No description available.

No description available.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 96-109). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 96-109). Also available on the Internet.

Submitted by LUIZ GUSTAVO TEODORO DA SILVA null (teodoromedvet@hotmail.com) on 2017-12-14T01:14:19Z No. of bitstreams: 1 Dissertação Mestrado Luiz Gustavo 5 (Ficha Catalografica) ok.pdf: 726837 bytes, checksum: 8a8d8555c33479c7edbecb0313f13324 (MD5) / Submitted by LUIZ GUSTAVO TEODORO DA SILVA null (teodoromedvet@hotmail.com) on 2017-12-14T11:25:03Z No. of bitstreams: 1 Dissertação Mestrado Luiz Gustavo 5 (Ficha Catalografica) ok.pdf: 726837 bytes, checksum: 8a8d8555c33479c7edbecb0313f13324 (MD5) / Submitted by LUIZ GUSTAVO TEODORO DA SILVA null (teodoromedvet@hotmail.com) on 2017-12-14T13:50:31Z No. of bitstreams: 1 Dissertação Mestrado Luiz Gustavo 5 (Ficha Catalografica) ok.pdf: 726837 bytes, checksum: 8a8d8555c33479c7edbecb0313f13324 (MD5) / Approved for entry into archive by Luciana Pizzani null (luciana@btu.unesp.br) on 2017-12-14T17:34:15Z (GMT) No. of bitstreams: 1 silva_lgt_me_bot.pdf: 726837 bytes, checksum: 8a8d8555c33479c7edbecb0313f13324 (MD5) / Made available in DSpace on 2017-12-14T17:34:15Z (GMT). No. of bitstreams: 1 silva_lgt_me_bot.pdf: 726837 bytes, checksum: 8a8d8555c33479c7edbecb0313f13324 (MD5) Previous issue date: 2017-11-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Esse estudo avaliou o desempenho e saúde de novilhos de corte suplementados com produtos derivados de levedura (Celmanax; Church & Dwight Co., Inc.; Princeton, NJ), onde foi dividido em fase de pré-condicionamento (dia 4 ao 30) e fase de entrada no confinamento (dia 31 ao 69). Oitenta e quatro novilhos Agus x Hereford foram desmamados aproximadamente aos 6 meses de idade no dia 0 (peso corporal [PC] = 245 ± 2 kg; idade = 186 ± 2 dias), e mantidos em um único grupo do dia 0 ao 3. No dia 4 os novilhos foram alocados de acordo com peso á desmama e idade, em 21 baias no confinamento (4 bezerros por baia). As baias foram aleatoriamente designadas para receber: 1) não suplementação com Celmanax durante o estudo (n = 7 baias), 2) suplementação com Celmanax (14 g/dia/novilho; como alimento) do dia 14 ao 69 (n = 7 baias), ou 3) suplementação com Celmanax (14 g/dia/novilho; como alimento) do dia 31 ao 69 (n = 7 baias). Os novilhos tiveram livre acesso a feno de alfafa e receberam concentrado com base de milho que iniciou no dia 14. O Celmanax foi misturado diariamente com o concentrado. No dia 30, os novilhos foram transportados por 1.500 km (24 h). No dia 31, os novilhos retornaram para suas respectivas baias, permanecendo por 38 dias na fase de entrada no confinamento. O peso em jejum foi registrado no dia 4, 31 e 70. A ingestão de matéria seca (IMS) foi avaliada por baia diariamente (dia 14 ao 69). Os sintomas de doença respiratória bovina (DRB) foram observados diariamente (dia 4 ao 69) nos novilhos. Amostras de sangue foram coletadas no dia 14, 30, 31, 35, 40, 45, 54 e 69 para análise de concentrações cortisol, haptoglobina, fator de crescimento insulina tipo1 (IGF-1) e ácidos graxos não-esterificados (AGNE). Os resultados da fase de pré-condicionamento foram analisados comparando as baias que receberam Celmanax (CELM) ou não (CONPC) durante esta fase. Os resultados da fase de entrada no confinamento compararam as baias que receberam Celmanax do dia 14 ao 69 (CELPREC), do dia 31 ao 69 (CELRECV), ou sem suplementação com Celmanax (CON). O índice de DRB em novilhos foi baixo (P = 0.03) no grupo CELM comparado com grupo CONPC, enquanto que o GMD tendeu a ser maior (P = 0.07) em novilhos CELPREC e CELRECV vs. CON. Não foram detectadas diferenças entre os tratamentos (P ≥ 0.29) em IMS na fase de entrada no confinamento; entretanto G:I (eficiência alimentar) também tenderam (P = 0.08) a ser maior em novilhos CELPREC e CELRECV vs. CON. Não foram detectadas diferenças em outros tratamentos (P ≥ 0.20). Em resumo, a suplementação com Celmanax reduziu a incidência de DRB durante os 30-d de pré-condicionamento. Além disso, a suplementação com Celmanax tende a melhorar o ganho médio diário (GMD) e eficiência alimentar durante os 38 dias de entrada no confinamento, independentemente se a suplementação começou durante o pré-condicionamento ou até a entrada no confinamento. Esses resultados sugerem que a suplementação com Celmanax pode trazer benefícios a saúde na fase de pré-condicionamento e desempenho na fase de entrada no confinamento em bovinos de corte. / This experiment evaluated the impacts of supplementing a 794 yeast - derived product (Celmanax; Church & Dwight Co., Inc.; Princeton, NJ, USA) on 795 productive and health responses of beef steers, and was divided into a preconditioning 796 (day 4 to 30) and feedlot receivin g phase (day 31 to 69). Eighty - four Angus × Hereford 797 steers were weaned on day 0 (BW = 245 ± 2 kg; age = 186 ± 2 days), and maintained in 798 a single group from day 0 to 3. On day 4, steers were allocated according to weaning 799 BW and age t o a 21 - pen drylot (4 steers/pen). Pens were randomly assigned to (n = 7 800 pens/treatment): 1) no Celmanax supplementation during the study, 2) Celmanax 801 supplementation (14 g/steer daily; as - fed) from day 14 to 69, or 3) C elmanax 802 supplementation (14 g/steer daily; as - fed) from day 31 to 69. Steers had free - choice 803 access to grass - alfalfa hay, and were also offered a corn - based concentrate beginning on 804 day 14. Celmanax was mixed daily with the concentra te. On day 30, steers were road - 805 transported for 1500 km (24 h). On day 31, steers returned to their original pens for the 806 38 - day feedlot receiving. Shrunk BW was recorded on days 4, 31, and 70. Feed intake 807 was evaluated daily (day 14 t o 69). Steers were observed daily (day 4 to 69) for bovine 808 respiratory disease (BRD) signs. Blood samples were collected on days 14, 30, 31, 33, 809 35, 40, 45, 54, and 69, and analyzed for plasma cortisol, haptoglobin, IGF - I, and serum 810 fatty acids. Preconditioning results were analyzed by comparing pens that received 811 (CELM) or not (CONPC) Celmanax during the preconditioning phase. Feedlot 812 receiving results were analyzed by comparing pens that received Celman ax from day 14 813 to 69 (CELPREC), day 31 to 69 (CELRECV), or no Celmanax supplementation (CON). 814 During preconditioning, BRD incidence was less (P = 0.03) in CELM vs. CONPC. 815 During feedlot receiving, ADG (P = 0.07) and feed efficiency (P = 0.08) tended to be 816 greater in CELPREC and CELRECV vs. CON, whereas DM intake was similar (P ≥ 817 0.29) among treatments. No other treatment effects were detected (P ≥ 0.20). 818 Collectively, Celmanax supplementation red uced BRD incidence during the 30 - day 819 preconditioning. Moreover, supplementing Celmanax tended to improve ADG and feed 820 efficiency during the 38 - day feedlot receiving, independently of whether 821 supplementation b egan during preconditioning or after feedlot entry. These results 28 822 suggest that Celmanax supplementation benefits preconditioning health and feedlot 823 receiving performance in beef cattle. / 33004064048P2

Orientador: Mário De Beni Arrigoni / Resumo: Objetivando estudar o efeito da somatotropina bovina recombinante (rbST) sobre o desempenho, características de carcaça e concentrações plasmáticas de IGF-I e hormônios tireoideanos, trinta e seis bezerros mestiços ½ Angus-Nelore, com idade inicial de 63 ± 17 dias e pesando 76,8 ± 14,7 kg, criados em pastagens de Brachiaria decumbens e suplementados em creep feeding, foram submetidos a dois tratamentos até a desmama (217 dias) sendo que dezoito bezerros receberam 1,4 mg/kg de rbST (Boostin®) a cada 14 dias e dezoito bezerros controle receberam solução salina. As pesagens e colheitas de sangue foram realizadas a cada 28 dias e, à desmama, foram abatidos cinco animais de cada tratamento para avaliação das características de carcaça. Os animais suplementados apresentaram maior ganho de peso médio diário e peso vivo final, maiores concentrações plasmáticas de IGF-I e T4 em relação ao controle. Os parâmetros peso de carcaça quente, rendimento de carcaça, pesos de traseiro e dianteiro, gordura peri-renal, peso de fígado, área de olho de lombo, espessura de gordura subcutânea, pesos dos músculos do quarto do traseiro e concentração plasmática de T3 não diferiram significativamente entre os tratamentos. A utilização de rbST propiciou aumento de 7,9% no ganho de peso vivo e alterou o perfil hormonal de bezerros suplementados em creep feeding durante a fase de cria, não refletindo, entretanto, em maior peso ou rendimento de carcaça. / Abstract: The objective of this study was to evaluate the recombinant bovine somatotropin (rbST) effect on performance, carcass characteristics and plasma concentrations of IGF-I and thyroid hormones. Thirty-six ½ Angus-Nellore crossbred bull calves, 63 ± 17 days old and weighting 76.8 ± 14.7 kg, raised in Brachiaria decumbens pastures and creep fed, were assigned to one of two treatments until weaning (217 days): eighteen calves received 1.4 mg/kg of rbST (Boostin®) every 14 days and eighteen control calves received saline solution. Calves were weighed and blood samples were collected every 28 days and, at weaning, five animals from each treatment were slaughtered for carcass evaluation. The rbST-treated calves had greater average daily gain and final weight and higher IGF-I and T4 plasma concentrations than the control ones. The weights of hot carcass, forequarter and hindquarter, dressing percentage, kidney and pelvic fat, rib eye area, backfat thickness, weight of the hindquarter muscles and plasma concentrations of T3 were not affected by rbST. The rbST treatment implied in greater rates of gain, 7.9%, and altered the hormonal status in pre-weaning creep-fed bull calves, but did not reflect in greater carcass weight or dressing percentage. / Doutor

Resumo: Várias características são avaliadas por meio de escores visuais nos programas de avaliação genética no Brasil. Os sistemas de atribuição dos escores variam quanto ao número de classes de notas, ao referencial adotado para atribuição das notas e à frequência das notas nas diferentes classes e ao modelo empregado na análise dos dados. O objetivo neste estudo foi avaliar o impacto de diferentes escalas de atribuição dos escores, modelos de análise dos dados e sua interação na identificação dos genótipos superiores para essas características, por meio de dados simulados. Foram simulados dados de uma característica contínua na escala subjacente, transformados em valores (1 a 6) na escala discreta observada, com diferentes escalas (relativa uniforme, relativa normal, relativa assimétrica e fixa), dois valores de herdabilidade (0,25 e 0,49) e duas variâncias de grupos de contemporâneos (0,25 e 1,00). Estimaram-se os valores genéticos utilizando modelos de limiar, linear e linear após transformação dos dados. Análises com modelo de limiar e notas com escala relativa normal apresentaram melhores acurácias para a predição dos valores genéticos. A utilização do modelo de limiar incrementa a acurácia das estimativas, mas em razão da demanda computacional e de problemas de implementação, o modelo linear pode ser empregado na análise de dados categóricos avaliados sob escala relativa normal com seis classes. A transformação de dados proposta foi eficiente em algumas situações, podendo ser considerada como alternativa ao modelo linear, dependendo da estrutura dos dados / Abstract: Genetic improvement programs in Brazil involve the monitoring of many traits that are evaluated by means of visual scores. The systems used to evaluate animals vary in terms of the number of classes, the referential from which the scores are given, the distribution of observations in score classes and the model used to analyze the data. The objective of this study was to evaluate the impact of different scales of score evaluation, models of analysis and their interactions on the identification of superior genotypes for visual scores, by means of a simulation study. Data of a continuous trait were simulated in a subjacent scale and then transformed into a discrete trait (1 to 6) in the observable scale, with different scale distributions (uniform relative, normal relative, asymmetric relative and fixed), two heritabilities (0.25 and 0.49) and two contemporary group variances (0.25 and 1.00). Breeding values were estimated using threshold model, linear model and linear model after data transformation. The threshold model and the relative normal scale showed better accuracy for the prediction of breeding values. The use of a threshold model can lead to an increase in the estimates' accuracy, but despite the computational demand and implementation issues, the linear model can be used to analyze discrete data assigned under a normal relative scale with six score classes. The proposed data transformation was effective for some situations and depending on the data structure it should be considered as an alternative option instead of linear model / Orientador: Maurício Mello de Alencar / Coorientador: Roberto Augusto de Almeida Torres Junior / Banca: Gerson Barreto Mourão / Banca: Elias Nunes Martins / Banca: Danísio Prado Munari / Banca: Henrique Nunes de Oliveira / Doutor

Submitted by Karoline Silva Paulussi (karolpaulussi@hotmail.com) on 2018-08-02T20:32:52Z No. of bitstreams: 2 Dissertação de Mestrado Corrigido Isabel.pdf: 9768552 bytes, checksum: 43bef2d7889cb966d1ce1bc1abf03dcd (MD5) Dissertação de Mestrado Corrigido Isabel.pdf: 9768552 bytes, checksum: 43bef2d7889cb966d1ce1bc1abf03dcd (MD5) / Approved for entry into archive by Ederson Vasconcelos Pereira null (edersonpereira@fmva.unesp.br) on 2018-08-02T21:00:33Z (GMT) No. of bitstreams: 1 paulussi_ks_me_araca_int.pdf: 9768552 bytes, checksum: 43bef2d7889cb966d1ce1bc1abf03dcd (MD5) / Made available in DSpace on 2018-08-02T21:00:33Z (GMT). No. of bitstreams: 1 paulussi_ks_me_araca_int.pdf: 9768552 bytes, checksum: 43bef2d7889cb966d1ce1bc1abf03dcd (MD5) Previous issue date: 2018-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os animais congênicos possuem apenas uma região específica do cromossomo transferida de uma linhagem para outra através de cruzamentos monitorados por análises genéticas. Essa metodologia foi utilizada para produzir linhagem congênica de bovinos da raça Nelore carreando o polimorfismo no gene da miostatina proveniente do Belgian Blue. O objetivo desse trabalho foi comparar o peso ao nascimento, incidência de partos distócicos e taxa de mortalidade neonatal em animais de 3 variações genéticas para o gene da miostatina (homozigotos sem o polimorfismo, heterozigotos e homozigotos mutados). Animais homozigotos sem a mutação nasceram com 31,19 kg ± 0,32 kg, os heterozigotos com 35,82 kg ± 0,32 kg (diferença de 4,63 kg) e os homozigotos mutados nasceram com 40,46 ± 0,32 kg, com acréscimo médio de 9,26 kg acima dos bezerros homozigotos não mutados (p=2 x 10-16). Além disso bezerros machos apresentaram um acréscimo de 1,55 Kg em relação as fêmeas. A taxa de distocia dos bezerros homozigotos sem o polimorfismo e dos heterozigotos foram de 5,4% e 5,7%. A taxa de mortalidade dos bezerros homozigotos sem o polimorfismo e dos heterozigotos foram de 5,4% e 5,2%, dentro das normalidades esperadas. Entretanto, animais homozigotos mutados apresentaram altas taxas de distocia 47,5% e de mortalidade de bezerros 37,3%. Os dados indicam que a mutação no gene da miostatina quando em heterozigose gera um aumento de peso ao nascimento sem causar aumento de distocia ou de mortalidade neonatal. Concluímos que heterozigotos podem ser produzidos em larga escala, podendo ser uma estratégia vantajosa para aumentar a produtividade da pecuária de corte. / Congenic animals have only one chromosome specific region transferred from one lineage to another through crosses monitored by genetic analysis. This methodology was used to produce a Nellore cattle congenic line carrying the myostatin gene polymorphism from Belgian Blue. The objective of this study was to compare birth weight, incidence of dystocy and neonatal mortality rate in animals from the 3 genetic variations for the myostatin gene (homozygotes without the polymorphism, heterozygotes and mutated homozygotes). Homozygous animals without the mutation were born with 31,19 ± 0,32 kg, heterozygotes werte born with 35,82 ± 0,32 kg, a difference of 4,63 kg and the mutated homozygotes were born with 40,46 ± 0,319 kg, with an increase of 9,26 kg above homozygotes without the polymorphism calves (p = 2*10-16). In addition, male calves showed an increase of 1,55 kg in relation to females. The rates of dystocia of calves homozygous within polymorphism and heterozygotes were 5,4% e 5,7%. The rates of mortality of calves homozygous within polymorphism and heterozygotes were 5,4% e 5,2%, within expected normalities. However, mutated homozygous animals had high rates of dystocia (47.5%) and calves mortality (37.3%). The data indicate that mutation in the myostatin gene when in heterozygosis results in an increase birth weight without causing increased dystocia or neonatal mortality. We conclude that animals heterozygotes can be produced on a large scale, and may be an advantageous strategy to increase the productivity of beef cattle.

The main objective of the study was to determine the effect of farm to abattoir environmental conditions and their subsequent effects on behavioural and physiological responses, as well as the quality of meat from Nguni (NG) and non-descript (ND) beef steers reared extensively on natural pastures. The forty 16 – 19 months old steers (20 ND and 20 NG) used in the current study were grouped together, medically treated, allowed three weeks acclimatizing period and were used in this trial over a four-month period. The weather and periodical variations influence on time budgets and body weights of these steers were determined. Furthermore, the effects of on-farm successive handling on behavioural scores and physiological responses of the same steers were determined. Later in the trial, some pre-slaughter effects on response-behaviour, bleed-out times and selected blood physiological responses were determined. Finally, the effect of genotype, muscle type, lairage duration, slaughter order and stress responsiveness on pH24, temperature, colour (L*, a*, b*, C, HA), thawing (TL) and cooking (CL) losses and Warner Bratzler Shear Force (WBSF) of the meat harvested from the same steers were determined. The daily time budgets of steers in natural pastures changed with temperature, humidity, observation week and time of the day. The grazing behaviour was observed throughout the observation days (> 37 percent); though it was reduced (26.9±2.64 percent) on days with higher temperatures and low humidity. Higher proportions of drinking (1.5±1.04 percent) and standing (20.8±4.63 percent) behaviours prolonged in such weather conditions, which were mostly during midday. The avoidance-related behaviour of the steers during handling varies, with the steers showing more avoidance and aggression in other weeks than some. These variations could however be traced back to the events of that particular day/time of handling. Only Weighing Box (WBS) and stepping (SS) scores differed (P<0.05) with genotype; with more calm NG steers (> 40 percent) and not kicking than the ND steers that were more vocal (20–60 percent) and kicking (> 5 percent). In addition, the weekly behavioural responses were reflected (P<0.05) in the measured cortisol, glucose and lactate. However, regardless of the prominent negative behaviour seen over time, the levels of the measured blood constituents continued to drop. Furthermore, steers of different genotypes displayed similar (P>0.05) response to the identical pre-slaughter conditions they were exposed to. However, steers that were Transport Group 1 (TG1) showed more avoidance (63.2 percent) pre-slaughter than those in TG2 (23.9 percent). Furthermore, all the steers that were in slaughter Group 2 (SG2) showed less avoidance behaviour than those in other groups. Vocalization was observed only for ND steers (5 percent), in TG1 and SG2. Some connections between the observed pre-slaughter activities and some behavioural and physiological changes of these steers were established; with TG1 and SG1 steers showing higher cortisol (140±14.50 and 175.9±17.24 nmol/L, respectively) and lactate (12.4±0.83 and 13.5±1.12 mmolL) levels than the other groups. Lastly, the muscle type, genotype, lairage duration, slaughter order and stress responsiveness have an effect on some meat quality characteristics of the two genotypes; with the L. dorsi muscle having highest WBSF (38.0±1.35N) than the Superficial pectoral muscle (Brisket muscle) (30.7±1.35N). Additionally, steers lairaged for a shorter time produced a L. dorsi with higher WBSF (41.6±2.34N) and a Brisket with lower TL (2.7±0.24 percent). It can therefore be concluded that the conditions and activities at the farm, during transportation, lairaging and slaughter at the abattoir have an influence on some behavioural and physiological changes and the quality of beef harvested from the Nguni and non-descript steers that were extensively-reared in natural pastures. However, the relationship patterns between these different conditions are not clear.