The objective of the study was to determine the antioxidant activity (AA) and the quality of meat from goats and chickens supplemented with Moringa (Moringa oleifera) leaves. For the first experimental chapter, eighteen 9 months old Xhosa lop-eared, castrated goats with an average body weight of 14 kg were used. There were three supplements namely, Moringa oleifera leaves, sunflower cake and grass hay. There were six goats per supplement. The goats were slaughtered after 60 days of supplementation and the Muscularis longissimus thoracis et lumborum (LTL) of the right side of each goat was used to determine fatty acid composition, total phenolic content (TPC), diphenylpicrylhydrazyl (DPPH) assay, 2, 2 azino-bis (3- ethylbenzothiazoline-6-sulphonic diammonium salt (ABTS) assay and reducing power assay of meat. Glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) and lipid peroxidation (thiobarbituric acid reactive substances, TBARS) were taken as parameters to evaluate in vivo AA of the meat. For the second experiment, twelve male broilers were used in four groups of dietary supplementation. Three broilers were allocated per group. After slaughter, the breast muscle was sampled for total phenols, flavonoids, proanthocyanidins, TPC, ABTS, GSH, CAT, SOD, lipid peroxidation, ultimate pH (pH24), colour (L* (lightness), a* (redness), b* (yellowness)), WB-shear force and cooking loss. In both chapters Moringa leaves exhibited the highest AA. Meat from goats supplement with Moringa exhibited the highest AA. Meat from broilers supplemented with a mixture of Moringa leaves, broiler finisher and crushed maize, had the highest (P < 0.05) pH24 and L* values. Moringa can therefore be used to preserve meat without changing the quality of meat.

The aim of this study was to evaluate and compare the influence of conventional and Kosher slaughter techniques in cattle on carcass and meat quality parameters. The conventional slaughter was done using a pneumatic captive bolt gun to stun the animals before sticking, while Kosher slaughter was done by sticking the animals and then stunning them with a 0.22 calibre cash special captive bolt gun, 20 seconds later. The animals (n=311) were randomly assigned into 4 treatment groups, namely; slaughter method (SM) (main group, sub-divided into: conventional slaughter technique (CST) and Kosher slaughter technique (KST)); electrical stimulation (ES), sub-divided into: electrically stimulated (ES) and non-stimulated (NES); gender (G), sub-divided into: male (M) and female (F); fat code (FC), sub-divided into: FC-2 and FC-3 (i.e. lean to medium fatness). The quality attributes evaluated were blood loss (BL), drip loss (DL), cooking loss (CL), presence of blood in the trachea (BLT), blood splash in the lungs (BS), shear force (SF), colour (L*, a* and b*), pH and temperature profile over 24 hours and the effect of subcutaneous fat thickness (SCF). Animals were mainly steers in the “A” age group with an average slaughter weight of about 400 kg. Different crossbreeds of Bonsmara, Brahman and Nguni cattle were used, which is typical of cattle slaughtered in South Africa. Blood loss, blood in trachea and blood splash were evaluated using 311 animals (CST, n=141; KST, n=170) but for the other parameters, smaller numbers were used because of the hectic nature of the trials. Evaluation of BL, BLT and BS were done in the abattoir and pH and temperature readings were also taken at 45 mins, 3, 6, 12 and 24 hrs post-mortem between the 10th and 11th rib on the m. longissimus dorsi which was where the carcasses were sampled for the meat quality analyses. The results of this study revealed that there was no significant difference (p> 0.05) in % blood loss between the conventional and the Kosher group but the conventionally slaughtered group had a slightly higher bleed-out. Fat code had a significant (p= 0.0475) influence on %BL, with FC-2 (2.42%) group bleeding out slightly more than FC-3 (2.24%). For % drip loss, there were no significant differences (p> 0.05) between all the treatment groups except for fat code (p= 0.0242), with FC-3 (2.95%) samples exuding more water than FC-2 (2.42%) meat samples. In terms of % cooking loss, there was a significant difference (p= 0.0004) between the slaughter methods, with meat samples from the conventional method (22.11%) exuding more water than the meat from Kosher group (18.16%). For blood in trachea, there was a highly significant difference (p< 0.0001) between the slaughter methods, with the Kosher-slaughtered animals having significantly more blood in the tracheas than the conventional group. Similarly, for % blood splash, the Kosher-slaughtered group also had a significantly (p< 0.0001) higher amount of splash than the conventional group. In terms of shear force, analyses showed significant difference between the SM with the Kosher meat (42.99) appearing more tender (p= 0.0005) compared to the meat from conventionally slaughtered animals (53.54). Electrical stimulation also had a significant influence, with meat from the ES group (43.27) being significantly (p< 0.0001) more tender compared to the NES group (61.15). For subcutaneous fat thickness, there were no significant differences (p> 0.05) in all the treatments save for fat code, with FC-3 group (6.38) having thicker fat cover (p= 0.0004) than FC-2 (4.44) which was anticipated. In terms of colour, there was a significant difference (p< 0.0001) between slaughter methods for the L* value (lightness). Meat samples from the Kosher-killed animals (46.08) were lighter than the conventionally killed ones (35.40). Samples from the females (48.29) were also significantly lighter (p= 0.0057) than the males’ (37.79). For a* value (redness), there was a significant difference (p< 0.0001) between the slaughter methods. The conventional group meat (15.58), were redder than the Kosher meat (10.40). Gender effect was also significant (p< 0.05), with meat from the males (13.81) appearing redder than the females’ (11.25). For b* value (yellowness), significant difference (p< 0.0001) was also found between the slaughter methods. The Kosher meat samples (-6.49) appeared yellower than those from conventional slaughter (0.26). FC-3 samples (-2.36) were also significantly (p= 0.0112) yellower than the FC-2 samples (-3.05). For pH, analyses revealed a significant difference (p< 0.0380) at 45 minutes post-mortem (pm) between slaughter methods. The kosher carcasses (pH= 6.43) had a slightly higher pH compared to the conventionally slaughtered carcasses (6.33). The ES carcasses (pH=6.16) also had a significantly lower (p< 0.0001) pH compared to the NES carcasses (pH=6.89). At 3hrs pm, only electrical stimulation showed a significant influence (p< 0.0001). The ES carcasses (pH= 5.72) were lower than the NES group (pH= 6.49). At 6hrs, only electrical stimulation still showed a significant influence (p< 0.0001), with the ES carcasses (5.56) still having a faster decline compared to the NES group (pH= 6.01). At 12hrs, the ES group (pH= 5.61) still had a significantly (p= 0.0008) lower pH than the NES group (pH= 5.82). At 24hrs, only the slaughter method showed a significant influence (p= 0.0314) in carcass pH, with the Kosher carcasses (pH= 5.53) having a slightly lower pH compared to the conventionally slaughtered ones (pH= 5.56). The latter difference is probably not of any practical significance and could be ignored. Temperature at 45 minutes pm showed a significant difference (p= 0.0248) between the slaughter methods with the carcasses from Kosher slaughter (36.500C) having a slightly lower temperature compared to those slaughtered conventionally (37.220C). At 3hrs pm, the carcasses from Kosher slaughter (30.060C) had a significantly higher (p= 0.0005) temperature than the conventional group (27.050C). The female carcasses (31.260C) also had significantly higher (p< 0.05) temperature compared to the male carcasses (27.890C). The FC-2 carcasses (28.190C) also had a significantly lower temperature (p= 0.0149) compared to FC-3 (30.110C) which was anticipated due to lower temperature decline in those with lower subcutaneous fat. At 6hrs pm, the conventionally slaughtered carcasses (14.710C) still showed a significantly faster decline (p< 0.0001) compared to those slaughtered by Kosher (20.16). FC-2 carcasses also showed a significantly (p= 0.0104) lower temperature (16.680C) compared to FC-3 (18.740C). At 12 hrs pm, the conventionally slaughtered carcasses (4.720C) still had a significantly (p< 0.0001) lower temperature compared to the Kosher group (10.240C). The FC-2 group (6.690C) also had a significantly (p= 0.0011) lower temperature compared to the FC-3 group (8.890C). Finally at 24 hrs after slaughter, slaughter method still showed a highly significant influence (p< 0.0001) with the conventionally slaughtered carcasses having a much lower temperature (-0.420C) compared to the Kosher group (3.060C). The male’ carcasses (0.620C) also had significantly lower (p< 0.05), ultimate temperature compared to carcasses from the females (2.990C). There was also a significant difference (p< 0.05) between the fat codes, with the FC-2 carcasses (1.010C) showing a lower temperature, compared to the FC-3 (1.710C) carcasses. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Animal and Wildlife Sciences / Unrestricted

This study was part of a larger study to develop an animal production model to obtain the optimum beef tenderness. There is a variety of different beef production systems being used in South Africa. The production systems investigated in this study were; animals reared on pasture until A age classification group (AP), animals reared on pasture until AB age classification group (ABP), animals reared on pasture until B age classification group (BP), animals reared at a feedlot until A age classification group (AF) and animals reared at a feedlot until AB age classification group (ABF). These production systems affect a wide range of components in the muscle that contribute to meat quality. Meat quality refers mainly to tenderness and colour. Scientists and industry role players are uncertain of which production system is the best to produce high quality meat. The aim of the study was to determine the effects of different production systems on the post slaughter muscle energy metabolism and the related effects on meat quality (tenderness and colour). In the experiment 180 steers of the following breed crosses were used: Nguni, Simmental and Brahman. These animals were reared until they reached the A, AB or B age classification, either on pasture or in a feedlot (B only on pasture). All the carcasses were electrically stimulated for approximately 15 sec, before analyses were done. The following properties were measured on the animals after slaughter: tenderness (Warner-Bratzler shear force), carcass pH, carcass temperature, sarcomere lengths, myofibrillar fragmentation length, calpain activity, muscle lactic acid concentration, muscle glycogen concentration, muscle ATP concentration, muscle glucose-6- phosphate concentration, muscle creatine phosphate concentration, muscle glucose concentration, water holding capacity, drip loss and meat colour. These measurements and determinations were done according to standard laboratory procedures at the ARC (Agricultural Research Council) at Irene. Breed had no effect on the muscle energy status for muscle glycolytic potential, muscle lactic acid concentration, muscle glucose concentration, muscle glycogen concentration, muscle glucose-6-phosphate concentration, muscle ATP concentration and creatine phosphate concentration (p>0.05). Older animals from the pasture had lower muscle energy levels than younger animals from the feedlot. Animals from the BP production system had the darkest colour meat with the highest hue angle. AF production system animals had the lightest colour meat with the lowest hue angle and the highest chroma. ABF production system animals had the lowest chroma. Animals from the ABF production system had the lowest shear force value at 1, 7 and 14 days post mortem and animalsfrom the AP production system had the highest shear force value at 1, 7 and 14 days post mortem. This study showed that the energy status in the muscle post mortem does not influence the tenderness of the meat nor the colour (p>0.05). Shear force had a weak to medium positive correlation with muscle pH (between 0.186 and 0.410) and a weak to medium negative correlation with muscle temperature (between -0.157 and -0.268) (p<0.05). Muscle lactic acid concentrations (between -0.033 and -0.322), muscle glucose concentrations (between -0.066 and -0.155) and sarcomere length (between -0.276 and -0.326) had a weak to medium negative correlation with shear force (p<0.05). Muscle glycogen concentrations (between 0.026 and 0.166) and myofibrillar fragment length (between 0.248 and 0.447) had a weak to medium positive correlation with shear force (p<0.05). Shear force had a weak positive correlation with calpastatin activity (between 0.064 and 0.253) and a weak to medium negative correlation with calpain I activity (between -0.183 and -0.313) (p<0.05). The ratio of calpastatin: calpain I (between 0.323 and 0.348) and the ratio of calpastatin: calpain I + II (between 0.183 and 0.275) had a weak to medium positive correlation with shear force (p<0.05). Breed had no effect on the muscle energy status for muscle glycolytic potential, muscle lactic acid concentration, muscle glucose concentration, muscle glycogen concentration, muscle glucose-6-phosphate concentration, muscle ATP concentration and creatine phosphate concentration (p>0.05). If electrical stimulation was not used in this study the difference between the production systems in terms of muscle energy status and colour would have been more prominent. The conclusion is that if animals are slaughtered under “ideal” circumstances in terms of stress being kept to a minimum before slaughter and the carcasses are electrically stimulated in order to prevent cold shortening, the production system shows a small effect on the energy status of the animal and consequently also levels out the meat quality characteristics such as tenderness and colour. For more dramatic results and academic value it would have been more useful to include more variations of non-ideal slaughter conditions and non-electrical stimulation, as well as more breeds. A follow up study with no electrical stimulation can be helpful to explain some uncertainties. This follow up study will present its own challenges, for example higher frequency of DFD. A follow up study on the effects of a larger variety of breeds can help to determine the exact effect ofmuscle energy metabolites in the different breeds, on the tenderness and colour of the meat. Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2012. / Animal and Wildlife Sciences / unrestricted

Orientador: Nelson Jose Beraquet / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-04T01:40:52Z (GMT). No. of bitstreams: 1 Bertoloni_William_D.pdf: 4770148 bytes, checksum: 5dffda950e07402d35c426c8d70bb70a (MD5) Previous issue date: 2005 / Resumo: Diversas pesquisas tem sido realizadas pela comunidade científica com o objetivo de avaliar o bem-estar de suínos durante o abate, entretanto, a maioria destes estudos não representam as condições de abate e constituição genética dos híbridos suínos produzidos e comercializados no Brasil. O presente estudo teve como objetivo principal, avaliar a influência da constituição genética de três híbridos suínos ( A, B e C) e dois sistemas de insensibilização (elétrico e gasoso) na qualidade da carne e bem-estar animal em condições de abate brasileiras. Um total de 956 suínos provenientes de três genéticas (A, B e C) amplamente comercializadas no Brasil com peso vivo de 100 a 120 kg foi aleatoriamente submetido ao sistema de insensibilização elétrico manual comercializado e produzido pela empresa Karl Schermer (220-230/250 volts, 45-60 HZ e 1,4 ¿1,5A) e ao sistema gasoso, modelo COMBI (90 % de CO2), coletivo do tipo compacto comercializado e produzido pela empresa dinamarquesa BUTINA no mesmo abatedouro. Mensurações de pH, cor (L, a*, b*), reflectância luminosa interna (HGP), perda por gotejamento (Drip Loss), capacidade de retenção de água (CRA), ¿umidade exprimivel¿ (Expressible Moisture), salpicamento muscular, escoriações da pele, contusões musculares, fraturas ósseas, reflexos palpebral, níveis plasmáticos de creatina fosfoquinase (CPK), lactato, cortisol e presença de gene halotano foram realizadas em uma amostra dos suínos submetidos aos sistemas de insensibilização estudados. Comparando-se os sistemas de insensibilização, o elétrico demonstrou ser mais estressante, pois os submetidos a esse tratamento apresentaram níveis médios superiores de cortisol (12,23 e 18,55 mcg/dl , p= 0,001) e lactato (142,59 e 158,26 mg/dl , p= 0,0001) para os híbridos A e C em comparação ao sistema gasoso (9,22 e 12,57 mcg/dl ) e (118,09 e 109,68 mg/dl ) respectivamente, entretanto maiores níveis de CPK (p= 0,05) foram obtidos nos híbridos C, quando submetidos ao sistema gasoso (CO2). Variações dos indicadores sanguíneos de estresse entre os híbridos estudados também foram encontradas. Utilizando-se o sistema elétrico valores médios superiores de cortisol (18,55 mcg/dl, p= 0,0001) foram encontrados nos híbridos C quando comparados aos híbridos A (12,23 mcg/dl) e B (10,59 mcg/dl), entretanto, quando o sistema gasoso foi utilizado menores índices de cortisol e CPK foram observados nos híbridos A (9,22 mcg/dl e 1571,29 U/L, p= 0,001) comparativamente aos híbridos B (12,11 mcg/dl e 2641,69 U/L) e C (12,57 e 2789,60 U/L). A presença do genótipo (Nn) foi observada somente nos híbridos B onde níveis elevados de cortisol, lactato e CPK também foram encontrados quando estes animais foram submetidos ao sistema gasoso de insensibilização, entretanto, nas mesmas condições os híbridos C apresentaram elevados níveis de cortisol e CPK similares aos encontrados nos híbridos B, porem não se detectou a presença do genótipo (Nn) nestes animais. Diferenças significativas nos valores médios de luminosidade (L) (p= 0,05), valores (b*) (p= 0,0001), pH 24h pm no pernil (sm) (p= 0,05), pH 24 pm na sobrepaleta (sc) (p= 0,001), reflectância interna 1h pm (p= 0,0001) e reflectância interna 24h pm (p= 0,05) foram encontradas quando os sistemas de insensibilização gasoso e elétrico foram comparados. O sistema de insensibilização gasoso (CO2), apresentou ligeira vantagem em relação aos valores de pH 24h pm do pernil (sm) (5,76 ± 0,18) e sobrepaleta (sc) (6,09 ± 0,27) quando comparado ao elétrico (5,71 ± 0,17) e (6,24 ± 0,18) respectivamente, entretanto, nenhuma diferença significativa nos valores de capacidade de retenção de água, perda por exsudação e ¿umidade exprimível¿ foi observada quando os sistemas de insensibilização elétrico e gasoso foram comparados. A constituição genética dos híbridos avaliados influenciou os valores médios de luminosidade superficial (L) (p= 0,0001), valores (b*) (p= 0,05), pH 24h pm do pernil (sm) (p= 0,0001), reflectância interna 1h pm (p= 0,0001) e reflectância interna 24h pm (p= 0,0001) quando o sistema gasoso foi utilizado para todos os híbridos estudados. Em relação ao sistema de insensibilização elétrico a constituição genética dos híbridos influenciou significativamente os valores de pH do pernil (sm) 24h pm (p= 0,05), pH da sobrepaleta (sc) 24h pm (p= 0,05), reflectância luminosa interna 1h pm (p= 0,0001) e reflectância 24h pm (p= 0,0001). As diferenças nos valores de cor (L, a*, b*), ph 24h no pernil (sm) e sobrepaleta (sc), assim como os valores de reflectância luminosa interna obtidas entre os híbridos A, B e C, quando submetidos aos sistemas de insensibilização estudados não foram suficientes para influenciar significativamente os valores de perda por exsudação, capacidade de retenção de água e ¿umidade exprimível¿ entre os mesmos. Suínos submetidos ao sistema gasoso (híbridos A e B) apresentaram elevados valores médios (b*) (7,16 e 7,42, p= 0,0001) quando comparados aos híbridos insensibilizados com o sistema manual elétrico (5,52 e 5,61), respectivamente. Comparando-se os sistemas elétrico e gasoso de insensibilização independentemente da genética suína estudada, o sistema manual elétrico apresentou índices médios de salpicamento significativamente superiores nas regiões do coxão mole (0,477 e 0,26, p= 0,008), paleta / cranial (0,154 e 0,039, p= 0,003), paleta / central (0,261 e 0,052, p= 0,0002), paleta / caudal (0,180 e 0,030, p= 0,002), lombo / central (0,185 e 0,065, p= 0,01), lombo / caudal (0,06 e 0,207, p= 0,01) e lombo / lateral externa (0,061 e 0,013, p= 0,04). Considerando-se a extensão da musculatura atingida pelo salpicamento, comportamento similar ao encontrado nos índices de intensidade foi observado, ou seja, o sistema manual elétrico apresentou salpicamento mais difuso nas regiões do coxão mole (0,461 e 0,279, p= 0,03), paleta / cranial (0,154 e 0,039, p= 0,003), paleta / central (0,231 e 0,039, p= 0,00002) e paleta / caudal (0,185 e 0,026, p= 0,0008) quando comparado ao sistema gasoso coletivo. Pequena influência da genética suína foi observada tanto na intensidade como na área da musculatura atingida pelo salpicamento, quando o mesmo sistema de insensibilização foi utilizado. Maiores índices de escoriações da pele nas regiões da paleta (1,098 e 0,795, p= 0,0000001), corpo (1,04 e 0,948, p= 0,04) e pernil (0,84 e 0,68, p= 0,001) foram obtidos quando o sistema de insensibilização manual elétrico foi utilizado em comparação ao sistema coletivo gasoso. Nenhuma diferença significativa foi obtida quando se considerou a genética como efeito principal para os índices de escoriações da pele dos híbridos A, B e C insensibilizados como o mesmo sistema. Suínos insensibilizados com o sistema manual elétrico apresentaram maiores índices de reflexo palpebral (11,57%) que os submetidos ao sistema gasoso coletivo (2,86%) de um total de 426 animais avaliados, demonstrando que o sistema manual elétrico foi menos eficaz e proporcionou um nível de narcose inferior ao sistema gasoso durante a sangria. Pequenos índices de fraturas ósseas (< 1%) e contusões musculares (< 2,5%) foram obtidos quando se utilizou ambos os sistemas de insensibilização para todas as genéticas estudadas / Abstract: Several researchers have been accomplished by the scientific community with the goal of evaluating the swine welfare during the stunning, however, most of these studies doesn¿t represent the stunning conditions and genetic background of pigs produced and marketed in Brazil. The present study had as main goal, evaluate the influence of genetic background of three swine hybrids (A, B and C) and two stunning systems (Electric and Gaseous) in the meat quality and welfare animal under the Brazilian slaughterhouse conditions . A total of 956 pigs of three genetics (A, B and C) thoroughly marketed in Brazil with live weight from 100 to 120 kg was randomly submitted to the manual electric stunning system marketed and produced by the company Karl Schermer (220-230/250 volts, 45-60 HZ and 1,4 .1,5A) and to the gaseous collective system, model COMBI (90% of CO2), compact type marketed and produced by the company Danish BUTINA in the same slaughterhouse. Mensurations of pH, color (L, a*, b*), light scattering (HGP), drip loss, water holding capacity, expressible moisture, blood splashed, skin damage, muscular bruises, bones fracture, eyelid reflex, color and intramuscular fat, plasmatic levels of creatine phospokinase (CPK), lactate, cortisol and presence of gene halothane were accomplished in a sample of the swine submitted to the stunning systems studied. Comparing the stunning systems applied, the electric system demonstrated to be more stressful, therefore the pigs submitted to that treatment presented superior medium levels of cortisol (12,23 and 18,55 mcg/dl, p= 0,001) and lactate (142,59 and 158,26 mg/dl, p= 0,0001) for the hybrids A and C in relation to the gaseous system (9,22 and 12,57 mcg/dl) and (118,09 and 109, 68 mg/dl) respectively, although larger CPK levels (p= 0,05) were obtained when the hybrids C was submitted to the gaseous system. Variations of the blood indicators of stress among the hybrids studied were found. When the electric system was used superiors medium levels of cortisol (18,55 mcg/dl, p= 0,0001) were found in the hybrids C when compared to the hybrids A (12,23 mcg/dl) and B (10,59 mcg/dl), by the other hand, when the gaseous system was used the smallest levels of cortisol and CPK were observed in the hybrids A (9,22 mcg/dl and 1571,29 U/L, p= 0,001) comparatively the genetics B (12,11 mcg/dl and 2641,69 U/L) and C (12,57 mcg/dl and 2789,6 U/L) . The presence of the genotype (Nn) was only observed in the hybrids B where high levels of cortisol, lactate and CPK were also found, when stunned with the gaseous system, however, in the same conditions the hybrids C showed similar levels of cortisol and CPK but absence of the (Nn) genotype. Significant differences in the average brightness values (p= 0,05), (b*) (p= 0,0001), pH 24h pm in the ham (sm) (p= 0,05), pH 24h pm in the shoulder (sc) (p= 0,001), light scattering 1h pm (p= 0,0001) and light scattering 24h pm (p= 0,05) were found when the gaseous and electric systems of stunning were compared. The gaseous stunning system in comparison to the electric showed results slightly superiors, presenting better values of pH 24 in the ham (sm) (5,76 ± 0,18) and (5,71± 0,17) and in the shoulder (sc) (6,09 ± 0,27) and (6,24± 0,18), however any significant difference in the values of water holding capacity, drip loss and expressible moisture was observed when both systems were compared. The genetic constitution of the hybrids influenced the medium values of brightness (L) (p= 0,0001), (b*) (p= 0,05), pH 24h pm of the ham (p= 0,0001), light scattering 1h pm (p= 0,0001) and light scattering 24h pm (p= 0,0001) when the gaseous system was used for all the animals studied. In relation to the electric system of stunning, the genetic constitution influenced the pH values of the ham (sm) 24h pm significantly (p= 0,05), pH of the shoulder (sc) 24h pm (p= 0,05), light scattering 1h pm (p= 0,0001) and light scattering 24h pm (p= 0,0001). The significant differences in pH24 pm values of the ham (sm) and shoulder (sc), light scattering and color (L, a*,b*) among the hybrids submitted to the electric and gaseous systems obtained were not enough to influence the values of water holding capacity, drip loss and expressible moisture. Hybrids stunned with the gaseous system (A and B) showed high levels of (b*) values (7,16 and 7,42, p= 0,0001) when compared with other animals of the same genetic stunned with the electric system(5,52 and 5,61), respectively. Comparing the electric and gaseous systems of stunning independently of the breeds studied, the manual electric system presented blood splashed levels significantly superiors in the areas of the inside round (0,477 and 0,26, p= 0,008), shoulder / cranial (0,154 and 0,039, p= 0,003), shoulder / central (0,261 and 0,052, p= 0,0002), palette / caudal (0,180 and 0,030, p= 0,002), loin / central (0,185 and 0,065, p < 0,01), loin / caudal (0,06 and 0,207, p= 0,01) and loin / lateral external (0,061 and 0,013, p= 0,04). Considering the extension of the musculature damaged by the blood splashed the manual electric system also presented more diffuse blood splashed in the areas of inside round (0,461 and 0,279, p= 0,03), shoulder / cranial (0,154 and 0,039, p= 0,003), shoulder / central (0,231 and 0,039, p= 0,00002) and shoulder / caudal (0,185 and 0,026, p= 0,0008) when compared to the collective gaseous system. Small effect of genetic background was observed in the intensity (x) and extension of muscle damaged (y) by the blood splashed when the hybrids were stunned with the same system. Larger skin damage levels in the areas of the shoulder (1,098 and 0,795, p= 0,0000001), body (1,04 and 0,948, p= 0,04) and ham (0,84 and 0,68 , p= 0,001) were obtained when the electric manual system was used in comparison on the gaseous collective system. No significant difference was obtained when was considered the genetics as main effect for the skin damage levels of the hybrids A, B and C stunned with the same system. Pigs stunned with the manual electric system presented larger eyelid reflex levels (11,57%) in comparison the pigs submitted to the collective gaseous system (2,86%), from a total of 426 animal appraised, demonstrating that the manual electric system was less effective and provided a small narcosis level than the gaseous system during the bleeding. Small levels of bone fractures (<1%) and muscular bruises (< 2,5%) were obtained when both stunning systems were utilized for all the studied hybrids / Doutorado / Tecnologia de Alimentos / Doutor em Tecnologia de Alimentos

O objetivo do trabalho foi avaliar o efeito de diferentes períodos de jejum alimentar (3, 6, 9, 12, 15 e 18 horas) sobre a perda de peso vivo em frangos de corte criados em sistema convencional e o rendimento de carcaça quente e fria (antes e após o resfriamento), além de avaliar os atributos de qualidade da carne de peito de frango. Neste experimento foram utilizados frangos de corte da linhagem Ross com 46 dias de idade. Os resultados encontrados mostraram que o tempo de jejum prolongado teve efeito significativo (p&#8804;0,05) sobre a perda de peso das aves antes do abate, com perda de 5% para um jejum de 12h. Conforme os períodos de jejum aumentavam, também incrementava a quantidade de peso perdido na carcaça viva. Registrou-se um elevado rendimento de carcaça quente com um período entre 3 e 6 horas de jejum e reduzido, a partir de um período de 9 horas acusou uma diferença significativa (p&#8804;0,05). A carcaça fria apresentou uma diminuição no seu rendimento, à medida que aumentou o tempo do jejum, com diferença significativa (p&#8804;0,05), que foi observada a partir de 6 horas de jejum. Os resultados encontrados neste estudo não mostraram que o tempo prolongado da privação de alimentos tenha efeito significativo (p&#8804;0,05) sobre a força de cisalhamento (kgf. cm-2) da carne de peito. Quanto à coloração, o aumento do período do jejum alimentar, tornou a carne de peito mais escura, porém não apresentou diferença significativa. Pelos dados da correlação dos atributos de qualidade, foi observada, para o valor de L*, uma relação negativa com o valor do pH da carne, pois, conforme aumentava o pH, o valor de L* diminuía. Observou-se, também, a correlação positiva entre o valor do pH e o CRA. Portanto, à medida que o pH da carne de peito aumentava, a CRA também incrementava. A correlação positiva encontrada entre a perda por cocção e a força de cisalhamento demonstrou que o aumento da perda de peso pela cocção influenciou negativamente a maciez da carne. De acordo com os resultados encontrados em relação ao rendimento de carcaças, o período entre 3 e 9h de jejum alimentar apresentou o melhor resultado. E quanto às qualidades físico-químicas da carne de peito de frango, não se encontrou diferença significativa entre os diferentes períodos de jejum. / The objective of this work was to evaluate the effect of different feed withdrawal periods (3, 6, 9, 12, 15 and 18 hours) on the weight loss of broilers raised in the conventional system and the yield of the hot and cold carcass (before and after cooling), as well as to evaluate the quality attributes of the broilers breast meat. In this experiment, 46-day-old Ross broilers were used. The results found in this study show that the prolonged feed withdrawal time had a significant effect (p&#8804;0,05) on the weight loss of the birds before slaughtering, with a 5% loss for a 12-hour feed withdrawal period. As the feed withdrawal periods increased, so did the amount of weight loss in the living carcass. The hot carcass yield was higher between 3 and 6 hours of feed withdrawal and reduced after 9 hours with a significant difference (p&#8804;0,05). As to the cold carcass yield, it decreased as the fasting time increased, with a significant difference (p&#8804;0,05) on the shear force (kgf. cm-2) of the breast meat. As to coloration, the increase in the feed withdrawal period made the meat darker, but no significant difference was found. According to the data from the quality attributes correlation, a negative correlation was observed between the L* value and the pH of the meat, for as the pH increased, the L* value decreased. A positive correlation was observed between the pH and the WHC, since, as the pH of the breast meat increased, so did the WHC. The positive correlation between the cooking loss and the shear force showed that the increase in the weight loss by the cooking influenced negatively the tenderness of the meat. According to the results found for the carcass yield, the best results were found for the fasting periods between 3 and 9 hours. As to the physical-chemical quality of the chicken breast meat, no significant difference was found among the different feed withdrawal periods.

Este estudo objetivou avaliar a utilização da ultrassonografia no diagnóstico in vivo de wooden breast (WB) em frangos de corte submetidos à restrição alimentar. Foram utilizados 1.800 frangos de corte machos Cobb x Cobb 500 distribuídos em 6 tratamentos, com 12 repetições de 25 aves cada, em um delineamento inteiramente casualizado. Os tratamentos consistiram em restrições de 50, 60, 70, 80, 90% da quantidade de ração fornecida em relação ao consumo ad libitum diário do tratamento controle, de 8 a 49 d. Semanalmente, as aves foram pesadas para avaliação de desempenho e foram submetidas à ultrassonografia para determinar a ecogenicidade do peito, em que os valores de cinza foram calculados a partir do histograma gerado de cada imagem. A profundidade do peito também foi mensurada. Semanalmente, de 7 a 49 d, uma ave por unidade experimental (UE) foi abatida para avaliação visual dos escores de WB, bem como para coleta de amostras de peito para análises sorológicas e de qualidade de carne. Aos 49 d, foram abatidas 5 aves por UE para avaliação do rendimento de carcaça, cortes comerciais e ocorrência de WB Os peitos foram avaliados em escores: peito normal (0); endurecimento suave na parte cranial (1); endurecimento da parte cranial e caudal (2); endurecimento severo de todo o peito (3), endurecimento severo com presença de lesões hemorrágicas e exsudato (4). O efeito das restrições alimentares sobre desempenho e os escores de WB foi avaliado através da análise de variância. Os escores de WB foram considerados variáveis independentes e também correlacionados com as medidas de ultrassom do peito, qualidade de carne, medidas histomorfométricas e perfil sorológico das aves. O desempenho produtivo e a ocorrência de WB reduziram linearmente (P < 0,05) com as restrições alimentares mais severas. Os valores de ecogenicidade e profundidade do peito aumentaram (P < 0,05) com a severidade de WB. De 21 a 49 d, peitos com escores 3 e 4 apresentaram maior perda por cocção, diâmetro de fibra e concentração das enzimas marcadoras de lesão muscular (P < 0,05) comparados ao peito normal (escore 0). A ultrassonografia do peito de frangos de corte pode ser uma ferramenta auxiliar no diagnóstico da miopatia WB em aves vivas. / The present study was conducted to evaluate the effectiveness of utilizing ultrasound (US) images of breast muscle to predict wooden breast (WB) myopathy in lived broilers subjected to different feed restrictions. A total of 1,800 Cobb × Cobb 500 male chicks were fed with 6 treatments and 12 replicates of 25 birds each using a completely randomized design. Birds were fed ad libitum or received 50, 60, 70, 80, and 90% of the quantity consumed by the chickens fed ad libitum. The restriction programs were applied from 8 to 49 d. All birds were banded on the first day and every week they were weighted in order to determined BWG, FCR and FI. Ultrasound images of breast muscle were weekly obtained from all birds to determine echogenicity, where mean gray values were calculated from the obtained histogram, and the breast depth was also measured. One bird per experimental unit was slaughtered every week, from 7 to 49 d, for visual evaluation of WB scores, as well as breast samples collections for serum analysis and meat quality. At 49 d, 5 birds per experimental unit were slaughtered to evaluate carcass yields and WB occurrence Breast were evaluated as: normal breast (0), mild hardening in the upper (1), moderate hardening in the upper and/or lower part of the fillet (2), severe hardening (3), and severe hardening with hemorrhagic lesions and yellow fluid (4). The effect of feed restrictions on growth performance and WB scores was evaluated using ANOVA. The WB scores were considered independent variables and correlated with echogenicity, breast depth, meat quality, histomorphometric measurements and serologic profile of birds. Growth performance as well as carcass yield, decreased linearly (P > 0.05) as feed restriction was applied. The WB occurrence presented linear response to growth performance and it was lower on treatments with higher feed restrictions. Echogenicity and depth increased with WB severity (P < 0.05). From 21 to 49 d, the WB scores 3 and 4 also had higher cooking loss, fiber diameter, serum enzymes, whereas fiber density per area was lower (P < 0.05) compared to normal breasts (score 0). Ultrasound images of broilers breast can be adequately utilized to predict in vivo the WB of birds.

O objetivo desse estudo foi avaliar o efeito do Cloridrato de Zilpaterol (ZH), Ractopamina (RH) e aumento no nível de proteína da dieta, em dois experimentos distintos na dieta de animais Nelore em sistema de confinamento, nas características produtivas, metabólitos sanguíneos, características de carcaça, composição de corpo vazio e ganho, qualidade da carne e expressão gênica. Para isso, foram realizados dois experimentos. O Exp. 1 utilizou 48 machos, não castrados, distribuídos em blocos casualisados em 4 tratamentos em arranjo fatorial 2x2, sendo dois níveis de PB: 100 e 120% e dois níveis de RH: 0 e 300mg/animal/dia. No Exp. 2, foram utilizadas 72 novilhas da raça Nelore distribuídas em delineamento em blocos casualizados. As novilhas foram separadas em dois grupos: Controle (CONT) e Zilpaterol (ZH). Em ambos os experimentos, os animais foram pesados periodicamente e amostras de sangue foram coletadas. Após o abate, o PCQ foi avaliado, amostras da musculatura foram obtidas para análise de PCR. Depois do resfriamento das carcaças, a AOL e EGS foram avaliados, amostras do músculo Longissimus e a sessão entre a 9&ordf; e 11&ordf; costelas foram coletadas. Além disso, no Exp. 2, as novilhas foram abatidas de forma seriada, 0, 20 e 30 dias de suplementação com ZH e no último abate, foi realizada a desossa completa da meia carcaça. A suplementação com RH aumentou o GMD, diminuiu CMS na dieta com PB120, e aumentou a eficiência alimentar, o teor de proteína plasmática e a atividade da ALP na dieta PB120, diminuiu a glicose na dieta PB100. Além disso, a RH diminuiu a FC nas carnes sem maturação e a dieta com 120% de proteína aumentou a FC nas carnes 0 e 7 dias maturadas. No Exp. 2, as novilhas suplementadas com ZH tiveram aumento no GMD, PCQ, EA, creatinina plasmática e diminuição dos AGNE. A composição de corpo vazio foi alterada após 20 dias de suplementação com ZH. O ZH aumentou o ganho de PCV, ganho de proteína e rendimento da maioria dos cortes do traseiro especial. Houve um aumento na FC aos dias 7 e 14 de maturação. O painel sensorial detectou diminuição da maciez da carne de animais alimentados com ZH, independentemente do tempo de maturação, e diminuição a suculência da carne nos tempos 0 e 14 de maturação. O ZH aumentou a expressão das enzimas calpaínas e calpastatina. Os resultados do presente estudo mostram aumento no desempenho produtivo dos animais alimentados com RH e ZH. A suplementação com ZH aumentou o rendimento dos cortes e mudou a composição corporal de ganho. O uso de agonista &#946;-adrenérgico melhora a eficiência do sistema e aumenta a deposição de tecido magro da carcaça, gerando maior rentabilidade por animal abatido / The aim of this study was to evaluate the use of Zilpaterol and Ractopamine Hydrochloride, in two distinct experiments on Nellore diet in feedlot system, for growth performance, serum metabolites, carcass traits, empty body weight composition, carcass gain composition, meat quality and gene expression. The Exp. 1 used 48 bulls, randomly assigned to four treatments in a 2x2 factorial arrangement; two levels of dietary CP: 100% and 120% of metabolizable protein requirement, defined as CP100 and CP120, respectively. Moreover, two levels of RH: 0 and 300 mg/animal/per day. The Exp. 2 used 72 Nellore heifers assigned to a randomized block design. Heifers were separated into 2 groups: Control and Zilpaterol (ZH). In both experiments, the animals were weighed and blood samples were taken periodically. Animals were slaughtered and HCW was recorded, muscle samples were taken to PCR analysis. After chilling, LMA and fat thickness were recorded, longissimus samples and the 911th rib section were obtained. In addition, in the Exp. 2, heifers were sub groups were slaughterer at 0, 20 and 30 days of ZH supplementation, in the last slaughterer, the carcass were debone. Supplementation with RH increased ADG, reduced DMI at CP120, improved G:F, plasma total protein at CP120, also decreased plasma glucose concentration at CP100, and increased ALP activity at CP120. Ractopamine decreased meat shear force, at day 0 of aging. Greater dietary protein increased meat shear force after 0 and 7 days of aging. Heifers fed ZH had gains in ADG, HCW, G:F ratio, increased serum creatinine, and decreased serum NEFA. Zilpaterol increased carcass dressing percentages, and also decreased kidney-pelvic fat. The EBW composition was changed after 20 d of ZH supplementation. The ZH increased EBW gain, EB protein gain, and subprimal yield. There was an increase on WBSF after 7 and 14 d of aging. The sensory panelists reported a decreased on meat tenderness by ZH supplementation, regarding aging time, and a decrease on juciness at 0 and 14 d of aging. The ZH increased the calpain and calpastatin gene expression. These results indicate the efficiency of RAC and ZH to improve the performance,feed efficiency, and muscle mass deposition in Nellore bulls and heifers. Greater CP did not further improved the RAC effect. The ZH supplementation increased the subprimal yield and changed body gain composition. Finally, the use of &#946;-adrenergic agonist increase the beef cattle system&#39;s efficiency by increasing the lean carcass component, with greater profitability per slaughtered animal

Low Atmospheric Pressure Stunning (LAPS) has recently become available to the broiler industry. Therefore, research was conducted to determine the effect of stunning method (LAPS and Electrical Stunning(ES)) and postmortem deboning time (0.75 hr and 4 hr) on the instrumental and sensory acceptability (3 replications) of breast meat (n=576, 144 birds per treatment) prepared using different cooking methods (fried, baked, sous vide). Breast meat was evaluated for pH, CIE L*a*b*, yields, shear force, and consumer acceptability. Postmortem pH decline was more rapid (P<0.05) in the breast meat of LAPS stunned birds when compared to ES stunned birds, but no differences existed (P>0.05) among treatments with respect to final pH. On average, no differences (P > 0.05) existed in the sensory acceptability of fried and sous vide cooked broiler breast treatments. However, for the baked cooking method, the LAPS treatment that was deboned at 4 hr was more acceptable (P<0.05) than other treatments and the ES and LAPS 4 hr postmortem treatments had more acceptable (P<0.05) texture than the ES and LAPS 0.75 hr treatments. Since consumers were highly variable in their liking of chicken breast treatments, consumers were grouped into 6 clusters for each cooking method based on liking and preference. Cluster analysis data revealed that the greatest number of consumers liked all chicken breast treatments, but a larger proportion of consumers liked the 4 hour LAPS and ES treatments when compared to the 0.75 hr LAPS and ES treatments for all cooking methods. In addition, the consumers that indicated that baked chicken breast was highly acceptable preferred (P<0.05) breast meat from the 4 hr LAPS treatment over chicken breast meat from the 4 hr ES treatment. Based on sensory results, chicken breast meat from all stunning and deboning method combinations was highly acceptable to the majority of consumers, but the LAPS 4 hr treatment was slightly more acceptable than other treatments when baked.

No description available.

A pre rigor cut was made through the 12th thoracic vertebrae of one side of a beef carcass, while the other side, processed conventionally, served as the control. The effect of this cut upon yield grade, sensory attributes and tenderness of Longissimus steaks was determined. The treatment caused no differences (P>0.05) in yield grade or in CIE L* a* b* values and oxymyoglobin, reduced myoglobin and metmyoglobin values measured on samples at the treatment site. Sensory panel ratings of visual attributes of color and overall appearance were less desirable (P<0.05) for the treated sides, while for visible texture ratings, there was no significant difference. Purge, cooking loss, percentage moisture, fat and protein, and total collagen were not affected by the treatment (P>0.05). Sarcomere length, and sensory panel ratings of myofibrillar tenderness, connective tissue, and overall tenderness were significantly more desirable for the treated sides. There was no significant difference in fragmentation index or peak force values between treatments, although these values tended to be lower for the treated sides than for the control sides. / Master of Science