Made available in DSpace on 2016-04-28T14:59:43Z (GMT). No. of bitstreams: 1 2007-Kely Cristina Bastos Teixeira Ramos.pdf: 271950 bytes, checksum: 614e6c37ea26196b362bfddfc370f7a2 (MD5) Previous issue date: 2007-08-24 / The objective of this study was to evaluate the effects of the different quantitative feed restriction programs on the productive performance, carcass characteristics, chemical composition of noble cuts and economic viability. Two hundred and sixty four male broiler chickens from the Cobb Avian 48 commercial strain were used. The performance essay took place from 8th to 42th day of age. The birds were distributed in six treatments with four replicates and ten birds per experimental unit. The experimental design was the completely randomized. The feed restriction programs were: T1 ad libitum; T2- feed restriction at 8th day of age; T3- feed restriction at 8th and 13th days of age; T4- feed restriction at 8th, 13th and 18th days of age; T5- feed restriction at 8th, 13th, 18th and 23th days of age; T6- feed restriction at 8th, 13th, 18th, 23th and 28th days of age. Each feed restriction consisted in the withdrawal of the feed for 24 hours. In the end of performance test, two broilers per experimental unit with group representative average weight totalizing forty eight animals were taken to the evaluation of yield, carcass characteristics and chemical composition of noble cuts. Evaluating the total period from 8-42 days of age, the feed restriction program did not influence the feed intake, feed:gain ratio and weight gain of analyzed birds. To the carcass characteristics, was observed that absolute weight and the carcass, thigh, upper thigh and back yields were not influenced by the studied feed restriction programs such as the relative weights of heart, liver, gizzard and intestine. Nevertheless, breast weight was negatively influenced by the severe restriction programs (T4, T5 and T6). The relative weight of abdominal was superior in the carcasses of T6 in relation to the T1. Thigh and upper thigh crude protein an ether extract contents were influenced by the feed restriction, but without a defined tendency. About the economical indicators, the broilers that were not submitted to the restriction (T1) presented greater average gross income (AGI) and relative profitability index (RPI) while the treatment submitted to the more intense restriction (T6) resulted in worst AGI and RPI values. Considering the results of carcass characteristics and economical indicators parameters presented in this study, no reasons were found to justify the adoption of feed restriction programs in male broiler chickens from Cobb strain. / O objetivo deste estudo foi avaliar os efeitos dos diferentes programas de restri??o alimentar quantitativa no desempenho produtivo, caracter?sticas da carca?a, composi??o qu?mica dos corte nobres e viabilidade econ?mica. Foram utilizados duzentos e sessenta e quatro frangos de corte machos da linhagem comercial Cobb Avian 48. O ensaio de desempenho ocorreu do 8? ao 42? dia de idade. As aves foram distribu?das aleatoriamente em seis tratamentos com quatro repeti??es e dez aves por unidade experimental. O delineamento experimental utilizado foi o inteiramente casualizado. Os programas de restri??o alimentar foram: T1 ra??o ? vontade; T2 restri??o alimentar no 8? dia de idade; T3 restri??o alimentar no 8? e 13? dias de idade; T4 restri??o alimentar no 8? 13? e 18? dias de idade; T5 restri??o alimentar no 8?, 13?, 18? e 23? dias de idade; T6 restri??o alimentar no 8?, 13?, 18?, 23? e 28? dias de idade. Cada restri??o alimentar consistiu na retirada total da ra??o por 24 horas. Ao final do ensaio de desempenho, foram retirados dois frangos por unidade experimental com peso m?dio representativo do grupo, totalizando 48 animais, para avalia??o das caracter?sticas da carca?a e composi??o qu?mica dos cortes nobres. Avaliando o per?odo total de 8-42 dias de idade os programas de restri??o alimentar n?o influenciaram o consumo de ra??o, a convers?o alimentar e o ganho de peso das aves analisadas. Quanto ?s caracter?sticas de carca?a, observou-se que os pesos absolutos e os rendimentos da carca?a, coxa, sobrecoxa e dorso n?o foram influenciados pelos programas de restri??o alimentar estudados, assim como os pesos relativos do cora??o, f?gado, moela e intestinos. No entanto, o peso do peito foi influenciado negativamente pelos programas de restri??o mais severos (T4, T5 e T6). O peso relativo da gordura abdominal foi superior nas carca?as do T6 em rela??o ao T1. Os teores de prote?na bruta e extrato et?reo da coxa e da sobrecoxa foram influenciados pela restri??o alimentar, mas sem uma tend?ncia definida. Em rela??o aos indicadores econ?micos, os frangos que n?o foram submetidos ? restri??o (T1) apresentaram maior renda bruta m?dia (RBM) e ?ndice relativo de rentabilidade (IRR), enquanto que o tratamento submetido ? restri??o mais severa (T6) resultou em piores valores para RBM e IRR. Considerando-se os resultados para os par?metros de caracter?sticas de carca?a e indicadores econ?micos apresentados no presente estudo, n?o foram encontradas raz?es que justifiquem a ado??o de programas de restri??o alimentar em frangos de corte machos da linhagem Cobb.

Made available in DSpace on 2014-12-17T15:36:50Z (GMT). No. of bitstreams: 1 AlexsandroLDO.pdf: 329212 bytes, checksum: 72e9f94d5f2af1bff3f6180d3b9b5aa7 (MD5) Previous issue date: 2007-09-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Timeplace learning is the capacity of organisms to associate both space and time with a biological relevant stimulus such as food. Experiments are usually done with food restricted animals due to the belief that food system activation is necessary for timeplace learning. Another line of thought suggest that, in addition to food system activation, response cost should be increased to effectively allow timeplace discrimination. The purpose of this experiment was to test whether a complex environment, which presumably implied in a heightened response cost, would facilitate timeplace association in satiated rats using a highly palatable food as reward. Nine rats were trained in a timeplace task for 30 nonconsecutive days. A large experimental box (1x1m) divided in four compartments was used. To access each compartment the animal had to overcome a series of obstacles such as ramps, staircases and mazes. Two feeders localized in opposite compartments were rewarded with sunflower seeds in two daily sessions. One feeder offered the reward during the morning sessions while the second feeder in afternoon sessions. After the 15th day of training, the animals began to show a preference for the correct feeder during the correct time of day expressed by increased frequency of visits as well as lower latency to access the feeders. These results suggest that satiated animals are also capable of learning a timespace task as far as the experimental context is complex enough to result in a higher response cost / O aprendizado espacialtemporal ? a capacidade dos organismos em associar espa?o e tempo com um est?mulo biologicamente relevante, tal como a comida. Experimentos geralmente s?o feitos com animais em restri??o alimentar, devido acreditarse que a ativa??o do sistema alimentar ? necess?ria para a mem?ria espacialtemporal. Outra linha de pensamento sugere que, em conjunto com a ativa??o do sistema alimentar, o custo de resposta deve ser aumentado para efetivamente permitirse a discrimina??o espa?otempo. O prop?sito desta experi?ncia foi testar se um ambiente complexo, presumivelmente implicando num aumento do custo de resposta, poderia facilitar a associa??o espa?otempo em animais saciados, utilizando um alimento altamente palat?vel como recompensa. Nove ratos foram treinados em uma tarefa espacialtemporal por 30 dias n?oconsecutivos. Uma caixa experimental grande (1m x 1m x 0,5m) dividida em quatro compartimentos foi utilizada. Para acessar cada compartimento o animal tinha que vencer uma s?rie de obst?culos, tais como rampas, escadas e labirintos. Dois comedouros localizados em compartimentos opostos forneciam sementes de girassol como recompensa em duas sess?es di?rias. Um comedouro ofereceu recompensa durante as sess?es matutinas enquanto o segundo comedouro ofereceu recompensa durante as sess?es vespertinas. Depois do 15? dia de treino, os animais come?aram a demonstrar uma prefer?ncia pelo comedouro correto na hora correta do dia, expressa tanto pelo aumento na freq??ncia de visitas quanto na diminui??o da lat?ncia para acessar o comedouro correto. Estes resultados sugerem que animais saciados tamb?m s?o capazes de aprender uma tarefa espacialtemporal, desde que o contexto experimental seja complexo o bastante para resultar num custo de resposta mais alto