Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The production and export of ostrich meat from southern Africa, to especially the European Union, are increasing rapidly due to the healthy nature of ostrich meat. The European Union has very high standards when importing food products, and it is inevitable that more emphasis is being placed on the production of high quality ostrich meat. Another aspect also of concern to consumers, is the welfare of animals prior to slaughter, and this forces producers to look at ways to decrease stress of animals during the ante-mortem period. Research regarding the effect of stress during the ante-mortem period, and as a result, on meat quality, haematology and weight loss in ostriches, is lacking and thus the purpose of this study was to investigate the effect of various transport distances, travel conditions and different birds on these factors. Ante-mortem stress was measured using serum corticosterone levels (ng/ml), heterophil: lymphocyte (H:L) ratio, white blood cell (WBC) count, aspartate aminotransferase (AST) and creatine kinase (CK), as well as the rate and extent of pH decline in the M. gastrocnemius. Special emphasis was also placed on the meat quality parameters drip loss, cooking loss, colour and Warner-Bratzler shear force (kg/1.27 cm diameter). Live weight losses, as well as carcass weight and weight of bruises cut off from each bird were also recorded during various stages of the trials. The effect of transport distance on the meat quality of ostriches was investigated. Ultimate pHu measurements were taken at 24 hours post-mortem. The muscles of the ostriches from the control group (i.e. birds that were not transported prior to slaughter) had a lower mean pHu (5.77 ± 0.053) than birds that travelled 60 (5.93 ± 0.053) and 600 km (6.11 ± 0.053), respectively. Differences in meat drip loss percentage were also observed between the three treatments. The birds in the control group (0.40 ± 0.07 %) had the lowest meat drip loss percentage compared to the birds that travelled 60 km (treatment C) (1.36 ± 0.07 %) and 600 km (treatment B) (0.97 ± 0.07 %), respectively, to a commcerical ostrich abattoir. Ostriches that were transported for 600 km (8.13 ± 1.16 %) had a greater percentage live weight loss during the antemortem period than birds that travelled a distance of 60 km (2.4 ± 2.185 %) to the abattoir, although both groups were deprived of feed for the same period. When the haematology of the groups that travelled different distances was compared at various time intervals in the ante-mortem period, both groups of birds experienced significant increases in WBC, s-AST and s-CK. An increased H:L ratio from pre-transport to post-transport was only evident in the birds that travelled 600 km (treatment B). However, the birds that travelled 60 km were the only group of birds that had significant elevated serum corticosterone levels during the ante-mortem period. The increase in the various blood parameters indicates severe physical stress, which negatively affected meat quality. Another trial also investigated the effect of various farming systems and transport on meat quality and bruising of ostrich carcasses. Ostriches were raised in three different farming systems, i.e. feedlot -, semiintensive - and free range conditions. Other factors that could maybe impact on stress susceptibility, such as road conditions, floorspace and floor type were also investigated. A significant difference in meat pHu was found between ostriches that were raised in a feedlot (5.95 ± 0.018) and semi-intensive (6.04 ± 0.033) environment. The feedlot birds also had the greatest percentage of carcass weight removed due to bruising. The free range birds were the birds that had the lowest floor density per birds and also had the least amount of bruising on their carcasses. Incidently the other two groups (feedlot and semi intensive) were the birds that travelled on the same type of road (mountain pass) in a truck with rubber flooring whilst the free range birds travelled on a straight road in trucks with metal grid floors.The results indicate that the type of farming system didn’t have a significant influence on meat quality of ostriches, but that factors such as road conditions, flooring and bird density did play a significant role in the incidence of bruises and injuries obtained during transport. / AFRIKAANSE OPSOMMING: Die produksie en uitvoer van volstruisvleis vanuit suidelike Afrika, na veral die Europese Unie, is gedurig aan die toeneem as gevolg van die gesonde aard van volstruisvleis. Die Europese Unie het baie hoë standaarde wanneer dit kom by die invoer van voedselprodukte en dit is onvermydelik dat meer klem op die produksie van hoë gehalte volstruisvleis gelê word. ʼn Ander aspek wat ook kommer wek by verbruikers is die welstand van diere voor slagting en hierdie aspek noodsaak produsente om te kyk na maniere om stres te beperk tydens die periode voor slagting. Navorsing rakende die effek van stres tydens die ante-mortem periode, asook vleiskwaliteit, hematologie en gewigsverlies in volstruise as gevolg van vervoer, ontbreek. Die doel van die studie was dus om die invloed van verskillende vervoerafstande, vervoersomstandighede en tipe produksiesisteme op volstruise se stresrespons te ondersoek. Die omvang van ante-mortem stres is bepaal deur die serum-kortikosteroon vlakke (ng/ml), heterofiel: limfosiet (H:L) ratio, witbloedsel (WBS) telling, aspartaat aminotransferase AST en creatien kinase CK, asook die tempo en vlak van pH-daling in die M. gastrocnemius, te meet. Spesiale klem is gelê op die vleisgehalte parameters kookverlies, drupverlies, kleur en Warner-Bratzler-skeurwaardes (kg/1.27 cm deursnee). Gewigsverlies is aangeteken op verskillende stadiums tydens die proewe. Karkasgewigte en die hoeveelheid gewig afgesny van elke volstruiskarkas a.g.v. kneusings is ook bepaal. Die eerste studie het die invloed van vervoerafstand op vleiskwaliteit van slagvolstruise ondersoek. Vleis kwaliteit parameters soos pH, drip verlies, kook verlies, taaiheid en kleur is ondersoek. Die pHu metings is op 24 uur post-mortem geneem. Slagvolstruise in die kontrole groep (d.i. -volstruise wat nie voor slagting vervoer is nie) het ’n laer vleis pHu (5.77 ± 0.05) gehad as voëls wat onderskeidelik 60 km (5.93 ± 0.05) en 600 km (6.11 ± 0.05) ver vervoer is. Verskille in persentasie dripverlies is gesien tussen die vleis van die voëls wat nie vervoer is nie (0.40 ± 0.07 %) en die voëls wat 60 km (1.36 ± 0.07 %) en 600 km ver (0.97 ± 0.07 %) onderskeidelik vervoer is. Volstruise wat vir 600 km (8.13 ± 1.16 %) vervoer is, het ‘n groter persentasie lewende gewig tydens die ante-mortem periode as voëls wat 60 km (2.4 ± 2.19 %) ver vervoer is na die abattoir, verloor, al was beide groepe weerhou van voer vir dieselfde tydperk. Beide groepe wat vervoer is (60 en 600 km) het merkbare toenames in witbloedsel (WBS) tellings, s-AST’s en s-CK’s getoon tydens die ante-mortem periode. Daar is slegs ʼn toename in H:L ratio (ʼn indikator van stres) van voor vervoer tot na vervoer gesien in die voëls wat 600 km vervoer is. Daarteenoor was die voëls wat slegs 60 km vervoer is die enigste voëls wat ʼn toename in korticosteroon vlakke getoon het gedurende die ante-mortem periode. Die toenames is heel moontlik ‘n aanduiding van erge fisiese stres wat ‘n negatiewe effek op vleiskwaliteit het. Die tweede studie het die effek van verskillende produksiesisteme en die stress respons van die verskillende groepe slagvolstuise op vervoer ondersoek. Vleis kwaliteit parameters soos pH, drip verlies, kook verlies en taaiheid is ondersoek. Die hoeveelheid kneusings per volstruis is ook gemeet. Daar was ‘n beduidende verskil (P = 0.009) tussen die pHu van die voerkraal (5.95 ± 0.018) en semi- intensiewe (6.04 ± 0.033) volstruise. Die voerkraal volstruise se vleis het die grootste drip- en kookverliese gehad in vergelyking met die ander twee groepe (semi-intensiewe en ekstensiewe) terwyl die ekstensiewe volstruise die taaiste vleis gehad het. Die voerkraalvoëls het ook die grootste persentasie karkasgewig verloor a.g.v. kneusings wat afgesny is. Die ekstensiewe voëls het die laagste vloer digtheid per volstruis gehad asook die minste kneusings. Die ander twee groepe (voerkraal en semi intensief) was die groepe wat op dieselfde pad vervoer is (bergpas) in vragmotors wat rubber vloere gehad het terwyl die ekstensiewe voêls op ‘n reguit pad vervoer is in ‘n vragmotor met ‘n metaal oppervlakte. Die resultate van die studie is ‘n aanduiding dat die tipe plaassisteem nie ‘n groot impak op die hoeveelheid akute stres ervaar deur die voëls tydens vervoer gehad het of gevolglik op die vleiskwaliteit van die volstruise nie, maar dat faktore soos pad toestand, tipe vloer en voëldigtheid wel ‘n wesenlike rol speel in die voorkoms van kneusings en beserings opgedoen tydens vervoer.

Thesis (MScVoedselwet)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The objective of this investigation was to evaluate the effects of age (adult, sub-adult and lamb), gender (male and female) and production region on the morphological characteristics of springbok (Antidorcas marsupialis). In addition, the effects of the latter on the physical, chemical and sensory quality of the M. longissimus dorsi (LD) muscle were determined. Where applicable, correlations within the various physical and chemical attributes of the meat were verified in the experiments. The sensory ratings of the meat were correlated with the data on the physical and chemical attributes of the LD muscle, where applicable. The mean live mass of male and female adult springbok differed significantly (p < 0.05) and averaged 31.7 ± 0.70 and 28.3 ± 0.60 kg respectively. Gender had no significant effect on the mean live mass of the sub-adult category. The mean dressing percentage of the males (58.83 ± 0.53%) was noted to be significantly higher than that of the females (55.79 ± 0.50%). The lambs (58.98 ± 1.07%) had the highest dressing percentage of all the age categories. An increase in carcass measurements was noted with an increase in animal age. Gender did not have a significant (p > 0.05) effect on the carcass measurements. Inverse correlations were noted between pH24 and drip loss (r = -0.26, p < 0.01) and cooking loss (r = -0.42, p < 0.0001) of the LD muscle. It was noted that stressed animals had a significantly (p < 0.05) higher ultimate pH24 (6.30 ± 0.07), as observed in the meat originating from the Caledon region and this meat consequently had a significantly (p < 0.05) lower cooking loss (27.18 ± 0.62%) and drip loss (1.79 ± 0.08%). Meat shear force values ranged between 1.67 ± 0.05 and 2.67 ± 0.16 kg. 1.27 cm-1 diameter. Age-related effects on tenderness were found to be minor in comparison to pH24 effects. The females (3.13 ± 0.28%) were noted to have a significantly (p < 0.05) higher fat content than the males (1.35 ± 0.08%). The adult (2.45 ± 0.26%) and sub-adult (2.50 ± 0.28%) animals had a significantly higher fat content in comparison with the lambs (1.32 ± 0.11%). The protein content of the springbok meat originating from the four production regions varied between 18.80 ± 0.35 and 21.16 ± 0.51%. Gender had no significant effect on the protein content, except for the meat originating from Rustfontein Nature Reserve where the females had a significantly higher protein content. The two major amino acids noted for springbok LD muscle were glutamic and aspartic acid. Phosphorous was the predominant mineral, followed by potassium and calcium. Production region had a significant (p < 0.05) effect on both the amino acid and mineral content of the meat. The saturated fatty acid (SFA) content of the LD muscle contributed 38.40 to 42.69% of the total identified fatty acids. The poly-unsaturated fatty acid (PUFA) content (36.34 - 40.98%) of the meat was very close to this range, meaning that optimal polyunsaturated to saturated (P:S) ratios (0.96 - 1.18) were present. The effects of age and gender on the fatty acid composition were minor in comparison with regional effects. Warner-Bratzler Shear force (kg. 1.27 cm-1 diameter) values were inversely correlated with the following sensory attributes: tenderness (r = -0.70, p < 0.01), residual tissue (r = -0.68, p < 0.01) and sustained juiciness (r = -0.43, p < 0.05). Decreased acceptance of the meat was noted with an increase in ultimate pH (pH24) from 5.4 to 5.8. As the ultimate pH of the meat increased, the rankings for tenderness (r = -0.46, p < 0.05) and sustained juiciness (r = -0.54, p < 0.05) decreased significantly. / AFRIKAANSE OPSOMMING: Die doel van hierdie ondersoek was om die invloed van ouderdom, geslag en produksie area op die morfologiese eienskappe van springbok (Antidorcas marsupialis) te evalueer. Die effek van laasgenoemde faktore op die fisiese, chemiese en sensoriese kwaliteit van die M. longissimus dorsi (LD) is ook ondersoek. Korrelasies in die fisiese en chemiese eienskappe van die vleis is bestudeer. Die resultate van die sintuiglike evaluering van die vleis is gekorreleer met die fisiese en chemiese data van die LD spier, indien van toepassing. Die gemiddelde gewig van die manlike (31.7 ± 0.70 kg) en vroulike (28.2 ± 0.60 kg) diere het betekenisvol (p < 0.05) verskil. Geslag het geen betekenisvolle effek op die gemiddelde gewig van die sub-volwasse diere getoon nie. Die gemiddelde uitslag persentasie van die manlike diere (58.83 ± 0.53%) was betekenisvol (p < 0.05) hoër in vergelyking met die vroulike diere (55.79 ± 0.50%). Met ‘n toename in ouderdom is ‘n toename in karkas metings waargeneem. Geslag het geen effek op die karkas metings getoon nie. Negatiewe korrelasies is genoteer tussen die finale pH (pH24) en drupverlies (r = -0.26, p < 0.05) en tussen pH24 en kookverlies (r = -0.42, p < 0.0001) van die LD spier. Gestresde diere van die Caledon area het ‘n betekenisvolle (p < 0.05) hoër pH24 (6.30 ± 0.07) getoon en gevolglik ‘n laer (p < 0.05) kookverlies (27.18 ± 0.62%) en drupverlies (1.79 ± 0.08%). Die skeurkrag waardes van die LD spier het gewissel van 1.67 ± 0.05 tot 2.67 ± 0.16 kg. 1.27 cm-1 diameter. Die effek van ouderdom op taaiheid was klein in vergelyking met die effek van pH24. Die vroulike diere (3.13 ± 0.28%) het ‘n hoër (p < 0.05) vetinhoud as die manlike diere (1.35 ± 0.08%) getoon. Die volwasse (2.45 ± 0.26%) en sub-volwasse (2.50 ± 0.28%) diere se vetinhoud was hoër as die van die lammers (1.32 ± 0.11%). The proteininhoud het gewissel van 18.80 ± 0.35 tot 21.16 ± 0.51%. Geslag het geen effek (p > 0.05) getoon op die proteieninhoud, behalwe vir die vleis van die Rustfontein Natuur Reservaat. Glutamien en aspartien suur was kwantitatief die belangrikste aminosure. Fosfor was die belangrikste mineraal, gevolg deur kalium en kalsium. Produksie area het ‘n betekenisvolle (p < 0.05) effek op die aminosuur en mineraalinhoud getoon. Die versadigde vetsuur (SFA) inhoud het gewissel van 38.40 tot 42.69% van die totale geïdentifiseerde vetsure. Die poli-onversadigde vetsuur (PUFA) inhoud het gewissel van 36.34 tot 40.98% en daarom is optimale poli-onversadigde tot versadigde (P:S) verhoudings (0.96 - 1.18) genoteer. Die effek van ouderdom en geslag op die vetsuursamestelling was minimaal in vergelyking met die effek van produksie-area. Warner-Bratzler skeurkrag (kg. 1.27 cm-1 diameter) waardes was negatief gekorreleer met die volgende sensoriese eienskappe: taaiheid (r = -0.70, p < 0.01), residuweefsel (r = -0.68, p < 0.01) en volgehoue sappigheid (r = -0.43, p < 0.05). Daar is ‘n afname in die aanvaarbaarheid van die vleis waargeneem met ‘n toename in pH24 van 5.4 tot 5.8. Met ‘n toename in pH24, het die taaiheid (r = -0.46, p < 0.05) en volgehoue sappigheid (r = -0.54, p < 0.05) van die vleis afgeneem

Master of Science / Department of Food Science / Elizabeth A. Boyle / Animal production factors can affect nutritional composition and quality of poultry meat. Quality attributes and fatty acid composition were evaluated on breast and thigh meat with skin from free range, heritage bred chickens (>116 day of age) (HB) and commercial broilers (<50 day of age) (CM). In addition, sensory and textural attributes were evaluated on breast and thigh meat of HB, and air or water chilled CM. Moisture and fat content was similar (P>0.05) between chicken types without skin. Thigh meat had at least 2.41% more fat (P<0.05) than breast meat; however, breast meat had at least 2.33% more moisture (P<0.05) regardless of skin inclusion or chicken type. Heritage meat with or without skin had a greater amount (P<0.05) of ω3 polyunsaturated fatty acids (PUFA) than CM regardless of chilling type and HB had a lower, more desirable ω6:ω3 ratio of 12.79 when compared to air or water chilled CM at 15.20 and 14.77, respectively. Heritage breast and thigh meat with skin contained 35.60 and 35.21% PUFA which was greater than (P<0.05) CM breast and thigh meat with skin at 20.96 and 20.45%, respectively. Whole carcass weight of CM, breast weight, and bone-in thigh weight was 71.30%, 148.0%, and 52.2% heavier (P<0.05), respectively, than HB weight. However, bone-in thigh yield was 2.1% higher (P<0.05) in HB. Commercial broiler breast and thigh meat was more tender (P<0.05) with higher myofibrillar tenderness and overall tenderness values and having less connective tissue than HB breast and thigh meat. Thigh meat from HB also had the highest (P<0.05) peak force values for Warner-Bratzler (3.47 kgf) and Allo-Kramer (7.22 kgf/g sample) shear tests. Thigh meat was perceived to be more juicy (P<0.05) and have more chicken flavor intensity (P<0.05) than breast meat. Heritage meat showed advantages in fatty acid profiles while CM meat showed advantages in yields and tenderness attributes.

Orientador: Lucia Galvão de Albuquerque / Coorientador: Larissa Fernanda Simielli Fonseca / Banca: Jesus Aparecido Ferro / Banca: Poliana Fernanda Giachetto / Resumo: O conhecimento de mecanismos de regulação de genes associadas a características de qualidade de carne pode colaborar para o entendimento dos processos biológicos envolvidos com esses fenótipos, o que juntamente aos métodos quantitativos já utilizados, poderá auxiliar na seleção de animais mais jovens a um menor custo, tornando viável a inclusão dessas características em programas de melhoramento genético. Apesar dos vários estudos existentes sobre genes diferencialmente expressos, relacionados à qualidade de carne em diferentes espécies, há grande divergência em trabalhos com bovinos, em relação aos genes associados a essas características. Neste contexto, o objetivo do presente trabalho foi validar genes diferencialmente expressos, comuns a diferentes trabalhos de expressão gênica global, encontrados na literatura, relacionados às características de maciez da carne e área de olho de lombo (AOL), em um rebanho comercial de bovinos da raça Nelore. Além disso, verificar se genes diferencialmente expressos seriam traduzidos em proteínas diferencialmente expressas, por meio da técnica de espectrometria de massas avançada (LC-MS/MS). Para isso, foram selecionados 24 animais Nelores extremos para cada característica estudada. Os genes foram escolhidos por meio de buscas realizadas em trabalhos na literatura. Foram selecionados 9 genes (CAPN1, CAPN2, CAST, HSPB1, DNAJ1, FABP4, SCD, ASAH1 e PRKAG3) para maciez da carne e 5 genes (IGF-1, IGF-2, MSTN, NEDD4, UBE4A) para AOL. Para macie... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The knowledge of gene regulation mechanisms associated with meat quality traits may contribute to the understand the biological process involved with these phenotypes, which, jointly with the quantitative methods already used, may help in the selection of younger animals at a lower cost, making viable the inclusion of these traits in animal breeding programs. Despite the several studies on differentially expressed genes related to the meat quality in different species, there is a wide divergence in studies with cattle, regarding to the genes associated with these traits. In this context, the objective of the present work was to validate differentially expressed genes, common in different publications of global gene expression found in the literature, related meat tenderness and rib eye area (REA) in a commercial herd of Nelore cattle. Moreover, to verify if differentially expressed genes would be translated into differentially expressed proteins, by means advanced mass spectrometry technique (LC-MS/MS). For that, 24 extreme Nelore animals for each trait were used. The genes were chosen through searches in publications found in the literature. Were selected nine genes (CAPN1, CAPN2, CAST, HSPB1, DNAJ1, FABP4, SCD, ASAH1 e PRKAG3) for meat tenderness and five genes (IGF-1, IGF-2, MSTN, NEDD4, UBE4A) for REA. For meat tenderness, the genes CAPN1, CAPN2, CAST, HSPB1 e DNAJA1 were up regulated in animals with tough meat. For the REA, just the MSTN gene was up regulated in animals ... (Complete abstract click electronic access below) / Mestre

O objetivo do presente estudo foi avaliar a relação entre indicadores de estresse pré-abate com características de qualidade e metabolismo pós-morte de bovinos terminados em pastagem. Foram colhidas amostras do músculo Longissimus de 55 bovinos da raça Nelore (Bos indicus), não castrados, terminados exclusivamente em pasto. Do total de animais abatidos, foram selecionadas 29 carcaças, de acordo com o pH e classificadas em dois tratamentos: DFD (pH &le; 5.8; n=13) e normal (pH &gt; 5.8; n=16). Durante a sangria, foram colhidas amostras de sangue para as análises de cortisol e de lactato plasmáticos. Foram colhidas amostras do músculo Longissimus thoracis no dia do abate para as análises de metabólitos e pH e 48h após foram retirados dois bifes de 2,5 cm de espessura cada um, para análises instrumentais de qualidade de carne após 0 ou 14 dias de maturação. Não foi observada diferença entre os tratamentos para lactato e cortisol sanguíneos. O pH reduziu com o tempo pós-morte para ambos o tratamentos, porém o tratamento DFD apresentou maiores valores em relação a carne com pH normal. Foi observada uma interação entre os tratamentos e os tempos avaliados para glicogênio (P = 0,006), lactato (P &lt; 0,0001), G-6-P (P &lt; 0,0001) e glicose (P &lt; 0,0001). A concentração de glicogênio diminuiu ao longo do tempo. Os valores de perdas por cocção e força de cisalhamento foram maiores para o tratamento DFD (P = 0,01). Com relação à cor, foi observado maiores valor de L* (P = 0,01) e b* (P = 0,01) para carne DFD. O valor de a* foi maior para a carne normal na carne não maturada, porém após 14 dias o tratamento DFD apresentou maior valor. Foram observadas maiores concentrações de glicogênio muscular nos tempos 8h e 24h, assim como maiores valores de glicose, glicose-6-fosfato e menores concentrações de lactato para o tratamento DFD (P &lt; 0,01). Os indicadores de estresse pré-abate não foram adequados para diferenciar carnes pelo pH final. Diferenças nos valores de pH final não recapitulam o mecanismo esperado de cortes mais escuros para as amostras de alto pH, enquanto que os metabólitos foram associados com diferenças encontradas no pH final, porém o mecanismo responsável por essa diferença não foi determinado. / The objective of the present study was to evaluate the relationship between pre-slaughter stress indicators with quality characteristics and post-mortem metabolism of cattle grazing. Samples of the Longissimus muscle were collected from 55 Nellore (Bos indicus) bovines, non-castrated, exclusively grassfed. From the total of slaughtered animals, 29 carcasses were selected according to pH and classified into two treatments: DFD (pH &le; 5.8, n = 13) and normal (pH&gt; 5.8, n = 16). During slaghter, blood samples were collected for plasma cortisol and lactate analyzes. Samples of the Longissimus thoracis muscle were collected on the day of slaughter for metabolite and pH analyzes and 48 hours after two steaks of 2.5 cm thickness were removed for instrumental analyzes of meat quality after 0 or 14 days of maturation. No difference was observed between treatments for blood lactate and cortisol. The pH reduced with the time after death for both treatments, however the DFD treatment presented higher values in relation to the meat with normal pH. It was observed an interaction between the treatments and the times evaluated for glycogen (P = 0.006), lactate (P &lt;0.0001), G-6-P (P &lt;0.0001) and glucose (P &lt;0.0001). The glycogen concentration decreased overtime. The values of cooking losses and shear force were higher for DFD treatment (P = 0.01). Regarding color, a higher value of L * (P = 0.01) and b * (P = 0.01) was observed for DFD meat. The value of a * was higher for normal meat in the unmated meat, but after 14 days the DFD treatment presented higher value. Higher concentrations of muscle glycogen were observed in 8h and 24h times, as well as higher glucose, glucose-6-phosphate and lower lactate concentrations for DFD treatment (P &lt; 0.01). The pre-slaughter stress indicators were not adequate to differentiate meats by the final pH. Differences in the final pH values did not recapitulate the expected mechanism of darker cuts for the high pH samples, while the metabolites were associated with differences found in the final pH, but the mechanism responsible for this difference was not determined.

O caroço de algodão é uma semente oleaginosa e sua inclusão na alimentação de ruminantes pode aumentar os níveis de ácidos graxos insaturados na carne, melhorando os benefícios potenciais da carne vermelha para a saúde. Contudo, como o tipo de dieta pode influenciar o sabor e aroma e a qualidade da carne produzida é possível que a utilização do caroço de algodão em diferentes níveis na dieta de ovinos confinados altere esses parâmetros. Neste experimento objetivou-se estudar o efeito da adição de diferentes níveis de caroço de algodão e do aquecimento do mesmo no desempenho e características da carcaça e da carne de cordeiros confinados após a desmama. Foram utilizados 36 cordeiros cruzados, 16 machos e 16 fêmeas, em um delineamento de blocos casualizados. O aquecimento do caroço de algodão não causou deterioração lipídica na semente. A utilização de caroço de algodão resultou em maior eficiência alimentar e menor ingestão de matéria seca. As dietas experimentais não alteraram as características de carcaça, a maciez objetiva, a cor e as características organolépticas da carne. Quanto ao perfil de ácidos graxos da carne, o caroço de algodão aumentou o teor saturados e diminuiu os monoinsaturados. O colesterol da carne não foi inflenciado pelos tratamentos alimentares. / Whole cottonseed is an oil seed and its inclusion on ruminants diets could alter meat unsaturated fat levels, thereby improving potential health benefits for the consumer. However, diet type could affect taste, flavour and meat characteristics, and there is a possibility of alteration of these parameters when whole cottonseed is included in different levels on the diet. The aim of this experiment was to evaluate the effects of the inclusion of whole cottonseed in different levels in the diet or the heating of this feed, on the performance, meat and carcass characteristics of lambs after weaning. Thirty-six crossbred lambs, sixteen males and sixteen females, were assigned to a ramdomized block design. The heating of the whole cottonseed failed to induce lipidic deterioration of the seed. Whole cottonseed utilization increased feed efficiency and decreased dry matter intake. Meat characteristics like color, objective tenderness, carcass characteristics and sensory qualities were not affected by treatments. Whole cottonseed increased meat saturated fatty acids and decreased monounsaturated fatty acids. Meat cholesterol were not affect by diets.

A produção de carne de frango no Brasil é um importante setor do agronegócio. O setor passou por décadas de aprimoramentos, culminando desde 2004, no mais alto posto de exportação de carne de frango e ocupando a terceira maior produção mundial. A expansão, conquista e manutenção de novos mercados está inevitavelmente relacionada com a qualidade da matéria-prima. Entre os fatores que influenciam a qualidade do produto final, encontra-se o estresse no manejo pré abate. O presente estudo objetivou estabelecer relações entre a qualidade da carne de frangos e a expressão gênica sob condições de estresse térmico. Para tal, frangos de corte de linhagens comerciais foram submetidos a estresse térmico e abatidos. A carne oriunda dessas aves teve suas propriedades funcionais mensuradas. Os genes expressos de forma diferenciada para a qualidade da carne foram identificados pelo método de arranjos de alta densidade (macroarranjos) e validados com o emprego de PCR quantitativo em tempo real. Para os parâmetros de qualidade de carne avaliados (pH, cor e capacidade de retenção de água), os animais estressados apresentaram peito mais escuro a 1 hora pós abate (valor de L* de 52,46 contra 55,00; p<0,05), menor valor de pH as 24h pós abate (5,82 contra 5,99; p<0,05) e maior capacidade de retenção de água a 1h pós abate (0,29 contra 0,22; p<0,05). O estudo de expressão gênica por macroarranjos de DNA evidenciou um total de 259 genes diferencialmente expressos entre os tratamentos. 149 desses genes apresentaram indução de expressão (p<0,05) nos animais submetidos ao estresse térmico. Alguns desses genes fazem parte da rede de proteínas responsáveis pelo metabolismo energético celular. Lactato desidrogenase A (LDHA), glicose fosfomutase e piruvato quinase são enzimas que atuam na degradação da glicose e demonstraram aumento da expressão sob condição de estresse térmico (p<0,05). Tal fato sugere que durante o estresse térmico, houve uma maior mobilização do glicogênio muscular, fornecendo maior aporte de glicose na célula muscular, acarretando em aumento da taxa glicolítica nesses animais. Outros genes tidos como induzidos pela condição de estresse térmico foram os genes de choque térmico HSP70 e 90 (p<0,05), evidenciando a atividade protetora de suas proteínas na atividade celular frente a condições de elevação da temperatura. Miostatina, Actina 3 e IGF II, proteínas envolvidas no desenvolvimento da musculatura esquelética se apresentaram igualmente elevadas pelas condições de estresse (p<0,05). 9 genes foram selecionados para validação por PCR quantitativo em tempo real. Miostatina, Lactato desidrogenase A, HSP 70 e HSP 90 foram selecionados com base nos resultados obtidos com as hibridizações. Além destes, outros 5 genes foram escolhidos com base na evidência biológica e do papel na resposta fisiológica ao estresse térmico e atividade glicolítica: Glicogênio fosforilase, citrato sintase e lactato desidrogenase B. Miostatina, HSP 70 e 90 e citrato sintase apresentaram maiores níveis de expressão nos animais estressados (p<0,05). Já Glicogênio fosforilase teve sua expressão inibida com o estresse térmico (p<0,05). Esses achados sugerem importante papel do metabolismo energético durante condições de estresse térmico, além da possível influência que a temperatura exerce no desenvolvimento da musculatura esquelética. / Brazilian broiler production yields a considerable amount of income for the nation. Brazil is currently the world&#39;s third broiler producer and the first chicken meat exporter, contributing with 41% of the whole world market. To reach new market frontiers it is inevitable the improvement of meat quality. Among the reasons that influences final products quality is the preslaughter stress. This study scoped establishing the relationships between meat quality and gene expression under thermal stressful conditions. Commercial broiler lines were submitted to high thermal stress prior to slaughter. Breast meat from these animals had their proprieties evaluated. Differentially expressed genes for stressed or non-stressed birds were investigated by macroarrays and further validated by qRT-PCR. Concerning to the meat attributes, breast meat from stressed birds was darker (L* values of 52,46 against 55,00; p<0,05), with lower pH at 24h postmortem (5,82 against 5,99; p<0,05) and had greater water holding capacity 1h after slaughter (0,29 vs. 0,22; p<0,05). Macroarray analysis revealed 259 differentially expressed genes between stressed and non-stressed control birds. From these, 149 were induced by heat stress (p<0,05). Some of these induced genes play a role in carbohydrate metabolism such as lactate dehydrogenase A (LDHA), glucose phosphomutase and piruvate kinase. Such enzymes acts on degradation of glucose in order to provide energy to the muscle cells which has direct effect upon meat quality processing. These findings suggest great mobilization of muscle glycogen stores, offering opportunity of a not efficient muscle-to-meat conversion. Genes that responds to heat stress damage also were induced with heat exposure. That provides a sort of heat tolerance and ensures the birds&#39; survival under heat conditions. Some muscle-related genes were also induced by heat stress. Myostatin, actin 3 and IGFII showed greater amounts of mRNA under this condition (p<0,05). Among all genes differentially expressed, 9 were picked up for further studies with qRT-PCR. Myostatin, lactate dehydrogenase A and B, HSF1, HSF3, HSP70, HSP90, glycogen phosphorylase and citrate synthase were studied and only myostatin, HSP 70 and 90 confirmed the differentially expressed patterns between treatments (p<0,05). Unlikely, glycogen phosphorylase appeared repressed in heat stressed animals (p<0,05). These findings suggest an important role of energetic metabolism of birds at hot environments.

O presente estudo teve como objetivo estimar parâmetros genéticos e fenotípicos de número diâmetro e área de fibras musculares, bem como de características de desempenho, carcaça e qualidade de carne em uma linhagem de frangos pertencentes a um programa de seleção do tipo sib test, onde foram coletadas informações de carcaça dos irmãos completos dos indivíduos a serem selecionados, oriundos de um rebanho de pedigree, fornecidos pela Agroceres Ross Melhoramento de Aves S.A. Também foram fornecidos pela empresa 73.142 e 34.949 dados de peso à seleção juvenil e medidas de ultra-sonografia do músculo peitoral, respectivamente. As características analisadas foram: peso à seleção (PS), medidas de ultra-sonografia (US), peso de peito (PPEI), medida de pH inicial (pHi), medida de pH final (Phf), teor de luminosidade (L*), teor de vermelho (a*), teor de amarelo (b*), perdas de água por exsudação (EXSU), perdas de água por descongelamento (CONG), perdas de água por cozimento (COZ), força de cisalhamento (FC), número de fibras musculares (NCel), diâmetro de fibras musculares (DIAM) e área de fibras musculares (AREA). Os componentes de (co) variância foram estimados através do método de máxima verossimilhança restrita, utilizando-se o programa MTDFREML. A matriz de parentesco foi composta por 77.474 animais. As estimativas dos coeficientes de herdabilidade foram moderadas a altas para as características número de fibras musculares, peso à seleção juvenil, medida de ultra-sonografia, peso de peito, perda de água por exsudação, teor de luminosidade e teor de vermelho. As estimativas de correlações genéticas do número e diâmetro de fibras musculares com as características de perda de água da carne e força de cisalhamento indicaram a existência de uma importante associação genética entre as características, capazes de apresentar satisfatório potencial de resposta à seleção. / This research was conducted to estimate genetic and phenotypic parameters of muscle fibers of number, diameter and area, as well as of performace, carcass and meat quality traits in a male broiler line belonging to a program of selection of the type sib test, in which data from complete brothers of the individuals were selected, bred in a pedigree flock provided by Agroceres Ross Melhoramento de Aves S. A. Also were provided by the company 73,142 and 34,949 data concerning body weight at juvenile selection and ultrasound records of pectoral muscle, respectively. The traits analyzed were: body weight at juvenile selection (PS), ultrasound records of pectoral muscle (US), meat breast weight (PPEI), initial pH measure (pHi), final pH measure (pHf), lightness (L*), redness (a*), yellowness (b*), weep losses (EXSU), drip losses (CONG), shrik losses (COZ), shear force (FC), muscle fibers of number (NCel), muscle fibers of diameter and muscle fibers area (AREA). (Co) variance components were estimated by restricted maximum likelihood method, using the software MTDFREML. The numerator relationship matrix was composed by 77,474 individuals. Heritability coefficients estimates were from moderate to high for muscle fibers number, ultrasound records, meat breast weight, weep losses, lightness and redness traits. Genetic correlation estimates of muscle fibers number and diameter with the measures of meat water losses and shear force traits indicated the existence of an important genetic association between the traits, capable to present potential satisfactory respond to the selection.

Embora a indústria da carne utilize a marinação em larga escala, o comportamento da penetração da salmoura em bifes massageados de carne bovina é pouco conhecido. O músculo Biceps femoris tem sido considerado pouco macio e suculento e apresentado grande variação de maciez intermuscular. Desta forma, o objetivo deste estudo foi avaliar o efeito da marinação com adição de proteína hidrolisada de soja sobre a estrutura muscular de porções distintas do Biceps femoris e suas implicações sobre a qualidade de carne. No Capítulo 2, 3 e 4, seis músculos bovinos foram submetidos aos tratamentos: CONTROLE (bifes não massageados), CS (bifes massageados com salmoura) e SPHS (bifes massageados com salmoura adicionada de proteína hidrolisada de soja). No capítulo 2, os músculos foram divididos em duas porções: Origem (PO) e Inserção (PI), e os tempos de massageamento foram 30 e 60 min. No capítulo 3 e 4, os músculos foram divididos em três porções: Origem (PO), Inserção 1 (PI1) e Inserção 2 (PI2), e os bifes destas porções foram armazenados por 1 e 12 dias após equalização da salmoura, exceto os bifes CONTROLE que foram armazenados somente por 1 dia. As análises realizadas foram: mensuração da penetração da salmoura, determinação do melhor tempo de massageamento, pH, rendimento (REND), colágeno total (CT), composição centesimal, perdas por gotejamento (PPG), perdas por cocção (PPC), força de cisalhamento (FC), microscopia eletrônica de varredura (MEV), análises microbiológicas e sensoriais. O delineamento experimental utilizado foi em blocos inteiramente casualizados, onde cada músculo representou um bloco. A análise de mensuração da penetração da salmoura demonstrou que os bifes SPHS, massageados por maior tempo (60 min), obtiveram maior absorção e retenção de salmoura ao longo da profundidade dos bifes. A PI2 apresentou menor quantidade de CT em comparação às demais, para o CONTROLE. Já os bifes CS e SPHS da PO e PI1 obtiveram menores quantidades de CT em comparação aos bifes destes mesmos tratamentos da PI2. Os bifes massageados não sofreram efeito de tempo de armazenamento e foram mais macios, suculentos e melhor pontuados para impressão global em comparação ao CONTROLE. O pH dos bifes se elevou com os tratamentos CS e SPHS e pareceu influenciar sobre o REND das porções de forma que, a PO obteve menor pH e maior REND, enquanto a PI resultou em maior pH e menor REND. Menores PPG, PPC e FC foram observados para os bifes CS e SPHS e o período de 12 dias de armazenamento permitiu que as PPC e FC diminuíssem. Respostas similares entre a maciez sensorial e objetiva foram observadas nas porções do músculo de forma que, as PIs foram mais macias do que a PO. A analise MEV demonstrou inchaço das fibras e diminuição dos espaços interfibrilares nos bifes massageados CS e SPHS. / Although meat industry uses marination in large-scale, the brine penetration behavior in tumbled steaks from bovines is little known. The Biceps femoris muscle has been considered little tender and juicy, and presented large range of intramuscular tenderness. Therefore, the objective of this work was to evaluate the effect of marination added of hydrolyzed soy protein on the muscular structure of different portions from the Biceps femoris and its implication on beef quality. In Chapter 2, 3 and 4, steaks from six bovine muscles were submitted to the treatments: CONTROL (no tumbling or addition of brine), WTB (with tumbling and addition of brine), and WTB/HSP (with tumbling and addition of brine plus hydrolyzed soy protein). In Chapter 2, the muscles were divided in two portions: Origin (OP) and Insertion (IP), and the tumbling times were 30 and 60 min. In Chapter 3 and 4, the muscles were divided in three portions: Origin (OP), Insertion 1 (IP1) and Insertion 2 (IP2), and their steaks were stored for 1 and 12 days after equalization of brine, except to the CONTROL steaks that were only stored for 1 day. The analyses performed were: monitoring of brine penetration, pH, yield (YIE), total collagen (TC), proximate composition, drip loss (DL), cooking loss (CL), shear force (SF), scanning electron microscopy (SEM), microbiologic and sensory. The experimental design was completely randomized blocks, where each muscle represented one block. The analysis of monitoring of the brine penetration showed that the WTB/HSP steaks, tumbled for largest time (60 min), had higher absorption and retention of brine along the depth of the steaks. The IP2 presented lower TC amount in relation to other portions, in CONTROL steaks. However, the WTB and WTB/HSP steaks from OP and IP1 had lower TC amount when compared to IP2, in these same treatments. The tumbled steaks were not affected by storing time and were tender, juicier and better scored for overall satisfaction with regard to CONTROL steaks. The pH of the steaks was elevated with the WTB and WTB/HSP treatments and appeared to influence the YIE of the portions, where OP had lower pH and higher YIE, while IP resulted in higher pH and lower YIE. Lower DL, CL and SF were observed for WTB and WTB/HSP steaks and the storing time of 12 days allowed that the CL and SF declined. Similar responses between sensory tenderness and SF were observed in the muscle portions, which IPs were tender than OP. The SEM analysis showed swelling of fibers and decrease of spaces between fibrils in tumbled WTB and WTB/HSP steaks

Objetivou-se comparar os parâmetros comportamentais indicativos de estresse, a qualidade da carne e a influência do enriquecimento ambiental em leitões criados no sistema intensivo confinado, de acordo com a qualidade dos tratamentos recebidos. Para isso, foram utilizados 144 leitões divididos em três grupos que receberam tratamentos distintos: 1) Tratamento Aversivo (TA): pessoa se dirigia aos leitões de forma rude, utilizando tom de voz agressivo e fazendo ameaças posturais; 2) Tratamento Controle (TC): pessoa foi cuidadosa ao se movimentar e usou tom de voz suave; 3) Tratamento Misto (TM): os animais receberam TA durante as fases de maternidade e creche e TC durante as fases de crescimento e terminação. Após o desmame, os leitões foram submetidos a testes para aferir medo e verificar se conseguiam reconhecer seu tratador habitual. Foram observados os comportamentos nas mudanças de ambiente, através de instantâneos de 5 min. Na fase de crescimento/terminação, metade dos animais recebeu enriquecimento ambiental. Após o abate foi realizada a análise da qualidade da carne com relação ao seu pH, temperatura, coloração, perda de água por cocção e exsudação. Variáveis como cortisol, lactato, creatina-fosfoquinase, ganho de peso, conversão alimentar e consumo de ração também foram aferidas. O delineamento experimental foi inteiramente casualizado e para a análise dos dados foi utilizado o procedimento PROC MIXED e GLM do programa estatístico SAS. Leitões que receberam tratamento aversivo apresentaram maior frequência de interações agonísticas na maternidade (P=0,01), creche (P=0,04), crescimento/terminação (P=0,0002) e no pré-abate (P=0,06); além de apresentarem maior frequência de belly-nosing no pós-desmame (P=0,001), maior atividade nos testes de medo (P=0,01), menor tempo (P=0,03) e menor frequência (P=0,005) de contato com o novo objeto. Animais que receberam enriquecimento ambiental apresentaram maior frequência do comportamento exploratório (P=0,01). Não houve diferença no ganho de peso, nas análises de qualidade de carne e de sangue (P>0,05), exceto para lactato que apresentou concentrações mais elevadas para animais tratados de forma aversiva (P<0,05). Leitões tratados de forma aversiva demonstraram um padrão comportamental indicando o elevado estresse. A simples cessação deste tratamento não parece ser suficiente para que os animais retomem o padrão comportamental comum à espécie, indicando um efeito residual do tratamento recebido anteriormente. Além disso, estes animais são mais medrosos à novidade, ao isolamento social e ao tratador aversivo. Mesmo não havendo diferença de desempenho e qualidade de carne, estes resultados indicam um empobrecimento do bem-estar desses animais. Por outro lado, quando cessado o tratamento aversivo e adicionado o enriquecimento ambiental, os efeitos residuais do estresse sofrido nas primeiras fases de vida foram suprimidos e os animais apresentaram uma melhoria na resposta ao estresse e no seu bem-estar. / The aim of this work was to compare the behavioral parameters indicative of stress, meat quality and the influence of enrichment in pigs housed in intensive confined system, according to the quality of the treatment received. For this, 144 piglets were separated in three groups with different treatment: 1) Aversive (TA): the person responsible for the treatment was rude with the animals, used an aggressive tone of voice and moved harshly and unpredictably; 2) Control (TC): the person responsible for this treatment was careful to move around as was using a soft tone of voice; 3) Mixed (TM): the animals received TA during farrowing room and nursery, and with TC during growing and finishing phase. After weaning, piglets were tested to assess fear and if they could recognize its usual handler. Behavioral time budgets at each change of phase, was registered by scan sampling every 5-min. In the growing-finishing phase half of the animals received environmental enrichment. After slaughter, meat quality was analysed in relation to their pH, temperature, colour, drip loss, water holding capacity e tenderness. Variables such as cortisol, creatine phosphokinase, weight gain, feed conversion and consumption of solid food were also assessed. The experimental design was randomized and to analyse the data, we used PROC MIXED and GLM procedure of SAS statistical program. Animals TA had more frequency of agonistics interactions at farrowing room (P=0.01), nursery (P=0.04), growing/finishing phase (P=0.0002) and at the day before the slaughter (P=0.06); in addition they had higher frequency of belly-nosing after weaning (P=0.001), higher activity on fear tests (P=0.01), lower time (P=0.03) and lower frequency (P=0.005) of a contact with the novel object. Animal that received environmental enrichment showed more frequency of exploratory behaviour (P=0.01). No difference was found on weight gain, meat quality and blood analysis (P>0.05), but to lactate that was higher to aversive treatment animals (P<0.05). Piglets that received an aversive treatment showed behavioral patterns indicative of higher stress. Finishing the aversive treatment was not enough to this animal restoring their behavioral pattern, indicating a residual effect of the aversive treatment. In addition, these animals were more fearful to novelty, social isolation and the aversive handling. Although there is no difference in performance and meat quality, the results show a poor animal welfare. In other hand, when the treatment was finished and an environmental enrichment was introduced, the residual effect of stress of the farrowing room and nursery were supressed and piglets showed an improvement of behavioral pattern and animal welfare.