Cinqüenta e seis machos inteiros provenientes dos rebanhos do projeto de melhoramento genético da Estação Experimental de Sertãozinho, selecionados ou não para peso aos 378 dias (P 378), nascidos em 1999, foram confinados na Estação Experimental de Colina. Utilizaram-se animais dos grupos genéticos Nelore Seleção (NeS), Nelore Controle (NeC) e Caracu Seleção (Ca), os quais foram distribuídos, aleatoriamente, nas três categorias experimentais: grupo de abate inicial (AI), grupo de alimentação restrita (AR) e grupo de alimentação Ad Libitum (AL). Na categoria AI alocaram-se 4 animais por grupo genético e nas categorias AR e AL foram alocados 8 animais Ca e NeS, e 6 animais NeC. Determinou-se o período experimental pelo tempo de acabamento dos animais, ou seja, quando os garrotes atingiram, no mínimo, 4,0 mm de espessura de gordura subcutânea, avaliada por ultra-som, sobre o músculo Longissimus dorsi, na posição entre a 12 a e a 13 a costelas. Ao término do período de adaptação, a categoria AI foi abatida e as outras duas (AR e AL) entraram no ensaio de alimentação. Repetiram-se as pesagens e medidas de ultra-som e escore corporal a cada 28 dias. Em cada grupo genético, à medida que o acabamento preconizado para cada animal da categoria AL foi atingido, o animal da categoria AR mais semelhante àquele quanto ao peso e condição corporal, no início do experimento, foi também abatido. Avaliaram-se em todos os animais características de carcaça, composição corporal e rendimento de cortes cárneos comerciais. Os dados foram analisados de acordo com esquema fatorial, utilizando dois tipos de alimentação e três grupos genéticos. Os animais Ca e NeS apresentaram maiores pesos de abate, requerendo mais tempo de confinamento para atingirem o ponto de acabamento preconizado. O maior peso de abate destes animais também influenciou outras características correlacionadas, como peso da carcaça, traseiro, dianteiro e ponta de agulha. Verificou-se que a seleção para peso pós-desmame aumentou o peso de abate, de carcaça e de seus cortes primários, porém os animais selecionados apresentaram carne menos macia, mas ainda dentro dos padrões de maciez considerados bons. Os valores médios para os componentes químicos do corpo vazio em porcentagem de água, gordura, proteína e cinzas foram: Ca (60,4; 15,5; 19,7; 4,4), NeS (58,2; 19,4; 17,8; 4,6) e NeC (57,4; 20,2; 18,3; 4,1). As taxas médias de ganho de peso vazio (kg/dia), água (g/dia), gordura (g/dia), proteína (g/dia), cinzas (g/dia) e energia (Mcal/dia) foram: Ca (1,01; 409; 382; 150; 70; 4,45), NeS (1,00; 355; 482; 113; 46; 5,19) e NeC (0,91; 301; 457; 103; 52; 4,91). A composição química média do ganho do corpo vazio, em porcentagem de água, gordura, proteína, cinzas e energia (Mcal/dia) foi: Ca (40,1; 36,8; 15,2; 8,0; 4,32), NeS (35,8; 48,1; 11,3; 4,8; 5,19) e NeC (32,7; 49,5; 12,0; 5,8; 5,36). A seleção para peso pós-desmame, visualizada na comparação entre os grupos Nelore, não promoveu alterações indiretas na composição corporal desses animais, porém aumentou-lhes o tamanho corporal, exigindo maior tempo de confinamento. Os animais Ca, quando comparados aos Nelore apresentaram porcentagens menores de gordura e maiores de proteína no corpo vazio, fato que pode ser explicado pelo maior tamanho corporal desses animais. / Fifty six bulls, born in 1999, from Sertãozinho Experimental Station herds, selected or not for weight at 378 days of age (W 378), were feedlot at Colina Experimental Station. Animals of the genetic groups Nellore (NeS), Control Nellore (NeC) and Caracu (Ca) were utilized. They were randomnly distributed in three experimental groups: initial slaughter group (AI), restricted feeding group (AR) and Ad Libitum feeding group (AL). The AI class had 4 animals for each genetic group and AR and AL had 8 NeS and Ca, and 6 animals NeC. Animals were slaughtered with 4.0 mm of fat thickness measured by ultrasound. After the adaptation period, the AI class was slaughtered and the other classes (AR and AL) started the feedlot period. In each genetic group, when an animal of the AL class attained the desired ultrasonic fat thickness for slaughter, the animal of AR class with similar weight and body conditions score, at the experiment starting point, was also slaughtered. In all animals carcass traits, body composition and meat cuts income were evaluated. Data were analized according to factorial scheme including two type of diets and three genetic groups. The Ca and NeS bulls were heavier at slaughter requiring longer feeding period to attain the desired ultrasonic fat thickness. The heavier weights at slaughter of these animals also changed correlated traits as carcass, hindquater, forequarter and spare ribs weights. The selection for weight in the Nellore promoted higher slaughter, carcass and primary cuts weights, but selected animals had less tender meat, but inside good tender standards. Average values for chemical components of empty body weight, in percentages of water, fat, protein and ash were: Ca (60.4; 15.5; 19.7; 4.4), NeS (58.2; 19.4; 17.8; 4.6) and NeC (57.4; 20.2; 18.3; 4.1). The average rates of empty gain for body weight (kg/day), water (g/day), fat (g/day), protein (g/day), ash (g/day) and energy (Mcal/day) were: Ca (1.01; 409; 382; 150; 70; 4,45), NeS (1.00; 355; 482; 113; 46; 5,19) and NeC (0.91; 301; 457; 103; 52; 4,91). The average rates of empty body gain chemical composition, in percentages of water, fat, protein, ash and energy (Mcal/day) were: Ca (40.1; 36.8; 15.2; 8.0; 4.32), NeS (35.8; 48.1; 11.3; 4.8; 5.19) and NeC (32.7; 49.5; 12.0; 5.8; 5.36). The selection for post-weaning weights, observed by comparing the two Nellore groups, did not promote any change on body composition of these animals, but increased their body size, so they required longer feedlot period. The animals of genetic group Ca, when compared with Nellore, had less fat and more protein, in percentages of empty body. It is due to their larger mature body size.

O presente trabalho teve como objetivo estimar a variabilidade genética existente entre touros e linhagens da raça Nelore, essas representadas pelos grandes genearcas, no que se refere à qualidade de carcaça e de carne. Os animais utilizados para coleta de dados de carcaça e carne pertenciam ao projeto de melhoramento genético e de avaliação para emissão de CEIP - Certificado Especial de Identificação e Produção, da Agro-Pecuária CFM-Ltda, e tinham idade entre 21 e 28 meses. Foram analisadas as características peso de carcaça quente (PCQ), área de olho de lombo (AOL), espessura de gordura subcutânea (EGS) e marmoreio (MAR). A qualidade de carne foi avaliada para os períodos de 7, 14 e 21 dias de maturação, quanto às perdas por exsudação (PE), perdas por cozimento (PC) e maciez (MAC). A avaliação da variabilidade genética entre linhagens foi efetuada com base em valores das diferenças esperadas na progênie (DEP) para as características PCQ, AOL, EGS, MAR e MAC aos 7, 14 e 21 dias de maturação. Foi encontrada variabilidade entre os touros e as linhagens estudadas sugerindo que um progresso genético pode ser conseguido pela seleção de animais para características de carcaça e carne dentro da raça Nelore. / The present study had as objective to estimate the genetic variability between steers and breed lines of Nellore, these represented by the greatest breeders, referred to carcass and beef quality. The animals used to collect the samples of carcass and beef belonged to the project of genetic improvement and evaluation to emission of CEIP-Special Certificate of Identification and Production of CFM Farm-Ltda. The animals had age between 21 and 28 months. Were analyzed the characteristics of hot carcass weight (PCQ), rib eye area (AOL), backfat thickness (EGS), marbling (MAR).The beef quality was evaluated for the periods of 7, 14 and 21 days of ageing, as reference the drip loss (PE), cooking loss (PC) and tenderness (MAC). The evaluation of the genetic variability between the breed lines was done based in the values of the expected progeny differences (DEP) of the characteristics of PCQ, AOL, EGS, MAR and MAC at days 7, 14 and 21 of ageing. There was found a variability between steers and the breed lines studied, suggesting that a genetic process may be possible by selecting the animals to carcass and beef characteristics in the Nellore breed.

The objective of the study was to evaluate meat hygiene practices among meat handlers and microbiological analysis of beef carcasses, slaughtermen hands, equipment and water from low throughput (LTA) and high throughput (HTA) abattoirs in the Eastern Cape Province of South Africa. In stage one of the study, the level of knowledge, practices and attitudes towards meat safety and personal hygiene of slaughtermen were assessed. Forty workers directly involve in beef cattle slaughtering process were surveyed. Data were collected using a structured questionnaire, it contained questions on some of the most important meat safety cues such as knowledge, attitudes, personal hygiene and handling practices. Cross tabulation and Chi-square Test of Association were performed to examine the relationships between the demographic information and the knowledge regarding meat safety using the Statistical Package for Social Sciences (SPSS) version 22. Overall, a significant adherence to basic hygiene practices and a satisfactory level of knowledge were observed. Workers from a HTA yielded comparatively better statistically significant scores. Moreover, knowledge and practices of respondents were significantly associated (P<0.05) due to educational level and professional training. The second stage of the study involved evaluating the level to which cattle carcass, equipment, slaughtermen hands and water were contaminated with Enterobacteriaceae, Salmonella, Escherichia coli and aerobic colony counts (ACC) at different stages during the slaughter process (skinning, evisceration, carcass slitting, inspection, washing and packing). Cattle carcasses were sampled at four sites (rump, neck, flank and brisket) from a LTA (n= 240) and HTA (n= 384) abattoirs. Using conventional biochemical tests, HTA yielded significantly (P<0.05) higher ACC (5.2 log CFU/cm2), E. coli (2.6 log CFU/cm2) and Enterobacteriaceae (2.9 log CFU/cm2) carcass mean scores than LTA after skinning and evisceration. Specific abattoir hygiene differences were noted from washed and chilled carcasses. Salmonella was not detected across all sampled slaughter process stages. In addition, the equipment had bacterial load ranging from 10 to 4 CFU/cm2 for LTA, whereas in HTA this was found to be 7 to 3 CFU/cm2. The bacterial counts for slaughtermen hands were estimated to be 15 to 8 CFU/cm2 in HTA and 10 to 5 CFU/cm2 in LTA. Overall, slaughtermen hands and equipment in the dirty area (skinning and evisceration) yielded more bacterial counts compared to those in the clean area (slitting, inspection, washing and packing) from both abattoirs. For all the sampled carcasses, equipment and slaughtermen hands, HTA yielded comparatively higher (P<0.05) bacterial counts than the LTA. Although the results showed a significant adherence to basic hygiene practices, some aspects such as routine medical examination, health certificates and professional training of slaughtermen still need to be improved. Therefore, these findings show that slaughtermen, equipment and water can be sources of contamination during the slaughter process.

Orientador: Luis Artur Loyola Chardulo / Banca: Maurício Medeiros Cabral / Banca: Mauricio Scoton Igarasi / Banca: Henrique Nunes de Oliveira / Banca: Cyntia Ludovico Martins / Resumo: O objetivo do presente estudo foi identificar as isoformas da Cadeia Pesada de Miosina (Myosin Heavy Chain - MyHC) por eletroforese (SDS-PAGE), nos músculos Semitendinosus por biopsia durante o crescimento e ao abate e no músculo Longissimus dorsi ao abate. Foram utilizados 20 bovinos inteiros da raça Nelore submetidos ao modelo biológico superprecoce em um delineamento inteiramente casualizado. Foi realizada a caracterização morfológica das fibras musculares quanto ao tipo (SO, FOG e FG) e diâmetro nos mesmos músculos. Em relação ao músculo Semitendinosus somente foram identificadas duas bandas da cadeia pesada de miosina, a MyHC do tipo I e a MyHC do tipo II sem diferenciação da isoforma do tipo II e no músculo Longissimus dorsi foram identificadas as isoformas dos tipos I, II a e II x. Quanto a caracterização dos tipos de fibras no músculo Semitendinosus as mesmas estavam distribuídas em mosaico com predomínio de fibras glicolíticas FOG e FG e houve um aumento significativo (P<0,05) da área dos três tipos de fibras da biopsia para o abate. No músculo Longissimus dorsi constatou-se predominância de fibras do tipo FG em relação as fibras do tipo FOG e SO (P<0,05). Também em relação ao diâmetro das mesmas, as fibras SO apresentaram menor diâmetro (P<0,05) em relação aos demais tipos. Comparando-se os dois músculos no abate, observa-se que o músculo Longissimus dorsi apresenta maior área (P<0,05) tanto em relação as fibras SO como quanto as fibras FG. Com relação ao diâmetro observa-se maiores valores (P<0,05) também para as fibras do músculo Longissimus dorsi, principalmente em relação as fibras FG. / Abstract: The objective of this study was identify the myosin heavy chain isoforms in Semitendinosus (biopsy and slaughter) and Longissimus dorsi (slaughter) by electrophoresis (SDS PAGE) and the muscles fiber types (SO, FOG and FG) in Brazilian yearly cattle system - Superprecoce. Were used twenty young bulls Bos indicus (Nellore) in completely randomized design. In relation of Semitendinosus muscle were identified only two MyHC isoforms (type I and II) without any diferentiation of type II, and in the Longissimus dorsi muscle were identified the MyHC isoforms I, II a and II x. About the characterization of fiber types, in the Semitendinosus, the same were distributed in Mosaic with predominance of the FG and FOG fibers and siginificant increase (P<0,05) of the fibers of biopsy to slaughter. In Longissimus dorsi muscle were observed predominance of FG fibers in relation to FOG and SO fibers (P<0,05) and in relation to diameter, the SO fibers showed smallest values. Comparing the two muscles, the Longissimus dorsi, showed high area in relation the SO and FG fibers and high diameter especially in the FG fibers. / Doutor

O presente trabalho teve como objetivo estimar a variabilidade genética existente entre touros e linhagens da raça Nelore, essas representadas pelos grandes genearcas, no que se refere à qualidade de carcaça e de carne. Os animais utilizados para coleta de dados de carcaça e carne pertenciam ao projeto de melhoramento genético e de avaliação para emissão de CEIP - Certificado Especial de Identificação e Produção, da Agro-Pecuária CFM-Ltda, e tinham idade entre 21 e 28 meses. Foram analisadas as características peso de carcaça quente (PCQ), área de olho de lombo (AOL), espessura de gordura subcutânea (EGS) e marmoreio (MAR). A qualidade de carne foi avaliada para os períodos de 7, 14 e 21 dias de maturação, quanto às perdas por exsudação (PE), perdas por cozimento (PC) e maciez (MAC). A avaliação da variabilidade genética entre linhagens foi efetuada com base em valores das diferenças esperadas na progênie (DEP) para as características PCQ, AOL, EGS, MAR e MAC aos 7, 14 e 21 dias de maturação. Foi encontrada variabilidade entre os touros e as linhagens estudadas sugerindo que um progresso genético pode ser conseguido pela seleção de animais para características de carcaça e carne dentro da raça Nelore. / The present study had as objective to estimate the genetic variability between steers and breed lines of Nellore, these represented by the greatest breeders, referred to carcass and beef quality. The animals used to collect the samples of carcass and beef belonged to the project of genetic improvement and evaluation to emission of CEIP-Special Certificate of Identification and Production of CFM Farm-Ltda. The animals had age between 21 and 28 months. Were analyzed the characteristics of hot carcass weight (PCQ), rib eye area (AOL), backfat thickness (EGS), marbling (MAR).The beef quality was evaluated for the periods of 7, 14 and 21 days of ageing, as reference the drip loss (PE), cooking loss (PC) and tenderness (MAC). The evaluation of the genetic variability between the breed lines was done based in the values of the expected progeny differences (DEP) of the characteristics of PCQ, AOL, EGS, MAR and MAC at days 7, 14 and 21 of ageing. There was found a variability between steers and the breed lines studied, suggesting that a genetic process may be possible by selecting the animals to carcass and beef characteristics in the Nellore breed.

Cinqüenta e seis machos inteiros provenientes dos rebanhos do projeto de melhoramento genético da Estação Experimental de Sertãozinho, selecionados ou não para peso aos 378 dias (P 378), nascidos em 1999, foram confinados na Estação Experimental de Colina. Utilizaram-se animais dos grupos genéticos Nelore Seleção (NeS), Nelore Controle (NeC) e Caracu Seleção (Ca), os quais foram distribuídos, aleatoriamente, nas três categorias experimentais: grupo de abate inicial (AI), grupo de alimentação restrita (AR) e grupo de alimentação Ad Libitum (AL). Na categoria AI alocaram-se 4 animais por grupo genético e nas categorias AR e AL foram alocados 8 animais Ca e NeS, e 6 animais NeC. Determinou-se o período experimental pelo tempo de acabamento dos animais, ou seja, quando os garrotes atingiram, no mínimo, 4,0 mm de espessura de gordura subcutânea, avaliada por ultra-som, sobre o músculo Longissimus dorsi, na posição entre a 12 a e a 13 a costelas. Ao término do período de adaptação, a categoria AI foi abatida e as outras duas (AR e AL) entraram no ensaio de alimentação. Repetiram-se as pesagens e medidas de ultra-som e escore corporal a cada 28 dias. Em cada grupo genético, à medida que o acabamento preconizado para cada animal da categoria AL foi atingido, o animal da categoria AR mais semelhante àquele quanto ao peso e condição corporal, no início do experimento, foi também abatido. Avaliaram-se em todos os animais características de carcaça, composição corporal e rendimento de cortes cárneos comerciais. Os dados foram analisados de acordo com esquema fatorial, utilizando dois tipos de alimentação e três grupos genéticos. Os animais Ca e NeS apresentaram maiores pesos de abate, requerendo mais tempo de confinamento para atingirem o ponto de acabamento preconizado. O maior peso de abate destes animais também influenciou outras características correlacionadas, como peso da carcaça, traseiro, dianteiro e ponta de agulha. Verificou-se que a seleção para peso pós-desmame aumentou o peso de abate, de carcaça e de seus cortes primários, porém os animais selecionados apresentaram carne menos macia, mas ainda dentro dos padrões de maciez considerados bons. Os valores médios para os componentes químicos do corpo vazio em porcentagem de água, gordura, proteína e cinzas foram: Ca (60,4; 15,5; 19,7; 4,4), NeS (58,2; 19,4; 17,8; 4,6) e NeC (57,4; 20,2; 18,3; 4,1). As taxas médias de ganho de peso vazio (kg/dia), água (g/dia), gordura (g/dia), proteína (g/dia), cinzas (g/dia) e energia (Mcal/dia) foram: Ca (1,01; 409; 382; 150; 70; 4,45), NeS (1,00; 355; 482; 113; 46; 5,19) e NeC (0,91; 301; 457; 103; 52; 4,91). A composição química média do ganho do corpo vazio, em porcentagem de água, gordura, proteína, cinzas e energia (Mcal/dia) foi: Ca (40,1; 36,8; 15,2; 8,0; 4,32), NeS (35,8; 48,1; 11,3; 4,8; 5,19) e NeC (32,7; 49,5; 12,0; 5,8; 5,36). A seleção para peso pós-desmame, visualizada na comparação entre os grupos Nelore, não promoveu alterações indiretas na composição corporal desses animais, porém aumentou-lhes o tamanho corporal, exigindo maior tempo de confinamento. Os animais Ca, quando comparados aos Nelore apresentaram porcentagens menores de gordura e maiores de proteína no corpo vazio, fato que pode ser explicado pelo maior tamanho corporal desses animais. / Fifty six bulls, born in 1999, from Sertãozinho Experimental Station herds, selected or not for weight at 378 days of age (W 378), were feedlot at Colina Experimental Station. Animals of the genetic groups Nellore (NeS), Control Nellore (NeC) and Caracu (Ca) were utilized. They were randomnly distributed in three experimental groups: initial slaughter group (AI), restricted feeding group (AR) and Ad Libitum feeding group (AL). The AI class had 4 animals for each genetic group and AR and AL had 8 NeS and Ca, and 6 animals NeC. Animals were slaughtered with 4.0 mm of fat thickness measured by ultrasound. After the adaptation period, the AI class was slaughtered and the other classes (AR and AL) started the feedlot period. In each genetic group, when an animal of the AL class attained the desired ultrasonic fat thickness for slaughter, the animal of AR class with similar weight and body conditions score, at the experiment starting point, was also slaughtered. In all animals carcass traits, body composition and meat cuts income were evaluated. Data were analized according to factorial scheme including two type of diets and three genetic groups. The Ca and NeS bulls were heavier at slaughter requiring longer feeding period to attain the desired ultrasonic fat thickness. The heavier weights at slaughter of these animals also changed correlated traits as carcass, hindquater, forequarter and spare ribs weights. The selection for weight in the Nellore promoted higher slaughter, carcass and primary cuts weights, but selected animals had less tender meat, but inside good tender standards. Average values for chemical components of empty body weight, in percentages of water, fat, protein and ash were: Ca (60.4; 15.5; 19.7; 4.4), NeS (58.2; 19.4; 17.8; 4.6) and NeC (57.4; 20.2; 18.3; 4.1). The average rates of empty gain for body weight (kg/day), water (g/day), fat (g/day), protein (g/day), ash (g/day) and energy (Mcal/day) were: Ca (1.01; 409; 382; 150; 70; 4,45), NeS (1.00; 355; 482; 113; 46; 5,19) and NeC (0.91; 301; 457; 103; 52; 4,91). The average rates of empty body gain chemical composition, in percentages of water, fat, protein, ash and energy (Mcal/day) were: Ca (40.1; 36.8; 15.2; 8.0; 4.32), NeS (35.8; 48.1; 11.3; 4.8; 5.19) and NeC (32.7; 49.5; 12.0; 5.8; 5.36). The selection for post-weaning weights, observed by comparing the two Nellore groups, did not promote any change on body composition of these animals, but increased their body size, so they required longer feedlot period. The animals of genetic group Ca, when compared with Nellore, had less fat and more protein, in percentages of empty body. It is due to their larger mature body size.

Thesis (MScAgric)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The aim of this study was to provide scientifically founded guidelines to enhance the understanding of beef production from natural pastures in arid sweet veld regions. Cattle from four breed types ranging from large to small frame sizes (Simmentaler cross > Bonsmara cross > Afrikaner > Nguni) were compared in terms of cow production and efficiency as well as the growth performance, carcass and meat quality of steers slaughtered at 18, 24 and 30 months of age. Eighteen and 30 month old steers were slaughtered at the end of the wet summer season, while the 24 month old steers were slaughtered at the end of the dry winter season. The Afrikaner herd (59.8 ± 9.0 %) had lower (p < 0.05) pregnancy rates than the Simmentaler cross (79.3 ± 12.2 %), Bonsmara cross (76.5 ± 11.1 %) and Nguni herds (86.1 ± 5.8 %). Breed differences (p < 0.05) for weaning weight and preweaning gain were observed (Simmentaler cross > Bonsmara cross > Afrikaner > Nguni). The Nguni cow herd (46.5 ± 5.7 kg/100 kg mated) was more (p < 0.05) efficient than the Simmentaler cross (36.2 ± 5.5 kg/100 kg mated), Bonsmara cross (37.7 kg/100 kg mated) and Afrikaner herds (29.5 ± 5.9 kg/100 kg mated). During the dry winter season steers gained 23.4 ± 1.5 kg from 7 to 12 months of age and from 18 to 24 months of age they gained 20.9 ± 2.0 kg. During the wet summer season steers gained 109.7 ± 1.8 kg from 12 to 18 months and 120.3 ± 4.1 kg from 24 to 30 months of age. The best (p > 0.05) fat classification codes were attained at 30 months of age and the worst (p < 0.05) at 24 months of age. Simmentaler cross steers attained the lowest (p < 0.05) fat classification at all three age classes. At 30 months of age, 15 of the 63 steers slaughtered had 3 or 4 permanent incisors, while 47 steers had 2 permanent incisors. The total amount as well as the percentage kidney and omental fat were the highest (p < 0.05) at 30 months of age and the lowest (p < 0.05) at 24 months. Back fat thickness followed the same pattern. Although breed differences for some meat quality parameters were observed, slaughter age had a much more pronounced effect on meat quality parameters. The percentage cooking loss was the lowest (p < 0.05) at 30 months of age. The meat was also darker (p > 0.05) and more red (p < 0.05) at 30 months than at 18 or 24 months of age. The pH24 was higher (p < 0.05) at 24 (5.68 ± 0.05) and 30 months (5.65 ± 0.03) than at 18 months of age (5.48 ± 0.04). A trained sensory panel only detected that Longissimus muscle samples from 18 month old steers were more tender (p < 0.05) than that from 30 month old steers. Similar results were found for Warner-Bratzler shear force values. Marketing steers at 30 months of age resulted in higher production outputs for all the breed types than marketing weaners. For marketing both weaners and 30 month old steers the Nguni herd produced more marketable kilograms live weight than the Simmentaler cross, the Bonsmara cross and the Afrikaner herds. Different marketing systems suitable to the Arid Sweet Bushveld were identified. Each marketing system is discussed in terms of its application, advantages, disadvantages and adaptability to arid regions. It is maintained throughout that a conservative approach to grazing as well as cattle management is critical to ensure stable production systems in arid regions with erratic rainfall patterns. / AFRIKAANSE OPSOMMING: Die oogmerk van hierdie studie is om wetenskaplik gefundeerde riglyne daar te stel wat die begrip van beesvleis produksie vanaf natuurlike weidings in ariede soetveld streke sal verbeter. Beeste van vier ras tipes wat wissel van groot- tot kleinraam tipes (Simmentaler kruis > Bonsmara kruis > Afrikaner > Nguni) is vergelyk in terme van koeiproduksie en effektiwiteit sowel as die groei prestasie, karkas- en vleiskwaliteit van osse op 18-, 24- en 30-maande ouderdom. Osse wat op 18 en 30 maande ouderdom geslag is, is aan die einde van die nat somerseisoen geslag, terwyl osse wat op 24 maande ouderdom geslag is, aan die einde van die droë winterseisoen geslag is. Die Afrikaner kudde (59.8 ± 9.0 %) het ’n laer (p < 0.05) reproduksietempo as die Simmentaler kruis (79.3 ± 12.2 %), Bonsmara kruis (76.5 ± 11.1 %) en die Nguni kuddes (86.1 ± 5.8 %) gehandhaaf. Ras verskille (p < 0.05) ten opsigte van speenmassas en voorspeense groeitempo’s is waargeneem (Simmentaler kruise > Bonsmara kruise > Afrikaners > Ngunis). Die Nguni koei kudde (46.5 ± 5.7 kg/100 kg gedek) was meer (p < 0.05) effektief as die Simmentalerkruis (36.2 ± 5.5 kg/100 kg gedek), Bonsmarakruis (37.7 kg/100 kg gedek) en die Afrikaner kuddes (29.5 ± 5.9 kg/100 kg gedek). Gedurende die droëwinter seisoen het die osse vanaf 7 to 12 maande ouderdom 23.4 ± 1.5 kg in liggaamsmassa toegeneem en vanaf 18 tot 24 maande ouderdom het hulle 20.9 ± 2.0 kg toegeneem. Gedurende die nat somerseisoen het die osse vanaf 12 tot 18 maande ouderdom 109.7 ± 1.8 kg in liggaamsmassa toegeneem en van 24 tot 30 maande ouderdom het hulle 120.3 ± 4.1 kg toegeneem. Die beste (p < 0.05) vetklassifikasie kodes is op 30 maande ouderdom verkry en die swakste (p < 0.05) op 24 maande ouderdom. Simmentalerkruisosse het by alle ouderdomsgroepe die swakste (P < 0.05) vetklassifikasie kodes behaal. Op 30 maande ouderdom het 15 van die 63 osse wat geslag is 3 of 4 permanente snytande gehad, terwyl 47 osse 2 permanente snytande gehad het. Die totale hoeveelheid sowel as die persentasie nier- en omentumvet was die hoogste (p < 0.05) op 30 maande ouderdom en die laagste (p < 0.05) op 24 maande ouderdom. Rugvetdikte het dieselfde patroon gevolg. Alhoewel rasverskille vir sommige vleiskwaliteitsparameters waargeneem is, het slagouderdom’n groter effek hierop. Die persentasie kookverlies was die laagste (p < 0.05) op 30 maande ouderdom. Die vleis was ook donkerder (p < 0.05) en meer rooi (p < 0.05) op 30 maande ouderdom as op 18 en 24 maande ouderdom. Die pH24 was hoër (p < 0.05) op 24 (5.68 ± 0.05) en 30 maande ouderdom (5.65 ± 0.03) as op 18 maande ouderdom (5.48 ± 0.04). Behalwe vir sagtheid, is geen ander ras- of slagouderdomsverskille in die longissimus spiermonsters vir enige van die sensoriese eienskappe wat geëvalueer is, waargeneem nie. ’n Opgeleide sensoriese paneel het slegs waargeneem dat die longissimus spiermonsters van 18 maand oue osse sagter (p < 0.05) was as dié van 30 maand oue osse. Soortgelyke resulte is vir die Warner-Bratzler snyweerstand gevind. Die bemarking van 30 maand oud osse het hoër produksie uitsette vir al die ras tipes opgelewer as die bemarking van speenkalwers. Met die bemarking van beide speenkalf en 30 maand oue osse, het die Ngunikudde meer bemarkbare kilogram lewendige massa as die Simmentalerkruis, die Bonsmarakruis en die Afrikaner kuddes geproduseer. Verskillende bemarkingstelsels wat as geskik vir die Ariede Soet Bosveld beskou word, is geïdentifiseer. Elke bemarking stelsel is in terme van sy toepassing, voor- en nadele asook die toepaslikheid daarvan in ariede streke bespreek. Dit word deurgaans aanbeveel dat ’n konserwatiewe benadering tot beide weidings- en kuddebestuur, krities is om stabiele produksiestelsels in ariede streke met wisselvalige reënvalpatrone te verseker.

A presente dissertação procurou verificar como os consumidores compreendem o processo de rastreabilidade, que é considerada uma certificação. Também, buscou o entendimento dos consumidores de carne bovina sobre a carne rastreada, verificando como os consumidores valorizam essa carne e identificando elementos para que a rastreabilidade seja apresentada nas gôndolas. A discussão sobre o tema encontra-se embasada sob três aspectos, a rastreabilidade bovina e o seu mercado; a competitividade e a diferenciação dos produtos alimentares, especialmente, as vantagens competitivas de Porter; o marketing, o comportamento e as percepções do consumidor. O método utilizado neste trabalho, em uma primeira fase, baseiase no caráter exploratório e natureza qualitativa, a qual propiciou o desenvolvimento do instrumento da coleta de dados para a fase seguinte. Após realizou-se uma pesquisa descritiva, de natureza quantitativa, dando origem à coleta de dados, ocorrida por uma survey via internet com o auxílio do software Sphinx, obtendo-se uma amostra de 417 consumidores, sendo a maioria dos respondentes gaúchos, residentes em Porto Alegre, com ensino superior e renda acima de R$ 4.000,00. Na análise e discussão dos resultados foram apresentadas as análises estatísticas dos resultados alcançados, classificadas pelos seguintes tópicos: caracterização da amostra, hábitos de consumo, conhecimento sobre diferenciação e certificação, conhecimento sobre rastreabilidade bovina e o consumo da carne bovina rastreada. Os resultados confirmam que a amostra de pesquisa possui um predomínio de consumidores da carne bovina, são conhecedores desta carne, compram preferencialmente em hipermercados, conhecem a carne bovina certificada, consideram-na importante, porém não a exigem. Já, com relação à carne rastreada, consideram-se uma oportunidade de mercado, sendo esta ferramenta de diferenciação e dispõe-se a pagar mais por este tipo de carne. Por fim, demonstrou-se como o consumidor gostaria que a carne rastreada fosse apresentada na gôndola. / The present dissertation has aimed to verify how the consumers know the traceability process that is considered a certification. It has also searched the understanding of beef meat consumers about meat traceability, checking how consumers value this meat, identifying elements so that traceability is presented on the shelves. The discussion about the topic is based on three aspects: bovine traceability and its market; the competitiveness and the differentiation of alimentary products, especially the Porter's competitiveness advantages; the marketing, the consumer's behavior and perceptions. The method employed in this work, in the first stage, is based on the exploratory character and qualitative nature which has provided the development of data collecting instrument for the following stage. Afterwards one has made a descriptive research, of quantitative nature, giving origin to the data collecting, taken place by a survey via internet with the help of Sphinx software, one gaining a sample of 417 consumers, being majority of respondents gaucho's, residents in Porto Alegre, with higher education and income over $ 4,000.00. In the analysis and result discussion the statistical analysis of the results obtained were presented, classified by the following topics: characterization of the sample, consume habits, knowledge about differentiation and certification, knowledge about bovine traceability and consume of the bovine meat traced. The results confirm that the sample of the research has got a predominance in the bovine meat consumers, that are specialist of this meat, buy preferentially in supermarkets, know the bovine meat certified, consider it important although do not demand it. Concerning the traced meat, one considers a market opportunity, being this a differential tool and one predisposes to pay more for this sort of meat. At last, one has demonstrated how the consumer would like that the traced meat was shown on the shelves.

A presente dissertação procurou verificar como os consumidores compreendem o processo de rastreabilidade, que é considerada uma certificação. Também, buscou o entendimento dos consumidores de carne bovina sobre a carne rastreada, verificando como os consumidores valorizam essa carne e identificando elementos para que a rastreabilidade seja apresentada nas gôndolas. A discussão sobre o tema encontra-se embasada sob três aspectos, a rastreabilidade bovina e o seu mercado; a competitividade e a diferenciação dos produtos alimentares, especialmente, as vantagens competitivas de Porter; o marketing, o comportamento e as percepções do consumidor. O método utilizado neste trabalho, em uma primeira fase, baseiase no caráter exploratório e natureza qualitativa, a qual propiciou o desenvolvimento do instrumento da coleta de dados para a fase seguinte. Após realizou-se uma pesquisa descritiva, de natureza quantitativa, dando origem à coleta de dados, ocorrida por uma survey via internet com o auxílio do software Sphinx, obtendo-se uma amostra de 417 consumidores, sendo a maioria dos respondentes gaúchos, residentes em Porto Alegre, com ensino superior e renda acima de R$ 4.000,00. Na análise e discussão dos resultados foram apresentadas as análises estatísticas dos resultados alcançados, classificadas pelos seguintes tópicos: caracterização da amostra, hábitos de consumo, conhecimento sobre diferenciação e certificação, conhecimento sobre rastreabilidade bovina e o consumo da carne bovina rastreada. Os resultados confirmam que a amostra de pesquisa possui um predomínio de consumidores da carne bovina, são conhecedores desta carne, compram preferencialmente em hipermercados, conhecem a carne bovina certificada, consideram-na importante, porém não a exigem. Já, com relação à carne rastreada, consideram-se uma oportunidade de mercado, sendo esta ferramenta de diferenciação e dispõe-se a pagar mais por este tipo de carne. Por fim, demonstrou-se como o consumidor gostaria que a carne rastreada fosse apresentada na gôndola. / The present dissertation has aimed to verify how the consumers know the traceability process that is considered a certification. It has also searched the understanding of beef meat consumers about meat traceability, checking how consumers value this meat, identifying elements so that traceability is presented on the shelves. The discussion about the topic is based on three aspects: bovine traceability and its market; the competitiveness and the differentiation of alimentary products, especially the Porter's competitiveness advantages; the marketing, the consumer's behavior and perceptions. The method employed in this work, in the first stage, is based on the exploratory character and qualitative nature which has provided the development of data collecting instrument for the following stage. Afterwards one has made a descriptive research, of quantitative nature, giving origin to the data collecting, taken place by a survey via internet with the help of Sphinx software, one gaining a sample of 417 consumers, being majority of respondents gaucho's, residents in Porto Alegre, with higher education and income over $ 4,000.00. In the analysis and result discussion the statistical analysis of the results obtained were presented, classified by the following topics: characterization of the sample, consume habits, knowledge about differentiation and certification, knowledge about bovine traceability and consume of the bovine meat traced. The results confirm that the sample of the research has got a predominance in the bovine meat consumers, that are specialist of this meat, buy preferentially in supermarkets, know the bovine meat certified, consider it important although do not demand it. Concerning the traced meat, one considers a market opportunity, being this a differential tool and one predisposes to pay more for this sort of meat. At last, one has demonstrated how the consumer would like that the traced meat was shown on the shelves.

A presente dissertação procurou verificar como os consumidores compreendem o processo de rastreabilidade, que é considerada uma certificação. Também, buscou o entendimento dos consumidores de carne bovina sobre a carne rastreada, verificando como os consumidores valorizam essa carne e identificando elementos para que a rastreabilidade seja apresentada nas gôndolas. A discussão sobre o tema encontra-se embasada sob três aspectos, a rastreabilidade bovina e o seu mercado; a competitividade e a diferenciação dos produtos alimentares, especialmente, as vantagens competitivas de Porter; o marketing, o comportamento e as percepções do consumidor. O método utilizado neste trabalho, em uma primeira fase, baseiase no caráter exploratório e natureza qualitativa, a qual propiciou o desenvolvimento do instrumento da coleta de dados para a fase seguinte. Após realizou-se uma pesquisa descritiva, de natureza quantitativa, dando origem à coleta de dados, ocorrida por uma survey via internet com o auxílio do software Sphinx, obtendo-se uma amostra de 417 consumidores, sendo a maioria dos respondentes gaúchos, residentes em Porto Alegre, com ensino superior e renda acima de R$ 4.000,00. Na análise e discussão dos resultados foram apresentadas as análises estatísticas dos resultados alcançados, classificadas pelos seguintes tópicos: caracterização da amostra, hábitos de consumo, conhecimento sobre diferenciação e certificação, conhecimento sobre rastreabilidade bovina e o consumo da carne bovina rastreada. Os resultados confirmam que a amostra de pesquisa possui um predomínio de consumidores da carne bovina, são conhecedores desta carne, compram preferencialmente em hipermercados, conhecem a carne bovina certificada, consideram-na importante, porém não a exigem. Já, com relação à carne rastreada, consideram-se uma oportunidade de mercado, sendo esta ferramenta de diferenciação e dispõe-se a pagar mais por este tipo de carne. Por fim, demonstrou-se como o consumidor gostaria que a carne rastreada fosse apresentada na gôndola. / The present dissertation has aimed to verify how the consumers know the traceability process that is considered a certification. It has also searched the understanding of beef meat consumers about meat traceability, checking how consumers value this meat, identifying elements so that traceability is presented on the shelves. The discussion about the topic is based on three aspects: bovine traceability and its market; the competitiveness and the differentiation of alimentary products, especially the Porter's competitiveness advantages; the marketing, the consumer's behavior and perceptions. The method employed in this work, in the first stage, is based on the exploratory character and qualitative nature which has provided the development of data collecting instrument for the following stage. Afterwards one has made a descriptive research, of quantitative nature, giving origin to the data collecting, taken place by a survey via internet with the help of Sphinx software, one gaining a sample of 417 consumers, being majority of respondents gaucho's, residents in Porto Alegre, with higher education and income over $ 4,000.00. In the analysis and result discussion the statistical analysis of the results obtained were presented, classified by the following topics: characterization of the sample, consume habits, knowledge about differentiation and certification, knowledge about bovine traceability and consume of the bovine meat traced. The results confirm that the sample of the research has got a predominance in the bovine meat consumers, that are specialist of this meat, buy preferentially in supermarkets, know the bovine meat certified, consider it important although do not demand it. Concerning the traced meat, one considers a market opportunity, being this a differential tool and one predisposes to pay more for this sort of meat. At last, one has demonstrated how the consumer would like that the traced meat was shown on the shelves.