by the compression method and the exudate loss (EL) by the drip loss test. Decline in longissimus dorsi muscle pH of wild boar was gradual and in the pork it was faster and more extensive. Temperature differences were observed in some post mortem times, and the lowest values were found in wild boar carcasses. Wild boar meat presented lower values of L* (brightness) and b* (yellow color intensity), and higher values of a* (red color intensity) than pork. The WHC of the wild boar meat was similar to pork, but the EL in female wild boar meat was lower than in pork.

Atualmente existe no Brasil um interesse crescente na criação e exploração comercial da carne de javali e para atender a uma demanda diferenciada é importante que os atributos qualitativos do produto sejam bem estabelecidos. Com o objetivo de caracterizar a carne de javali nos parâmetros de qualidade e compará-la com a carne suína comercial, as mudanças nos músculos Longissimus dorsi e Semimembranosus, no post mortem, foram acompanhadas com medidas de pH, temperatura e cor (CIE L*a*b*). A capacidade de retenção de água (CRA) foi determinada pelo método de compressão e a perda de exsudato (PE) pelo teste de "drip loss". A queda de pH na carne de javali ocorreu de forma gradual, enquanto que no Longissimus dorsi de suíno a diminuição foi mais rápida e mais extensa. Diferenças de temperatura foram verificadas em alguns tempos post mortem, sendo que os menores valores foram encontrados nos javalis. A carne de javali teve valores menores de L* (luminosidade) e b* (intensidade de amarelo) e maiores de a* (intensidade de vermelho) que a carne suína. A CRA da carne dos javalis foi semelhante à da carne suína, mas a PE na carne de javali fêmea foi menor do que na de suíno.

Quality of wild boar meat and commercial pork

Presently there is a growing interest in the production and marketing of wild boar meat, and to attend a differentiated consumer demand the quality attributes of this product should be well established. To characterize the quality of wild boar meat in comparison to commercial pork, post mortem changes in the longissimus dorsi and semimembranosus muscles were determined by pH and temperature decline, and color (CIE L*a*b*) measurements. Water holding capacity (WHC) was determined by the compression method and the exudate loss (EL) by the drip loss test. Decline in longissimus dorsi muscle pH of wild boar was gradual and in the pork it was faster and more extensive. Temperature differences were observed in some post mortem times, and the lowest values were found in wild boar carcasses. Wild boar meat presented lower values of L* (brightness) and b* (yellow color intensity), and higher values of a* (red color intensity) than pork. The WHC of the wild boar meat was similar to pork, but the EL in female wild boar meat was lower than in pork.

Atualmente existe no Brasil um interesse crescente na criação e exploração comercial da carne de javali e para atender a uma demanda diferenciada é importante que os atributos qualitativos do produto sejam bem estabelecidos. Com o objetivo de caracterizar a carne de javali nos parâmetros de qualidade e compará-la com a carne suína comercial, as mudanças nos músculos Longissimus dorsi e Semimembranosus, no post mortem, foram acompanhadas com medidas de pH, temperatura e cor (CIE L*a*b*). A capacidade de retenção de água (CRA) foi determinada pelo método de compressão e a perda de exsudato (PE) pelo teste de "drip loss". A queda de pH na carne de javali ocorreu de forma gradual, enquanto que no Longissimus dorsi de suíno a diminuição foi mais rápida e mais extensa. Diferenças de temperatura foram verificadas em alguns tempos post mortem, sendo que os menores valores foram encontrados nos javalis. A carne de javali teve valores menores de L* (luminosidade) e b* (intensidade de amarelo) e maiores de a* (intensidade de vermelho) que a carne suína. A CRA da carne dos javalis foi semelhante à da carne suína, mas a PE na carne de javali fêmea foi menor do que na de suíno.