Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective was to assess the technical feasibility of finishing lambs fed exclusively concentrate in feedlot or on pasture and the effect of these diets on carcass characteristics, meat quality and implications in terms of the welfare of animals. Lambs, crosses Texel and Ile de France were used. The diet of the confined animals consisted of 77.4% of corn grain; 20.2% of soybean meal; 1.4% of limestone, and 1.0% of sodium bicarbonate. In the pasture finishing system, natural pasture + annual ryegrass were used. Regarding the technical feasibility, the feedlot system was superior, showed greater weight gain, better conversion rates and feeding efficiency, fewer days to reach slaughter weight and better carcass characteristics. The amount of sodium bicarbonate used in the feedlot diet was not sufficient to regulate ruminal pH. Regarding the quality of the meat, the feeding system did not influence the carcass final pH, losses for defrosting and cooking elasticity and meat color. The meat produced in feedlot was more tender. Regarding types of meat characteristics that relate to consumer health, the lamb meat produced on pasture was superior, since it had 40.8% less fat, higher protein content, lower cholesterol content, higher percentage of fatty acids of long and very long chain, n-3 fatty acids, best n6: n3 ratio and best atherogenicity and thrombogenicity rates. As for the behavior, the animals finished in feedlot reduced rumination time, increased stereotyped behavior and showed depraved appetite; when assessed in relation to physiological parameters after 51 days fed exclusive concentrate, animals in feedlot had higher levels of serum cortisol in relation to animals rearing on the natural pasture. The pasture finishing system has a higher percentage of compliance in relation to world protocols of animal walfare and five freedom theory. The feeding systems used have technical feasibility for finishing lambs in different seasons and influence carcass characteristics, meat quality and related to animal welfare, resulting in meat and carcass with different characteristics. / Objetivou-se avaliar a viabilidade técnica da terminação de cordeiros em confinamento com dieta exclusiva de concentrado ou a pasto e o efeito destas dietas nas características da carcaça, qualidade da carne e implicações nas condições de bem-estar dos animais. Foram utilizados cordeiros cruza Texel e Ile de France. A dieta dos animais confinados foi constituída de 77,4% de grão de milho; 20,2% de farelo de soja; 1,4% de calcário calcítico e 1,0% de bicarbonato de sódio. No sistema a pasto, foi utilizada pastagem natural na recria e azevém (Lolium multiflorum Lam.) na terminação. Em relação à viabilidade técnica, o sistema de confinamento foi superior, apresentou maior ganho médio diário, melhores valores de conversão e eficiência alimentar, número menor de dias para chegar ao peso de abate e melhores características de carcaça. A quantidade de bicarbonato de sódio utilizada na dieta do confinamento, não foi suficiente para regular o pH ruminal. Em relação à qualidade da carne, o sistema de alimentação não influenciou o pH final da carcaça, as perdas por descongelamento e cocção, a elasticidade e a cor da carne. A carne produzida em confinamento foi mais macia. Em relação ás características da carne que se relacionam com a saúde do consumidor, a carne ovina produzida a pasto foi superior, uma vez que apresentou 40,8% menos gordura, maior teor de proteína, menor teor de colesterol, maior percentual de ácidos graxos de cadeia longa e muito longa, de ácidos graxos n-3, melhor relação n6:n3 e melhores índices de aterogenicidade e trombogenicidade. Em relação ao comportamento, os animais terminados em confinamento reduziram o tempo de ruminação, aumentaram comportamento estereotipado e apresentaram apetite depravado. Quando avaliados em relação aos parâmetros fisiológicos, após 51 dias de dieta exclusiva de concentrado, os animais do confinamento apresentaram níveis superiores de cortisol sérico em relação aos animais em recria na pastagem natural. O sistema de terminação a pasto apresenta maior percentual de conformidades em relação aos protocolos mundias de bem-estar animal e teoria das cinco liberdades. Os sistemas de alimentação utilizados apresentam viabilidade técnica para terminação de cordeiros em diferentes épocas do ano e influenciam caracteristicas de carcaça, de qualidade da carne e relacionadas ao bem-estar dos animais, originando carnes e carcaças com características diferentes.

Plusieurs acteurs moléculaires impliqués dans les variations de qualité de la viande ont été récemment mis en évidence chez le poulet. Ma thèse a pour objectif d’approfondir l’étude de leur régulation en étudiant l’impact de facteurs alimentaires en interaction avec l’origine génétique des animaux. Il s’est articulé autour de deux thématiques qui impliquent des acteurs moléculaires et des critères de qualité de viande indépendants : le rôle de l’AMPK (AMP-activated protein kinase) dans le contrôle du turnover du glycogène musculaire et des caractères qui en dépendent (pH, rétention d’eau, couleur) et l’implication de BCMO1 (β, β-carotene-15,15’-monooxygenase) dans les variations de teneurs en pigments caroténoïdes et de coloration. Nos résultats soulignent dans les deux cas la possibilité de moduler les caractères de qualité via l’alimentation avec des réponses qui dépendent des caractéristiques génétiques des animaux. Nos travaux ont aussi permis d’améliorer la compréhension de la régulation des biomarqueurs étudiés par les nutriments et la génétique et contribueront à terme à la mise en place de nouvelles stratégies de production permettant d’optimiser la qualité du poulet de chair en réponse aux attentes de la filière et des consommateurs. / Several molecular mechanisms involved in the variations of poultry meat quality were recently identified in chickens. My thesis aims to further study their regulation by exploring the impact of dietary factors in interaction with the genetic origin of animals. It was structured around two themes that involve independent molecular mechanisms and meat quality criteria: the role of AMPK (AMP-activated protein kinase) in the control of muscle glycogen turnover and related meat traits (pH, water retention, color), and the involvement of BCMO1 (β, β-carotene-15, 15'-monooxygenase) in controlling levels of carotenoid pigments and yellow color. Our results emphasize in both cases the possibility of modulating quality traits through nutrition, with effects that depend on the genetic characteristics of animals. Our work has also improved the understanding of the regulation of studied biomarkers by genetics and nutrients. This should contribute to the development of new production strategies to optimize the quality of broilers in response to expectations of poultry producers and consumers.

This study was aimed on analysis of polymorphism at position 2141 in exon 5 of the growth hormone gene (GH) and polymorphism at position 257 in exon 10 of the growth hormone receptor gene (GHR) and to determine the influence of these polymorphisms on meat tenderness. To analysis has been used 333 meat samples of Czech Pied bulls. Genotypization of GH and GHR loci was performed by PCR-RFLP. For detection of single nucleotide polymorphism in both genes was used restriction endonuclease AluI. To determine meat tenderness was used the method of measuring shear force by Warner and Bratzler. The shear force values of raw meat samples were measured at day 14 post mortem. Then was statistically evaluated the association between genotypes and shear force. In the study population occurred for GH locus 166 individuals with genotype LL, 161 heterozygotes LV and 6 homozygotes VV. The relative genotype frequencies were thus 0.499 (LL), 0.483 (LV) and 0.018 (VV). The frequency of L allele was 0,74 and of V allele was 0,26. For GHR locus was found in the study population 178 homozygotes AA, 105 heterozygotes AG and 50 homozygotes GG. The relative frequencies of genotypes were 0.535 (AA), 0.315 (AG) and 0.15 (GG). The frequency of A allele was 0,692 and of G allele was 0,308. Using statistical analysis revealed a significant effect of genotype GH gene on shear force, tenderness resp. (P<0,05). For GHR locus showed no effect of genotype on shear force (P>0,05).

Made available in DSpace on 2015-03-26T13:55:25Z (GMT). No. of bitstreams: 1 texto completo.pdf: 778375 bytes, checksum: 97156e3e6f5b7ceee5985d54b84d365c (MD5) Previous issue date: 2014-07-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / To evaluate the effect of chromium yeast (CY) and ractopamine (RAC) on performance, carcass characteristics, meat quality, and blood, an experiment was conducted with 96 commercial castrated crossbred pigs with an average initial body weight of 75.07 ± 3.9 kg. Animals were distributed in a randomized-block experimental design with six treatments, eight blocks and two animals per stall. The treatments consisted of feeding plans (FP) in two phases: from 0 to 14 days; and from 14 to 42 days of age, respectively, composed of diets: Control/Control (CD/CD); Chromium yeast/Amino acids (CY/AA); Chromium yeast/Amino acids + Ractopamine (CY/AA+RAC); Control /Chromium yeast (CD/CY); Control/Amino acids + Chromium Yeast (CD/AA+CY); and Chromium Yeast/Amino Acids + Ractopamine + Chromium Yeast (CY/AA+RAC/CY). The greatest final weight and daily weight gain (P<0.0001) were observed in the animals subjected to CY/AA+RAC+CY. Feeding plan CY/AA+RAC provided an intermediate final weight and daily weight gain, similar to those obtained with the use of CY/AA+RAC+CY, CD/CD, CY/AA and CD/CY, but greater than CD/AA+CY. The pigs fed CY/AA+RAC+CY showed a greater fasted body weight (FW) (P<0.0001) as compared with CD/CD, CY/AA, CD/CY and CD/AA+CY. Feeding plan CY/AA+RAC provided an intermediate FW, similar to that obtained with the use of CY/AA+RAC+CY, CD/CD, CY/AA, but greater than CD/AA+CY. The evaluated FP did not influence (P>0.05) daily feed intake. The best feed-conversion results (P<0.0001) were obtained with CY/AA+RAC+CY and CY/AA+RAC. A larger loin-eye area was found in pigs subjected to CY/AA+RAC as compared with the use of CD/CY. The greatest muscle fiber diameter (P<0.011) was found in the pigs subjected to CY/AA+RAC+CY and CD/CY, which were higher than the group fed CD/CD. The liquid loss due to thawing determined in the meat of the pigs subjected to CD/CD was lower (P<0.009) than that observed with the use of CY/AA+RAC. A higher value of Cie a* was determined in the meat of the animals subjected to CY/AA+RAC as compared with CY/AA+ RAC+ CY. The pigs fed CY/AA+ RAC+ CY had a brighter meat than the other animals. The lowest TBARS concentration (P<.001) was observed in the meat of pigs subjected to CY/AA+RAC in relation to the group that consumed CY/AA. A greater concentration of myristic fatty acid (FA) (14:0) was found in the groups that received CY/AA+RAC as compared with the group fed CY/AA+RAC+CY. The pigs that received the FP with CY/AA+RAC+CY and CD/CY displayed greater levels of linoleic FA (18:2n6) in the longissimus dorsi muscle, as compared with the pigs fed CY/AA. The feeding plans did not affect the evaluated blood parameters (P>0.05). The use of chromium yeast and ractopamine or alone promoted positive alterations in the development of muscle cells in the pigs and in the meat quality, which should be considered when this mineral is used. The association of chromium yeast with ractopamine revealed improvements in the animal performance. / Para avaliar o efeito do cromo levedura (CrL) e ractopamina (RAC) em rações sobre o desempenho, características da carcaça, qualidade de carne e variáveis sanguíneas, foi realizado um experimento com 96 suínos machos castrados híbridos comerciais com peso corporal médio inicial de 75,07 ± 3,9 kg, distribuídos em delineamento experimental em blocos casualizados, com seis tratamentos, oito blocos e dois animais por baia. Os tratamentos foram constituídos de planos nutricionais (PN) em dois períodos consecutivos: período 1 de 0 a 14 dias e o período 2 de 14 a 42 dias, respectivamente, compostos pelas rações: Controle/Ração Controle (RC/RC); Cromo levedura/Aminoácidos (CrL/AA); Cromo Levedura/Aminoácidos + Ractopamina (CrL/AA+RAC); Controle/Cromo Levedura (RC/CrL); Ração Controle/Aminoácidos + Cromo Levedura (RC/AA+CrL) e Cromo Levedura/Aminoácidos+Ractopamina+Cromo Levedura (CrL/AA+RAC+CrL). Maior peso final (PF) e ganho de peso diário (GPD) (P<0,001) foi observado para os suínos submetidos ao PN CrL/AA+RAC+CrL. O PN CrL/AA+RAC proporcionou PF e GPD intermediário, semelhante aos obtidos com o uso de CrL/AA+RAC+CrL, RC/RC, CrL/AA e RC/CrL e superior ao PN RC/AA+CrL. Os suínos alimentados com o PN CrL/AA+RAC+CrL apresentaram maior peso de jejum (PJ) (P<0,0001) quando comparados aos PN RC/RC, CrL/AA, RC/CrL e RC/AA+CrL. O PN CrL/AA+RAC promoveu PJ intermediário, semelhante ao obtido com o uso de CrL/AA+RAC+CrL, RC/RC, CrL/AA e superior ao RC/AA+CrL. Os PN avaliados não influenciaram (P > 0,05) o consumo diário de ração. Os melhores resultados de conversão alimentar (P<0,001) foram obtidos com os PN CrL/AA+RAC+CrL e CrL/AA+RAC. Maior área de olho de lombo foi determinada nos suínos submetidos ao PN CrL/AA+RAC quando comparado a utilização de RC/CrL. Maior diâmetro da fibra muscular (P<0,011) foi verificado nos suínos submetidos aos PN CrL/AA+RAC+CrL e RC/CrL sendo estes superiores ao grupo consumindo RC/RC. A perda líquida por descongelamento determinada na carne dos suínos submetidos ao PN RC/RC foi inferior (P<0,009) a obtida com o uso do PN CrL/AA+RAC. Maior valor Cie a* foi determinado na carne dos animais submetidos ao PN CrL/AA+RAC quando comparado ao PN CrL/AA+ RAC+ CrL. Os suínos submetidos ao PN CrL/AA+ RAC+ CrL apresentaram maior tonalidade na carne frente aos demais animais. Menor concentração de TBARS (P<0,001) foi verificada na carne dos suínos submetidos ao PN CrL/AA+RAC frente ao grupo consumindo ração CrL/AA. Maior teor de ácido graxo (AG) mirístico (14:0) foi verificado para os suínos submetidos ao PN CrL/AA+RAC quando comparado ao grupo CrL/AA+RAC+CrL. Os suínos que receberam os PN com CrL/AA+RAC+CrL e RC/CrL apresentaram maior concentração de AG linolêico (18:2n6) no músculo Longissimus dorsi, frente aos suínos do PN CrL/AA. Os PN não influenciaram as variáveis sanguíneas avaliadas (P>0,05). O uso de cromo levedura e ractopamina promoveram alterações positivas sobre o desenvolvimento de células musculares nos suínos e na qualidade da carne que devem ser consideradas quando da utilização do mineral e o uso em associação a ractopamina revelou melhorias sobre o desempenho dos animais.

Made available in DSpace on 2014-07-29T15:07:48Z (GMT). No. of bitstreams: 1 dissetacao renata.pdf: 569516 bytes, checksum: 1593b15e04d7cc7d31a23f1ca9feef36 (MD5) Previous issue date: 2008-12-16 / The technology of animal origin products increase considerably, and the meat with its commercial importance is the main focus in the technologic development, searching for less costs production, major regiment and mainly better quality of the final product, however, some aspects are not totally clear, among them it finds the electrical stimulation effect and the freezing temperature influencing in the meat quality. The aim of this research was to evaluate the electrical stimulation effect and the freezing speed, about aspects that influences the meat quality. Twenty Nellore bovines non gelding bred were slaughter, around 24 months, kept in feedlot. After bleeding, half animals of each group were electrically stimulated. The carcass were submitted to one of the freezing treatment, conventional and slowly. During the freezing it were registered the curves of temperature reduction and the carcass pH reduction. After the opening of the cameras, the animals were taken to the room where the bones were taken out and then strip loin (longissimus dorsi muscle) of 2.5 cm of thickness approximately, and strip loin steaks with 1.0 cm close to. After 30 minutes it were evaluated the steak color using the portable colorímetro in the structure CIE L*, a* and b*. The steaks were vacuum packed and kept in the stock camera in 0oC for 24 hours. After this period it was analyzed for cooking loss, shear force and length sarcomere. There was (p<0.05) effect of the cooling and the electrical stimulation method in the sarcomere length measure. The sample slowly freezing without electrical stimulation showed biggest lengths sarcomere than the ones freezing by the conventional method, however, in the conventional freezing with the electrical stimulation, the samples stimulated had biggest length sarcomere than the samples of carcass no electrically stimulated. There was effect (p<0.05) of the freezing method in the shear force. The sample freezing slowly had smaller force of shear force considering the same way of freezing. There was not effect (p>0.05) of the freezing method and the electrical stimulation use in the loss cooking and in the values of luminosity L*, a*, b* in the strip loin samples. / A tecnologia aplicada aos produtos de origem animal avança acentuadamente, e a carne com sua importância comercial, é o principal foco desses avanços tecnológicos, procurando reduzir custos, aumentar rendimentos e principalmente melhor a qualidade do produto final. Entretanto alguns aspectos não estão totalmente esclarecidos, dentre eles encontra-se o efeito da estimulação elétrica e do resfriamento sobre a na qualidade da carne. O objetivo desta pesquisa foi avaliar o efeito da estimulação elétrica e da velocidade de resfriamento, sobre parâmetros qualitativos e quantitativos ( pH, perda por cozimento, força de cisalhamento, comprimento de sarcômero e cor ) de carnes. Foram utilizados 20 bovinos inteiros, com idade média de 24 meses, terminados em confinamento sendo animais da raça Nelore. Após o abate e a sangria, metade das carcaças foram estimulados eletricamente, destas cinco foram submetidas ao tratamento de resfriamento convencional e cinco ao resfriamento lento sendo o mesmo procedimento aplicada as não estimuladas. Durante o resfriamento foram registradas a redução de temperatura e redução do pH das carcaças. Após 48 horas do abate as carcaças foram desossadas e em seguida foram retirados bifes de contrafilé de 2,5 cm de espessura aproximadamente, e bifes com 1,0 cm aproximadamente. Após 30 minutos foi avaliada a cor dos bifes utilizando-se colorímetro portátil no esquema CIE L*, a* e b*. Os bifes foram embalados a vácuo e permaneceram na câmara de estocagem a 0oC por 24 horas. Após este período foram analisadas para com relação a perdas de peso por cozimento, força de cisalhamento e comprimento de sarcômero. As amostras resfriadas lentamente sem o uso da estimulação elétrica apresentaram maiores comprimento de sarcômero (p<0,05) que as amostras resfriadas pelo método convencional sem estimulação elétrica, no entanto no resfriamento convencional com o uso da estimulação elétrica, as amostras estimuladas possuíram maiores comprimentos de sarcômero (p<0,05) que as amostras das carcaças não estimuladas eletricamente. Amostras resfriadas lentamente apresentaram menores forças de cisalhamento (p<0,05) que as amostras resfriadas pelo método convencional. As amostras estimuladas eletricamente apresentaram menores forças de cisalhamento (p<0,05) que as amostras não estimuladas. Não houve efeito (p>0,05) do método de resfriamento e do uso da estimulação elétrica na perda por cozimento e nos parâmetros de cor L*, a*, b* nas amostras de contrafilé.

Made available in DSpace on 2014-08-20T13:42:10Z (GMT). No. of bitstreams: 1 Tese_Renata_Schmidt_Filgueras.pdf: 2801681 bytes, checksum: 977f5228a16ea0addcff2a8a6f4e1cd3 (MD5) Previous issue date: 2010-07-20 / Biochemical characteristics and oxidative stability during chilling and frozen were studied in M. Gastrocnemius pars interna (GN) and M. Iliofiburalis (IF) of rhea americana. The histochemical and morphometrical study was also conducted to determine fibre types and structural and ultrastructural differences between GN and IF muscles of rhea. Finally, the in vitro protein digestibility and the nutritional value of proteins were also investigated after storage/ageing and cooking in GN muscle. The ultimate pH was similar in both muscles, but the glycolytic potential (GP) was significantly higher in IF than in GN muscle. Under chilling (4 °C) and air-packaging rhea muscles exhibited differences in their stability. In particular, the IF muscle presented high colour instability and high lipid and protein oxidations after 5 days of air-packaged storage. Under chilling (4 °C) and vacuum-packaging both muscles were highly stables during 28 days and did not present evidences of oxidation. Under frozen (-20 °C) GN muscle was perfectly stable during 180 days, but IF muscle presented evidences of lipid and myoglobin oxidation after 90 days of storage. The fatty acid composition, higher lipid content and the higher myoglobin concentration in IF than in GN muscle could partially explain the instability of IF muscle during air-packaging, but the high residual glycogen observed in biochemical analysis also seemed to be involved in the occurrence of the oxidative process. The histochemical analysis of rhea limb muscles demonstrated the presence of only one type of fibres in both GN and IF muscles, i.e. fast-twitch oxidative and glycolytic (FOG) fibres. The homogeneity of fibres was evident after m-ATPase, SDH and glycogen staining reactions. In addition, the ultrastructural observation of rhea myofibrils showed contracted and stretched areas, as well as abundant glycogen and numerous mitochondria, mainly in IF muscle. Finally, the study of protein nutritional value and protein rate of digestion indicated that storage/ageing had less impact than cooking on protein oxidation and aggregation. After cooking (100 °C, 30 min) the aggregates increased 400% and the content of aromatic amino acids decreased. The nutritional value of proteins was affected by cooking, as demonstrated by the decrease of pepsin activity rate. However, trypsin chymotrypsin activities were stable after heat treatment. / As características bioquímicas e a estabilidade oxidativa durante o armazenamento foram estudadas nos músculos Gastrocnemius pars interna (GN) e Iliofiburalis (IF) de emas (rhea americana). Além disso, o estudo histoquímico e morfológico foi conduzido para determinar o tipo metabólico e contráctil das fibras musculares e as diferenças estruturais e ultra-estruturais entre os dois músculos. Por fim, a taxa de digestão e o valor nutricional das proteínas miofibrilares foram investigados após armazenamento/maturação e cocção da carne do músculo GN. O pH final de ambos os músculos foi semelhante, mas o potencial glicolítico (PG) do músculo IF foi significativamente superior ao do músculo GN. Sob refrigeração (4 °C) e embalagem permeável ao oxigênio os músculos de ema apresentaram diferenças de estabilidade oxidativa. Particularmente, o músculo IF mostrou grande instabilidade de cor e altos níveis de oxidação lipídica e protéica ao final de cinco dias de armazenamento. Sob refrigeração e embalagem a vácuo ambos os músculos foram estáveis durante 28 dias, não apresentando evidências de oxidação. Sob congelamento, enquanto o músculo GN foi estável durante 180 dias, o músculo IF mostrou indícios de oxidação de lipídios e da mioglobina a partir de 90 dias. O perfil dos ácidos graxos, a maior quantidade de lipídios totais e a maior concentração de mioglobina do músculo IF explicam parcialmente sua maior instabilidade oxidativa quando exposto ao oxigênio. Porém, a grande quantidade de glicogênio residual observada no músculo IF após análise bioquímica também parece estar envolvida na ocorrência dos processos oxidativos. A análise histoquímica dos músculos GN e IF de emas mostrou a presença de somente um tipo de fibra muscular em ambos os músculos, isto é, todas as fibras analisadas foram classificadas como fibras de metabolismo misto (oxidativo e glicolítico) e contração rápida. A homogeneidade do tipo de fibras foi evidenciada após a aplicação de técnicas histoquímicas que determinaram a atividade da m-ATPase, a atividade da succinato desidrogenase (SDH) e presença de glicogênio muscular. Além disso, a observação ultra-estrutural das miofibrilas mostrou áreas de contração e áreas de extensão, assim como abundância de mitocôndrias e de glicogênio, principalmente no músculo IF. Por fim, o estudo do valor nutricional e da taxa de digestão das proteínas miofibrilares da carne de ema indicaram que a maturação foi menos impactante do que a cocção sobre a oxidação das proteínas e formação de agregados. Após cocção (100 °C, 30 min), a quantidade de agregados aumentou até 400% na carne de ema e os teores de amino ácidos aromáticos caíram. A taxa de digestão pela pepsina diminuiu após tratamento térmico, enquanto a taxa de digestão pela tripsina/quimotripsina manteve-se estável.

The main objective of the current study was to determine the effect of distance travelled (DT), lairage duration (LDhr) and animal-related factors (animal class, breed, sex) on pre-slaughter stress indicators, carcass characteristics, nanostructure and technological properties of beef. The study was conducted in an Eastern Cape abattoir under the Buffalo City District Municipality. Six genotypes of cattle (Beefmaster, Bonsmara, Brahman, Holstein-Friesian, Non-descript and Nguni) brought for slaughter at the abattoir on different days were used in the study. Slaughter weight (SWT), warm and cold carcass weight (WCW and CCW), fatness and conformation of each animal were measured and recorded. Representative samples of blood plasma and meat quality from the Muscularis thoracis et lumborum (LTL) were collected at slaughter and 24 hours after slaughter, respectively. Heat shock proteins 70kDa (HSPA1A), glucose (GLU), cortisol (CORT), creatine kinase (CK) and lactate dehydrogenase (LDH) were determined from the blood plasma. The representative LTL muscle was used to determine ultimate pH (pHu), lightness (L*), redness (a*), yellowness (b*), meat temperature (Tm), Warner Bratzler Shear Force (WBSF) and histological structure of beef. There were significant effects of distance on pHu, Tm, a*, b*, TL%, CK and LDH. Pearson correlations were observed between distance travelled (DT), creatine kinase (CK), lactate dehydrogenase (LDH), ultimate pH (pHu), colour coordinates (L*, a* and b*) and Warner Bratzler Shear Force (WBSF). Principal component analysis (PCA) revealed that the 1st (pHu), 2nd (Tm) and 3rd (L*) principal components were the critical meat quality attributes. Positive relationships between carcass weights and beef quality characteristics for bovine cattle where the cumulative percentage of the first six principal component`s (PC`s) (SWT, WCW, CCW, DP, pHu and Tm contributed to 93.4 % of the total variance. Significant correlation coefficients between DT (r = 0.15), LDhr (r = 0.29), Ta (r = -0.52), Tm (r = 0.26), L* (r = 0.33), a* (r = 0.32) and WBSF (r = -0.49) were observed. Meat from Brahman (BR), Non-descript (ND) and Nguni (NG) cows had visible skeletal muscle fibres which were thin and long indicating improved tenderness of beef. Exposing animals to longer hours of transportation did not only reduce glucose levels but also increased the expression of HSPA1A and levels of cortisol. The CK and LDH were not related to beef quality. Therefore, CK and LDH can be used as indicators of animal welfare in slaughter cattle but cannot be used to predict the quality of meat. Bulls were the heaviest, although heifers had the highest dressing percentage than cows. Furthermore, the nanostructure of beef indicated that heifers had the best muscle fibres, sarcomere length and visible intercalated discs. The observed nanostructures of Nguni genotype are an indication of tender meat. Beef from heifers of Nguni had visible and tender meat with traces of intramuscular fat while males had shorter sarcomere length and tougher meat.

The objective of this study was to compare the nutrient status of full scavenging and semi-scavenging village chicken production systems. The semi-scavenging chickens were given broiler finisher mash between 14-24 weeks of age, whilst the full scavenging relied on natural foraging. The study also sought to compare the quality of meat from chickens from the two systems. After slaughtering the chickens, the crop contents were physically separated and analysed for chemical composition. Meat pH and colour were measured on the breast muscle of individual carcasses and a consumer sensory evaluation was also done on the breast muscle. The mean crop content weights per day were significantly higher in full scavenging chickens (±16.7g/day biomass) than in semi-scavenging chickens (±9.14g/day). Dry matter, calcium, and phosphorus levels were higher in the crop contents of the full than in the semi-scavenging chickens but crude protein, crude fibre and metabolisable energy were higher in the latter system. Semi-scavenging (1.3 ± 0.05kg) carcasses were heavier (P<0.05) than full scavenging ones (1.0 ± 0.06kg). The ultimate pH (24h) (pHu) of meat from full scavenging chickens (6.0 ± 0.03) was higher (P<0.05) than that of meat from the semi-scavenging chickens (5.7 ± 0.04). Meat from the full scavenging chickens had higher L* values (60 ± 1.2) than meat from the semi-scavenging chickens (47 ± 0.8). The a* value of meat of full scavenging chickens was significantly (P<0.05) less (4 ± 0.4) than that of meat from semi-scavenging chickens (15 ± 1.3). There was a significant positive (0.60) correlation between pHu and L* of meat from village chickens across rearing systems. The semi-scavenging system meat had better sensory attributes than the meat from the full scavenging system. Female consumers scored the typical flavour of village chicken meat across rearing systems higher (P< 0.05) than male consumers. The Shona consumers scored the meat higher (P< 0.05) than the Xhosa, Zulu, Ndebele and other tribes for initial juiciness, first bite impression and muscle fibre and tenderness of the chicken across rearing systems. Consumers scored of the meat from the semi-scavenging system higher (P<0.05) on initial juiciness (4.3 ± 0.20), first bite impression (4.2 ± 0.197), muscle fibre tenderness (4.5 ± 0.217) than meat from the full scavenging chickens. There were positive correlations (0.46) between aroma intensity and overall flavour intensity across both rearing systems. The semi-scavenging system produced better carcass characteristics, lighter (L*) meat and more consumer acceptable meat than full scavenging chickens. Therefore the full scavenging rearing system had better nutrient composition in its scavenging feed resource base, although the semi-scavenging systems produced chickens with better carcass, meat pH, colour and sensory characteristics than the full scavenging chickens.

O presente trabalho objetivou estudar o impacto das variações térmicas durante o armazenamento de carcaças de frango sobre as propriedades funcionais, especialmente a perda de umidade no descongelamento (Drip Loss). Para avaliação destas condições, foram simuladas duas situações: uma comercial, onde um lote de aves abatidas, evisceradas e resfriadas em chiller foram congeladas até -15 (±2)°C e sofreram variações térmicas em ciclos de 8 horas com retirada das mesmas da câmara de estocagem, passando de -15 (±2)°C a -3(±2)°C, momento em que eram novamente devolvidas a câmara de congelamento (situação crítica) e outro lote mantido congelado a -15(±2)°C (situação ideal). Outra condição, chamada de ensaio modelo, foram simuladas 7 faixas de temperatura de armazenamento (0°C, -3°C, -6°C, -9°C, -12°C, -15°C e -18°C) visando definir faixas críticas, baseadas em valores de Drip Loss. Foram definidas 2 faixas: -3°C e -6°C, baseadas em sua proximidade a faixa mais crítica e com valores maiores de Drip Loss (0°C). Para estudo das propriedades funcionais no ensaio comercial, amostra (n=120) de carcaças, divididas em situação ideal (n=60) e situação crítica (n=60) foram descongeladas e submetidas às análises de pH, cor e perda de umidade por descongelamento (Drip Test). Os resultados encontrados mostraram uma tendência (p<0,05) de aumento do Drip Loss com o aumento do tempo de armazenamento na situação crítica, com valores de 4,77(±1,24)% para 3 dias e 10,28(±0,87)% para 120 dias. A situação ideal não apresentou diferenças significativas entre os resultados encontrados, que foram de 5,19(±1,13)% para 3 dias e 4,86(±0,84)% para 120 dias. Para estudo das propriedades funcionais no ensaio modelo, amostras (n=70), em triplicata, de carcaças foram descongeladas e, após a definição das faixas críticas, submetidas às análises de perda umidade por descongelamento (Drip Test), capacidade de retenção de água, análise de perda de umidade no cozimento, quantificação do gel protéico, análise do teor de proteínas no exsudato, análise do perfil protéico do exsudato e análise histológica. Os resultados demonstraram não haver diferenças estatísticas (p<0,05) entre as faixas críticas estudadas (-3°C e -6°C) em relação às propriedades funcionais, com exceção das análises de perda de umidade por descongelamento (Drip Test), onde a mesma tendência de aumento do Drip Loss em relação ao tempo de armazenamento foi encontrada, com valores de 5,85 (±1,16)% para 0 dia e 12,33 (±1,12)% para 70 dias na faixa -3°C e 5,83 (±1,93)% para 0 dia e 10,15 (±0,15)% para 70 dias na faixa -6°C. Concluindo, existem evidências de que as variações térmicas promovem o aumento do Drip Loss em relação a um maior tempo de armazenamento. A constatação deste fato serve como base para estudos mais aprofundados sobre o impacto das condições de armazenamento sobre as propriedades funcionais da carne de frango, bem como para padronizar os processos de congelamento, transporte, distribuição e venda de carne de frango congelada. / The objective of this work was to study the impact of thermal variations during the storage of broiler carcasses on its functional properties, especially the moisture loss during thawing (Drip Loss). In order to evaluate these conditions, two situations were simulated: one called commercial, where a batch of slaughtered, eviscerated and chilled on water system broilers were frozen to -15(±2)°C and divided in two equal batches: one of these batches was called Critical Condition and was maintained in a 8 hour cycle of thermal variation ranging from -15(±2)°C to -3(±2)°C while the other, called Ideal Condition was maintained at -15(±2)°C during all the storage time. In another situation, named Model, seven ranges of storage temperature (0±2°C, -3±2°C, -6±2°C, -9±2°C, -12±2°C, -15±2°C , -18±2°C) were simulated in order to obtain the critical ranges based on the Drip Loss values. Two ranges were found based on its proximity to the most critical range and bigger Drip Loss values: -3±2°C and -6±2°C. For the functional properties studies on the commercial situation, a sample (n=120) of broiler carcasses, equally divided in Critical and Ideal were unfrozen and pH, color and Drip Loss analyzed. The results showed a statistical trend (p<0,05) of increase of Drip Loss values as time of storage increases in the critical condition, with values of 4,77±1,24% for 3 days of storage and 10,28±0,87% for 120 days of storage. The ideal condition didnt showed significant differences among the obtained results that were from 5,19±1,13% for 3 days of storage to 4,86±0,84% for 120 days. For the functional properties studies on the model situation, a sample (n=70), in triplicate, of broiler carcasses was thawed and, after the definition of the critical ranges, it was analyzed for Drip Loss, water holding capacity, moisture loss during cooking, Exudative cooking gel quantification, protein quantification on the exsudate, protein profile on the exudate and histological evaluation. The results showed that there were no statistical differences (p<0,05) between the studied critical ranges (-3±2°C and -6±2°C) in relation to its functional properties, except for Drip Loss values, where a trend of increase in Drip Loss as the time of storage increases was found, with values from 5,85±1,16% for 0 days to 12,33±1,12% for 70 days in range -3±2°C and from 5,83±1,93% for 0 days to 10,15±0,15% for 70 days in range -6±2°C. In conclusion, theres some evidence that the thermal variation can cause the increase of Drip Loss values in relation to an increase of the storage time. All these data can be useful as basis for new studies on functional properties of broiler meat regard to thermal variation during storage, as well as, to standard the processes of freezing, transport, distribution, and retail of frozen broiler meat.

<p>Месо шарана, најзаступљеније врсте рибе на рибњацима у<br />Републици Србији, али и других ципринидних врста, представља<br />значајан нутритивни извор n-3 високо незасићених масних киселина,<br />које имају важну улогу на здравље људи. У раду су испитани<br />фактори који делују на хемијски и маснокиселински састав меса<br />шарана и других ципринидних врста које се гаје на подручју Србије.<br />Установљено је да је садржај масти и маснокисeлински састав риба<br />су под утицајем врсте рибе, чак и када припадају истој фамилији,<br />различитих фактора животне средине, начина гајења, а посебно<br />начина исхране. Утврђен је значај добре технологије производње на<br />рибњаку за одговарајућу структуру планктонских и бентосних<br />организама, што игра велику улогу у добијању меса шарана, али и<br />других ципринидних врста, које се могу гајити у поликултури са<br />њим, доброг хемијског и маснокиселинског састава. Указано је на<br />значај који формулисане смеше имају у исхрани риба на њихово<br />здравствено стање, производне параметре и квалитет меса. Извршено<br />је испитивање замене компоненти анималног порекла са<br />алтернативним компонентама биљног порекла и добијени су<br />задовољавајући резултати у погледу производних перформанси и<br />умерених промена квалитета меса, када је у питању маснокиселински<br />ДВМ Драгана Љубојевић<br />Коришћење репичиног уља у исхрани шарана и лињака као фактора променa квалитета меса<br />iii<br />састав. Анализом седимента, воде у рибњацима, као и меса риба из<br />рибњака и отворених вода установљен је степен загађености животне<br />средине. Представљен је нови производ од меса шарана и других<br />ципринидних риба. По први пут је успостављена ћелијска култура<br />масног ткива шарана, која омогућава анализирање молекуларних и<br />биохемијских механизама који се не могу изучавати на живим<br />рибама, који настају као последица промена у исхрани.</p> / <p>Meso šarana, najzastupljenije vrste ribe na ribnjacima u<br />Republici Srbiji, ali i drugih ciprinidnih vrsta, predstavlja<br />značajan nutritivni izvor n-3 visoko nezasićenih masnih kiselina,<br />koje imaju važnu ulogu na zdravlje ljudi. U radu su ispitani<br />faktori koji deluju na hemijski i masnokiselinski sastav mesa<br />šarana i drugih ciprinidnih vrsta koje se gaje na području Srbije.<br />Ustanovljeno je da je sadržaj masti i masnokiselinski sastav riba<br />su pod uticajem vrste ribe, čak i kada pripadaju istoj familiji,<br />različitih faktora životne sredine, načina gajenja, a posebno<br />načina ishrane. Utvrđen je značaj dobre tehnologije proizvodnje na<br />ribnjaku za odgovarajuću strukturu planktonskih i bentosnih<br />organizama, što igra veliku ulogu u dobijanju mesa šarana, ali i<br />drugih ciprinidnih vrsta, koje se mogu gajiti u polikulturi sa<br />njim, dobrog hemijskog i masnokiselinskog sastava. Ukazano je na<br />značaj koji formulisane smeše imaju u ishrani riba na njihovo<br />zdravstveno stanje, proizvodne parametre i kvalitet mesa. Izvršeno<br />je ispitivanje zamene komponenti animalnog porekla sa<br />alternativnim komponentama biljnog porekla i dobijeni su<br />zadovoljavajući rezultati u pogledu proizvodnih performansi i<br />umerenih promena kvaliteta mesa, kada je u pitanju masnokiselinski<br />DVM Dragana LJubojević<br />Korišćenje repičinog ulja u ishrani šarana i linjaka kao faktora promena kvaliteta mesa<br />iii<br />sastav. Analizom sedimenta, vode u ribnjacima, kao i mesa riba iz<br />ribnjaka i otvorenih voda ustanovljen je stepen zagađenosti životne<br />sredine. Predstavljen je novi proizvod od mesa šarana i drugih<br />ciprinidnih riba. Po prvi put je uspostavljena ćelijska kultura<br />masnog tkiva šarana, koja omogućava analiziranje molekularnih i<br />biohemijskih mehanizama koji se ne mogu izučavati na živim<br />ribama, koji nastaju kao posledica promena u ishrani.</p> / <p>Meat of common carp, the most common fish species which is farmed in<br />the Republic of Serbia and meat of other cyprinid species, represent an<br />important nutritional source of n-3 highly unsaturated fatty acids, which<br />play an important role in human health. This paper examined the factors<br />that affect the chemical and fatty acid composition of carp and other<br />cyprinid species that are grown in Serbia. It was found that the fat content<br />and fatty acid composition of fish are influenced by fish species, even<br />when they belong to the same family, and also by different environmental<br />factors of cultivation, especially by diet. It was established the importance<br />of proper rearing technology in the pond for the appropriate structure of<br />planktonic and benthic organisms, which play a significant role in getting<br />carp meat, and meat of other cyprinid species that can be grown in<br />polyculture with carp of desirable chemical and fatty acid composition. It<br />was pointed out on the significance of formulated feed mixtures in fish<br />nutrition on fish health, production parameters and meat quality. An<br />investigation was done on replacing components of animal origin with<br />alternative components of plant origin and satisfactory results were<br />obtained in terms of production performance and moderate changes in the<br />quality of meat, regarding to fatty acid composition. The degree of<br />environmental pollution was established by analysis of sediment and<br />water in the ponds, and the flesh of fish from ponds and open water. The<br />new food product made from fish meat was presented. For the first time, it<br />was established cell cultures carp preadipocytes, which allows analysis of<br />the molecular and biochemical mechanisms that arise as a result of<br />ДВМ Драгана Љубојевић<br />&nbsp;</p>