Orientador: Antoni Dalmau Bueno / Coorientador: Mateus José Rodrigues Paranhos da Costa / Banca: Flávio Dutra de Resende / Banca: Wignez Henrique / Banca: Maria Lucia Pereira Lima / Banca: Adriano Gomes Páscoa / Resumo: No primeiro capítulo da tese é apresentada uma revisão bibliográfica sobre o assunto, trazendo à tona conceitos importantes sobre estresse e bem-estar animal juntamente com resultados práticos de pesquisas que servem como exemplos dos efeitos do manejo pré-abate de bovinos e do estresse térmico em suínos. O capítulo dois tem como objetivo principal apresentar os fatores de risco associados ao manejo pré-abate de bovinos que estariam relacionados à presença de hematomas e alto pH da carne. As avaliações foram realizadas em dois frigoríficos da região sudeste do Brasil, considerando 15 variáveis medidas durante o manejo pré-abate, utilizando-se 27 661 bovinos. Para transporte, o tipo de veículo, duração da viagem e condições das rodovias foram mensuradas. No desembarque, o tempo de espera para desembarcar os animais, o número de animais que chegaram deitados no caminhão, as batidas lateral e dorsal dos animais contra estruturas do caminhão, a frequência de quedas e o uso de bastão elétrico foram avaliados. Durante o manejo de condução dentro do frigorífico avaliou-se as frequências de quedas dos animais, batidas contra os portões de manejo, uso do bastão elétrico, animais feridos e pisoteados e tamanho do lote conduzido. A frequência e localização dos hematomas nas carcaças e os valores de pH também foram mensurados, juntamente com as categorias animais. Os resultados indicaram alta porcentagem de hematoma nas carcaças (64,14% no frigorífico 1 [F1] e 72,16% no frigorífico 2 [F2]). Também foi encontrada alta porcentagem de pH24 acima de 5,8 (17,67% (F1); 20,30% (F2)). A categoria animal vaca obteve maiores médias de hematomas. Animais transportados por caminhões dois andares, por longas distâncias (mais de 5 horas de viagem) e em condições ruins de estrada obtiveram maiores médias de hematomas também. Durante o desembarque e manejo dos animais dentro... / Abstract: The first chapter presents a literature review, bringing up important concepts about stress and animal welfare using practical results of pre-slaughter handling in cattle and thermal stress management in pigs. Chapter two presents the risk factors associated with transport and pre-slaughter handling in cattle with impact on presence of bruising and high pH meat. The evaluations were performed on two slaughterhouses located in southeastern of Brazil, considering 15 variables measured using 27,661 cattle. For transport, the type of vehicle, journey duration and road condition were assessed. For unloading, the time spent in the queue to unload the animals, number of animals lying in the truck, back and lateral hits at the truck's door, frequency of animals that fell down and were electric prodded were evaluated. During handling procedures the frequencies of animals that fell down, that were hit by the gate, that were electric prodded and the occurrence (yes or no) of injured and trampled animals in the lot, and the number of animals per handling group were measured. Frequency and location of bruises in the carcasses and meat pH were assessed, as well the animal's categories.The results indicated a high percentage of carcass with at least one bruise (64.14% [S1] and 72.16% [S2]) and a high percentage of meat pH greater than 5.8 (17.67% [S1] and 20.30% [S2]). Cows were the category with higher number of bruises. Double decker was the type of vehicle with high risk of bruises. Animals transported for long journeys (up to 5 hours) and in poor road conditions had higher number of bruises too. During unloading and driving procedures, falls had a clear effect in bruises, and electric prod use had an effect in meat pH. Number of animals per handling group also affected meat pH. In chapter three a pig heat stress study was performed during growing and finishing period, evaluating performance, dirt and ... / Doutor

O trabalho tem como objetivo avaliar o perfil morfométrico e o metabolismo post mortem de bovinos Nelore com diferentes taxas de crescimento da desmama ao sobreano. Foram confinados 154 bovinos Nelore, machos não-castrados, com idade média de 18 meses e 350 kg de peso vivo. Os animais foram designados a um delineamento inteiramente casualizado com dois tratamentos (alta taxa de crescimento [ATC] e baixa taxa de crescimento [BTC] da desmama ao sobreano). Foram selecionados cinco animais extremos de ATC e cinco extremos de BTC (10 animais de cada ano) para realização das analises de cor (L*, a*, e b*), força de cisalhamento, perdas por cocção, e também analise do perfil morfométrico muscular. Amostras também foram coletadas para simulação da glicólise in vitro para a determinação de pH, glicose, glicose-6-fosfato e glicogênio nos pontos 0, 0,5, 2, 4, 8, 12 e 24 horas. Os dados foram analisados utilizando o software SAS 9.4. Não houve efeito da taxa de crescimento sobre as características de desempenho, carcaça nem qualidade de carne. Animais BTC apresentaram maior frequência de fibras do tipo I, enquanto animais ATC apresentaram frequência de fibras tipo IIa 4% maior. Em relação à área transversal das fibras musculares, fibras do tipo I provenientes de animais ATC foram 17% maiores. Os animais ATC apresentaram maior concentração de glicogênio nos pontos 0 e 8 horas. Os animais BTC apresentaram maiores concentrações de G6P nos postos 2 e 8 horas. Animais BTC apresentaram maiores concentrações de glicose nos pontos 8 e 24 horas. Em conclusão, a seleção de bovinos com alta taxa de crescimento no período da desmama ao sobreano promove um perfil de fibras mais glicolítico. Entretanto, essa mudança no perfil morfométrico não altera a queda do pH nem a qualidade da carne. / The objective of this study was to evaluate the morphometric profile and the postmortem metabolism of Nellore cattle with different growth rates from weaning to yearling. 154 non castrated Nellore males with 18 mo/old and 350 kg live weight were confined. The animals were assigned to a completely randomized design with two treatments (high growth rate [ATC] and low growth rate [BTC] from weaning to yearling). Five animals from ATC group and five animals from BTC group (10 animal each year) were selected. Analysis of color (L*, a*, and b*), shear force, morphometric profile, simulation of in vitro glycolysis for the determination of pH, glucose, glucose-6-phosphate and glycogen in 0, 0,5, 2, 4, 8, 12 e 24h were performed. The data were analyzed using SAS 9.4 software. There was no effect of growth rate on performance, carcass or meat quality characteristics. BTC Animals had a higher frequency of type I fibers, while ATC animals presented a 4% greater frequency of type IIa fibers. Regarding the cross-sectional area of muscle fibers, Type I fibers from ATC animals were 17% larger. ATC animals showed higher glycogen concentration at 0 h and 8 h. BTC animals had higher concentrations of G6P at 2h and 8h. BTC animals presented higher glucose concentrations at 8 h and 24 h. In conclusion, the selection of cattle with a high growth rate from weaning to yearling leads to a more glycolytic fiber profile. However, this change in the morphometric profile neither alters the pH drop nor the meat quality.

Orientador: Ariel Antonio Mendes / Banca: Roberto de Oliveira Roça / Banca: Marcia Regina Boaro Martins / Banca: Hirasilva Borba / Banca: Rodrigo Garófallo Garcia / Resumo: O objetivo do trabalho foi avaliar as características de qualidades da carne de matrizes pesadas de descarte. Foram realizados três ensaios para se avaliar a qualidade da carne em final de ciclo produtivo. Todas as aves pertenciam a linhagem comercial Ross, procedentes de Uberlândia (MG) e Campo Verde (MT) com idade e peso médio de 479 dias e 3.971g, respectivamente. No Ensaio 1 foram coletados 120 peitos de matrizes em 6 coletas diferentes e avaliados os seguintes parâmetro: pH, cor, valor R, perda por gotejamento, capacidade de retenção de água e absorção de água, capacidade de emulsificação, perdas por cocção e força de cisalhamento. No Ensaio 2 foi realizado o teste sensorial da carne de peito de matrizes comparado a frangos de corte, sendo coletado 20 peitos de matrizes de descarte e 20 peitos de frangos de corte em abatedouro comercial. No Ensaio 3, foram avaliados a composição química, o teor de colesterol e o perfil de ácidos graxos da carne de matrizes pesadas de descarte. A carne de peito de matrizes apresentou valores médios do parâmetro valor de L* de 50,11. Para a capacidade de retenção, perda de peso por cozimento e força de cisalhamento, os valores médios foram 76,67, 17,92% e 4,94kgf/cm2 respectivamente. Na análise sensorial, a carne de matriz apresentou baixa intensidade de maciez (6,9), menor suculência (3,4) e mais elástica, borrachenta e difícil deglutição. A carne de matrizes apresentou percentagem de gordura, proteína, matéria seca, umidade, cinzas e colesterol de 1,39%, 24,26%, 27,71%, 72,29%, 1,42% e 72,59mg/100g, respectivamente. A carne de matrizes pesadas de descarte apresentou boas características de qualidade tecnológicas que possibilitam sua utilização como matéria-prima para a elaboração de industrializados. Além disso, apresentou composição química semelhante a da carne de frangos de corte, não possuindo altos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This present aimed to evaluate the meat quality characterists of spent breeder hens. There were realized three trials to evaluate meat trait of spent breeder hens. All birds were Ross stain, from Uberlândia city (MG) and Campo Verde city (MT) with age and weigth average of 479 days and 3.971g, respectively. In trial 1, there were evaluated: pH, color, R value, drip loss, water holding capacity, water absorption capacity, emulsifying capacity, cooking loss and shear force. In trial 2, it was realized the sensory test using breast meat of breeder hens compared to broiler chicken, collecting 20 spent breeder hen breast and 20 broiler chicken breast cropped in commercial processing plant. In trial 3, there were evaluate the chemistry composition, cholesterol value and fatty acid profile of spent breeder hens meat. Breeder hens meat presented L* value means of 50.11. To water retention capacity, cooking loss and shear force, means values were 76.67, 17.92% e 4.94kgf/cm2, respectively. In sensory test, breeder hens meat presented low intensity tenderness (6.9), lower juiciness (3.4) and elasticier, rubber and difficult to swallow. Breeder hens meat presented percent of fatty, protein, dry material, humidity, material mineral and cholesterol of 1.39%, 24.26%, 27.71%, 72.29%, 1.42% e 72.59mg/100g, respectively. Broiler hen meat presented good technology quality characteristics that it can be possible to use as meat for industry elaborated. Besides, this meat present chemistry composition equal of the meat of broiler chicken, do not hold high value of fat and cholesterol, hence these meat can be consider a meat with healthy characteristics. / Doutor

Orientador: André Mendes Jorge / Coorientador: Flávio Dutra de Resende / Banca: Cristina Andrighetto / Banca: Jaime Urdapilleta Tarouco / Banca: Otávio Rodrigues Machado Neto / Banca: Saulo da Luz e Silva / Resumo: Este estudo teve como objetivo avaliar o efeito do uso de extratos vegetais, vitaminas A, D3 e E, ou sua associação, sobre o temperamento, desempenho produtivo e qualidade de carne de animais confinados. Foram utilizados 56 tourinhos Nelore com 20 meses de idade e peso inicial de 360 (±19,8) kg. Os animais foram inicialmente pesados, blocados por peso corporal inicial e designados aleatoriamente para baias individuais, as quais foram designadas a um dos quatro tratamentos: (C) Controle, suplementados com 48x106, 6x106 e 0,2x106 UI/animal/dia de vitaminas A, D3 e E, respectivamente; (ADE50) Suplementação com dose extra de 50% de vitaminas A, D3 e E (72x106, 9x106 e 0,3x106 UI/ animal/dia; (EV) Suplementação com 0,16% de extratos vegetais (MS do concentrado); (EV+ADE50) Associação da dose extra de vitaminas A, D e E e 0,16% de extratos vegetais. Os animais de todos os tratamentos foram submetidos a mesma dieta diária, com adição de Monensina (30mg / kg de concentrado), variando apenas a inclusão dos diferentes aditivos. O temperamento dos animais foi avaliado de forma a anteceder o momento das pesagens durante as avaliações de desempenho, utilizando-se o escore de tronco (ETr; escala de cinco pontos, onde: 1= calmo e sem movimento; 5= esforços violentos e contínuos) e a velocidade de saída. Os escores individuais de temperamento foram calculados pela média obtida entre o ETr e o escore da velocidade de saída. As pesagens ocorreram no início do confinamento (d0), ao final do período de adaptação (d21) e, posteriormente, a cada 28 dias, totalizando 105 dias de confinamento. Não foram observados efeitos dos tratamentos (P> 0,05) sobre o temperamento dos animais, o mesmo ocorreu com as variáveis de desempenho IMS (9,77; 10,36; 10,49 e 10,04 kg/dia para dietas C, ADE50, EV e EV+ADE50, respectivamente), GMD (1,59; 1,67; 1,69 e 1,64 kg/dia para dietas C, ADE50, EV e EV+ADE50, respectiva ... / Abstract: Fifty-six Nellore (Bos taurus indicus) young bulls of 360 (±19,8) kg initial weight and 20 month of age were used to evaluate the effect of plant extract, vitamins A, D3 supplementation and their associations on the temperament, feedlot performance (finishing phase) and meat quality of Bos indicus cattle. Animals were located in individual pens during 105 days (21 and 84 days, for adaptation and trial period, respectively). Animals were individually weighed, and blocked by initial body weight. Pens within a block were randomly assigned to one of four treatments: (C) Control treatment including 48x106, 6x106 and 0,2x106 IU/animal/day of vitamins A, D3 e E, respectively; (ADE50) Supplemented with 50% extra dose of vitamin A, D3 and E (72x106, 9x106 and 0,3x106 IU/animal/day); (PE) Supplemented with 0.16% (DM basis) of plant extracts; (PE+ADE50) Association of these two additives (50% vitamins A, D3 and E + 0.16% (DM basis) of plant extract). Treatments provided the same diet for all animals (85 and 15%, for concentrate and forage, respectively), varying the inclusion of the different additives. Further, all treatments received monensin (30 mg/kg of concentrate). Feed offered was daily monitored as well as feed refusals were collected and weighed to determine DMI and feed efficiency (F:G). Temperament scores were evaluated before performance evaluation using averaging CS and exit score. Animals were classified within temperament type according to temperament score [average < 3= adequate temperament (ADQ); average > 3 = excited temperament (EXC)]. Animals were weighed when they arrived at the feedlot (d0), in the end of the adaptation phase (d21) and every 28 days after, during 105 days. Treatments did not affected the animals' temperament (P > 0.05). No effects of treatments were observed for DMI (9.77; 10.36; 10.49 e 10.04 kg/day for diets C, ADE50, PE and PE+ADE59, respectively), ADG (1.59; 1.67; 1... / Doutor

Orientador: Luis Arthur Loyola Chardulo / Banca: Antonio Carlos Silveira / Banca: Albino Luchiari Filho / Resumo: O experimento foi realizado no Setor de Confinamento de Gado de Corte da Faculdade de Medicina Veterinária e Zootecnia e no Laboratório de Bioquímica de Proteínas do Instituto de Biociências. Foram utilizados animais da raça Nelore, mestiços u Aberdeen X Nelore e mestiços u Simental X Nelore, abatidos com idade entre 12 e 15 meses conforme estabelecido pelo modelo biológico superprecoce. O experimento foi conduzido em um delineamento inteiramente casualizado. O objetivo do presente estudo foi análise de componentes da maciez de novilhos superprecoces de grupos genéticos distintos. Não foi verificada diferença estatística (p>0,01) entre os grupos genéticos para a força de cisalhamento, Índice de Fragmentação Miofibrilar (MFI) e frações do colágeno, entretanto houve influência (p<0,01) do período postmortem, exceto para o colágeno. A carne de animais abatidos entre 12 e 15 meses de idade apresenta atributos de qualidade independente do grupo genético utilizado e com sete dias de maturação todos os animais apresentaram carne com grau de maciez desejável. / Abstract: The experiment was accomplished in the Section of Feedlot of cattle of Faculdade de Medicina Veterinária e Zootecnia and in the Laboratório de Bioquímica de Proteínas do Instituito de Biociências. Nelore breed, u Aberdeen X Nelore crossbreed and u Simental X Nelore crossbreed were used and slaughtered accordingly with the brazilian system called "superprecoce". The experiment was accomplished in a completely randomized design. The objective of the present study was the evaluation of tenderness components of "superprecoce" of different genetic groups. There was no statistics difference (p>0,01) between genetic groups for the shear force values, Myofibrillar Fragmentation Index (MFI) and collagen, however there was influence (p<0,01) of the ageing, except for the collagen. The meat of animals slaughtered between 12 and 15 months of age showed attributes of quality independent of the genetic group and with seven days of ageing all animals had a desirable tenderness. / Mestre

Made available in DSpace on 2016-04-28T14:59:46Z (GMT). No. of bitstreams: 1 2009 - Renata de Oliveira Santos Ramalho.pdf: 151905 bytes, checksum: 3e6bc90df190c2dc80a5b2ac16eb37fd (MD5) Previous issue date: 2009-02-13 / The objective of the present study was to compare the fatty acids (FA) profile in Longissimus dorsi (LDM) muscle of bovine Nelore and F1 Sindi Nelore. A completely randomized experimental design in 2 x 2 factorial arrangements (two genetic groups and two ages - 36 and 48 months) was used. Sixteen young bulls (eight Nelore and eight F1 Sindhi Nellore), castrated were used. Animals were fed the same diet and were slaughtered at average live weight of 460.0 (10.1) kg. The FA profile was determined by gas chromatography with high resolution, within a universe of 14 FA, and monounsaturated fatty acids (MFA), polyunsaturated fatty acids (PUFAs), total saturated fatty acids (SFA) and total unsaturated fatty acids (UFA). The animals F1 Sindi Nelore presented smaller concentration of the fatty acid saturated mirystic (0.88%), in comparison with the Nelore (1.31%). There was not interaction (P>0.05) among genetic group and age for studied SFA. The palmitic acid presented larger concentration among SFA. Among the monounsaturated there was significant difference (P <0.05) among the genetic groups for the palmitoleic acid, that had 0.63 percentage points the more for the animals Nelore. The oleic acid presented larger concentration in the meat of the two genetic groups, with 41.44% for the Nelore and 41.38% for F1 Sindi Nelore, followed by the linoleic acid , with 6.15% for the Nelore and 4.86% for F1 Sindi Nelore. There was not statistical difference (P>0.05) for monounsaturated total or for the unsaturated total among the genetic groups. There was no interaction (P>0.05) among genetic group and age for the monounsaturated and polyunsaturated. There was difference (P <0.05) for the ration &#969;6: &#969;3. F1 Sindi Nelore obtained smaller ration &#969;6: &#969;3. the smallest concentration of acid mirystic and the smallest ration &#969;6: &#969;3 in the meat of bovine F1 Sindi Nelore checks makes the meat of this breed healthier considering the fatty acids profile. / O objetivo do presente trabalho foi comparar o perfil de ?cidos graxos (AG) do m?sculo Longissimus dorsi (MLD) de bovinos Nelore e F1 Sindi Nelore. O delineamento experimental foi o inteiramente casualizado em um esquema fatorial 2 x 2 (dois grupos gen?ticos e duas idades - 36 e 48 meses). Foram utilizados 16 novilhos, 8 Nelore e 8 F1 Sindi Nelore, castrados, que receberam a mesma dieta e foram abatidos com peso vivo m?dio de 460,0 (10,1) kg. O perfil de AG foi determinado por cromatografia gasosa de alta resolu??o, dentro de um universo de 14 AG, entre ?cidos graxos monoinsaturados (AGM), ?cidos graxos poliinsaturados (AGPI), total de ?cidos graxos saturados (AGS) e total de ?cidos graxos insaturados (AGI). Os animais F1 Sindi Nelore apresentaram menor concentra??o do ?cido graxo saturado mir?stico (0,88%), em compara??o ao Nelore (1,31%). N?o houve intera??o (P>0,05) entre grupo gen?tico e idade para os AGS estudados. O ?cido palm?tico foi o que apresentou maior concentra??o entre os AGS. Dentre os monoinsaturados houve diferen?a significativa (P<0,05) entre os grupos gen?ticos apenas para o ?cido palmitoleico, que teve 0,63 pontos percentuais a mais para os animais Nelore. O ?cido ol?ico foi o que apresentou maior concentra??o na carne dos dois grupos gen?ticos, com 41,44 % para os Nelore e 41,38 % para os F1 Sindi Nelore, seguido do ?cido linoleico, com 6,15 % para os Nelore e 4,86 % para os F1 Sindi Nelore. N?o houve diferen?a estat?stica (P>0,05) para total de monoinsaturados ou para o total de insaturados entre os grupos gen?ticos. N?o houve intera??o (P>0,05) entre grupo gen?tico e idade para os monoinsaturados e poliinsaturados. Houve diferen?a (P<0,05) para a rela??o &#969;6:&#969;3, sendo que F1 Sindi Nelore obtiveram menor rela??o &#969;6:&#969;3. A menor concentra??o de ?cido mir?stico e a menor rela??o &#969;6:&#969;3 na carne de bovinos F1 Sindi Nelore confere a esta ra?a uma carne mais saud?vel no que se refere ao perfil de ?cidos graxos.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-22T13:34:00Z No. of bitstreams: 1 2016 - Ronner Joaquim Mendon?a Brasil.pdf: 1892406 bytes, checksum: 2af27f8c4405579c52f8e3c5a83f0bce (MD5) / Made available in DSpace on 2017-05-22T13:34:00Z (GMT). No. of bitstreams: 1 2016 - Ronner Joaquim Mendon?a Brasil.pdf: 1892406 bytes, checksum: 2af27f8c4405579c52f8e3c5a83f0bce (MD5) Previous issue date: 2016-04-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Lysine is an essential amino acid used as a reference in diets based on the ideal protein concept. Determining the actual requirement for lysine is of great importance to formulate efficient feed without amino acids limitation or excesses. Three experiments were conducted in the Poultry Complex of Integrated Production Centre at Federal Rural University of Rio de Janeiro, objecting to estimate the digestible lysine requirements to broilers of low genetic potential for growth through the assessment of performance, carcass characteristics and breast meat quality. The first experiment corresponds to growth phase I (29-49 days), the second growth phase II (50-69 days) and the third final phase (70-84 days), where during each experiment was used different chickens. All experiments were conducted in a completely randomized design, with five treatments, four replications and twenty experimental units. The treatments were set with increasing lysine amounts obtained from the addition of L-Lysine HCl to the basal diet, replacing the ingredient corn starch as follows: 0.871, 1.011, 1.151, 1.291 and 1.431% in the growth phase I; 0.803, 0.943, 1.083, 1.223 and 1.363% in the growth phase II; and 0.766, 0.906, 1.046, 1.186% and 1.326% in the final phase. At the three stages studied, the lysine values nfluenced quadratically feed intake, weight gain and feed conversion. Lysine intake increased with enhanced amounts of lysine, however, it was detected a decrease in its usage efficiency. It was possible to measure the nutritional requirements for feed intake (1.298, 1.109, 1.150%), weight gain (1.183, 1.199, 1.162%) and feed conversion (1.203, 1.162, 1.126%), respectively for the growth phases I, II and final. The absolute weight as well as carcass and cuts yield were influenced by digestible lysine values of rations, where the highest carcass yield for growth phase I (73.62%) was estimated in the value of 1.162%, growth phase II (74.24%) in the value of 1.068%, and final phase (69.34%) in the value of 1.065% for digestible lysine. For chemical composition of breast meat, birds slaughtered at 70 days of age (growth phase II) was observed linear increase in moisture percentage and crude protein, and reduction the ether extract percentage. Nevertheless, it was not observed significant effect of broilers slaughtered at 85 days of age (final phase). For birds slaughtered at 70 and 85 days of age, the weight loss was significant by thawing and cooking the breast meat, increasing as improved lysine values. Therefore, optimizing feed conversion of Redbro Plum? broilers might be recommended, respectively, 1.203, 1.162, and 1.126% of lysine in the diet at phases 29 to 49, 50 to 69, and 70 to 84 days of age, corresponding to a proportion of digestible lysine:crude protein 6.09, 6.34, and 6.36%. / A lisina ? um amino?cido essencial utilizado como refer?ncia em ra??es formuladas com base no conceito de prote?na ideal. A determina??o da real exig?ncia de lisina ? de grande import?ncia na formula??o de ra??es eficientes, sem limita??es ou excessos de amino?cidos. Tr?s experimentos foram conduzidos no Setor de Avicultura do Centro de Produ??o Integrada da Universidade Federal Rural do Rio de Janeiro, com os objetivos de estimar as exig?ncias de lisina digest?vel para frangos de corte de menor potencial gen?tico para crescimento, atrav?s da avalia??o do desempenho, caracter?sticas de carca?a e de qualidade da carne do peito. O primeiro experimento corresponde a fase de crescimento I (29-49 dias), o segundo a fase de crescimento II (50-69 dias) e o terceiro a fase final (70-84 dias), sendo que em cada experimento foram utilizados frangos distintos. Todos os experimentos foram conduzidos em delineamento experimental inteiramente casualizado, com cinco tratamentos, quatro repeti??es e 20 unidades experimentais. Os tratamentos foram constitu?dos com valores crescentes de lisina digest?vel obtidos a partir da adi??o de L-Lisina HCl ? dieta basal, em substitui??o ao ingrediente amido de milho., sendo: 0,871; 1,011; 1,151; 1,291 e 1,431% na fase de crescimento I; 0,803; 0,943; 1,083; 1,223 e 1,363% na fase de crescimento II; e 0,766, 0,906; 1,046; 1,186% e 1,326% na fase final. Nas tr?s fases estudadas os valores de lisina digest?vel influenciaram de forma quadr?tica o consumo de ra??o, ganho de peso e convers?o alimentar. O consumo de lisina aumentou com os valores crescentes de lisina digest?vel, no entanto foi verificado uma redu??o na efici?ncia de utiliza??o de lisina. Foi poss?vel a estimativa das exig?ncias nutricionais para o consumo de ra??o (1,298; 1,109; 1,150%), ganho de peso (1,183; 1,199; 1,162%) e convers?o alimentar (1,203; 1,162; 1,126%), respectivamente para as fases de crescimento I, II e final. Os pesos absolutos e rendimentos de carca?a e cortes foram influenciados pelos valores de lisina digest?vel das ra??es, sendo que na fase de crescimento I o maior rendimento de carca?a (73,62%) foi estimado no valor de 1,162%, na fase de crescimento II (74,24%) no valor de 1,068%, e na fase final (69,34%) no valor de 1,065% de lisina digest?vel. Para composi??o qu?mica da carne do peito, nos frangos abatidos aos 70 dias de idade (fase de crescimento II) foi verificado efeito linear crescente no porcentual de umidade e prote?na bruta, e decrescente no porcentual de extrato et?reo. J? nos frangos abatidos aos 85 dias de idade (fase final), n?o foi constatado efeito significativo. Nos frangos abatidos aos 70 e 85 dias de idade, as perdas de peso por descongelamento e cozimento na carne do peito foram significativas, aumentando a medida que aumentou os valores de lisina digest?vel. Para otimiza??o da convers?o alimentar de frangos de corte Redbro Plum? podem ser recomendados, respectivamente, 1,203, 1,162 e 1,126% de lisina digest?vel na dieta nas fases de 29 a 49, 50 a 69 e 70 a 84 dias de idade, correspondendo a uma rela??o lisina digest?vel:prote?na bruta de 6,09; 6,34 e 6,36%.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

The goal of this study was to investigate feedlot performance and meat quality of calves born to cows that underwent a nutrient restriction during the second trimester of gestation which may be occurring in the Intermountain West. Thirty-four angus influenced calves from the same sire were used for this study. The calves were born from cows that were separated into either a maintenance group, and kept on an irrigated pasture, or a restricted group, that was placed on an unirrigated pasture and allowed to lose one body condition score during the second trimester of pregnancy. This study begins with the calves on day 85 of the finishing portion of the feedlot phase. During the finishing feedlot phase, calves were individually housed, fed ad libitum, and feedlot performance measurements were taken every 28 days. Carcasses from the calves were evaluated for yield and quality. A loin from each carcass was collected, aged, frozen, and cut into individually packaged steaks that were used to assess meat quality. There was no difference in feedlot performance and carcass measurements for either maintenance and restricted calves. Meat quality measurements revealed no difference in color, instrumental tenderness values, or composition of steaks from either group. A trained sensory panel found that ten characteristics of flavor were similar for both treatments. There was however, a trend for steaks from nutrient restricted cattle to have more of a bloody/serumy flavor. The trained sensory panel also found that there was a difference in tenderness of steaks from nutrient restricted animals being perceived as more tender than animals from maintenance cows. The results of this study demonstrate that nutrient restriction during mid-gestation does not have negative effects on feedlot performance, carcass characteristics, or meat quality measurements. These results also indicate that steaks from calves born to nutrient restricted cows may be perceived as more tender.

A preliminary trial to determine the effect of repeated freezing and thawing on beef striploins, showed that the effect of thawing on frozen non-aged beef significantly improved tenderness, flavour and acceptability, indicating that thawing had a similar effect to aging. In the subsequent study, 207 beef striploins were collected from the Southern Crossbreeding Project (SXB: 70 heifers grainfed for 80 days, 70 steers grainfed for 180 days), Davies Gene Mapping Project (DGM: 30 steers grainfed for 180 days) and also 37 Hanwoo striploins imported into Australia from Korea. SXB animals consisted of Hereford cross calves sired by Belgian Blue, Limousin, South Devon, Hereford, Angus, Wagyu and Jersey bulls. DGM animals consisted of purebred Limousins and Jerseys and Limousin by Jersey crosses. Sensory analysis of beef striploins involved semi-trained taste panel assessments, using nine-point category scales for initial and sustained juiciness, beef flavour, beef fat flavour, oily flavour, buttery flavour, chicken-skin flavour, corn flavour, grassy flavour and overall acceptability. Flavour acceptability was positively enhanced by increased levels of intramuscular fat (IMF%). Significant differences in breed were apparent for juiciness, beef flavour, buttery flavour and flavour acceptability, after adjusting data to a constant level of intramuscular fat, suggesting that some variation in flavour may be genetic. The Korean Hanwoo displayed a numerically higher intensity of chicken score and lower intensity of beef flavour. Australian cattle breeds differed in fatty acid composition between each other and also to that of the Korean Hanwoo. The latter had 57% mono-unsaturated fatty acids, which was significantly higher (P<0.001) than the Australian breeds (47%). Since IMF% was confounded with breed, breed differences were not significant when adjusted for IMF%. Jersey animals most closely resembled the Hanwoo in fatty acid profile, whilst animals containing Limousin differed markedly from the Hanwoo. A chemical sensor was able to establish significant differences between Korean Hanwoo and Australian animals and predominantly mirrored differences in fatty acid composition and to some extent flavour. Development of prediction equations from individual fatty acids was disappointing (R2< 15%). However, when fatty acid data, IMF% and chemical sensor data were combined to form prediction equations, moderate R2 values were obtained of (24% to 43%). / Thesis (M.Ag.Sc.)--School of Agriculture & Wine, 2001.