The effects of feeding with two high energy diets ( high carbohydrate and high lipid) and the feeding regime of the two diets on growth, feeding conversion rate, and body composition of the cobia were studied. Based on the observation of lipid redistribution under dietary regime change in rats, this study was aimed to understand how regime change affects the tissue lipid content in the cobia. The study had three parts: preliminary experiment, experiment I, and experiment II. The preliminary experiment was designed to find the proper time to switch the high energy diets and to see the adaptation of cobia to the highe energy dietary treatments. The experiment I was conducted to monitor the growth and body composition of cobia fed for thirty-two days with different experimental diets, including control diets, high carbohydrate diets (HC), high lipid diets (HL), and different feeding regimes (HC¡÷HL: feeding the HC diet for the first sixteen days and the HL diet for the subsequent sixteen days; HL¡÷HC: feeding the HL diet for the first sixteen days and the HC diet for the subsequent sixteen days. The experiment II was studied serum concentration of glucose, triacylglycerol, and free fatty acids and tissues triacylglycerol concentration in liver and white muscle. The fish fed with the HC diet had higher body weight and lower feeding conversion rate than the HL group in first sixteen days; however, the growth of the two groups was not significantly different during the thirty-two day period. The lipid content of dorsal muscle was significantly higher in HC¡÷HL than that in HL¡÷HC; wherease, the lipid content of ventral muscle and viscera was not signficantly affected. The concentrations of serum triacylglycerol, free fatty acid, and relative mean ratio of triacylglycerol in muscle to triacylglycerol in liver were significantly affected. The results of relative mean ratio of serum TG to serum FFA and relative mean ratio of muscle TG to liver TG, suggest that high carbohydrate diet drives de nova lipid production in liver, which circulates to the peripheral tissues for storage as triacylglycerol. High lipid diet preferentially offers energy for lipolysis to produce energy. These results are consistant with the results in rats. Our results show that high energy diets provided a higher growth rate than the control diet, but there were no growth difference in cobia fed high carbohydrate diets, or high lipid diets, or between different feeding regimes. The cobia fed the high carbohydrate diet and the high lipid diet might use different ways for lipid accumulation. These fed the high carbohydrate diet had formed more triacylglycerol than that these fed high lipid diets. The feeding regime shift between the high carbohydrate diet and the high lipid diet significantly affect the the lipid content of the dorsal muscle in the cobia.

Made available in DSpace on 2015-03-26T13:54:54Z (GMT). No. of bitstreams: 1 texto completo.pdf: 395924 bytes, checksum: ff26f8d67dd02ecb3414b321f967734f (MD5) Previous issue date: 2009-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The productive section of meat should implement technologies that produce younger animals, with racial characteristics that promote quality meat. The manipulation of the diet and use of industrial crossing are technologies of easy access to the producer. Sixty cattle castrated with 18 moths of age, being 20 Nellore (NE), F1 Simmental x Nellore, F1 Angus x Nellore with average body weight of 265.6±6.4, 325.3±4.7 kg and 324.6±6.0 kg, respectively. The experiment was in completely randomized experimental design, in factorial 3 x 3, being 3 genetics groups (Nellore, F1 Simmental x Nellore, F1 Angus x Nellore) and 3 alimentary regimes (feeding to the maintenance level and ad libitum with 1% and 2% of the corporal weight (CW) at concentrated in natural matter of the diet), composing, therefore, 9 treatments, with 6 repetitions in each genetic group in the feeding levels ad libitum (1% and 2%) and four repetitions for the restricted feeding level (maintenance). After period of initial adaptation, the animals designated to received 2% of CW at concentrated one week passed receiving 1.5% CW in concentrated and one more week receiving 2% CW in concentrated for adaptation on the diet. The animals designated to receive 1% CW in concentrated and the treatment in maintenance started your diet immediately after the initial adaptation. At the end of that second week, call of second adaptation, all the animals were heavy, in fast of 16 hours, for beginning of the first experimental period. The animals in maintenance regime received the same diet supplied for the animals fed with 1% of CW at concentrated, in the equivalent amount to 1% of CW. The roughage was supplied at ease, being constituted of corn silage. The concentrate, in restricted amount, was formulated at base of ground corn, soybean meal, whole cottonseed, soybean hulls, urea/ammonium sulfate (9:1), sodium bicarbonate, magnesium oxide, common salt and mineral premix. The concentrate were formulated for that the same ration was offered the both treatments, changing only relationship corn/urea + ammonium sulfate allowing the diets to keep isonitrogenous (12.5% CP in the DM). The animals were maintained in individual stalls, with floor, concrete feeder and drinker, with total area of 30 m2, with 8 m2 of covered area. The experiment had total duration of 136 days, being 30 days of adaptation to the experimental conditions, 14 days of adaptation to the diet (2nd adaptation) and 84 days of experimental period. Were intermediate weighs, in fast of 16 hours, to the 28 and 56 days of performance. After the period of evaluation performance, started the slaughter of the animals. Like this, was evaluated the effect of genetic group and alimentary regime on quantitative and qualitative characteristics, physical and chemical composition of the gain, of the carcass and of the empty body and standard of deposition of tissues. Animals fed with larger concentrate level had larger (P<0.05) cold carcass weight (CCW), cold carcass dressing (CCD) and rib eye area/100 Kg of cold carcass (REA/100 kg) in relation to the small concentrate level. Except for cut of the top sirloin butt, there was not difference (P>0.05) in the feeding ad libitum for the yield of cuts. Crossbred animals presented larger (P <0.05) CCW that animals NE. The animals NA had larger (P<0.05) fat thickness (FT) and smaller REA/100 kg in relation to the animals NS. The trade cuts was not influenced (P>0.05) for the genetic group, except for the cut of the shoulder clod that had smaller (P<0.05) yield in the crossbred animals. The final pH was not influenced (P<0.05) for the treatments and it was inside of the appropriate patterns for export, below 6.0. The measures of REA and FT taken along the development of the animals detected the growth stage in that met. Crossbred animals and fed with larger concentrate level possess carcasses with more appropriate characteristics to the requirements of the import market, in a general way. Animals in maintenance presented larger (P<0.05) proportion of bones and muscle in the carcass and animals NE had larger muscle proportion and smaller (P<0.05) proportion of total fatty in the carcass that crossbreds animals. Animals NE and in maintenance present smaller (P<0.05) amount of total fat that crossbreds and fed ad libitum, respectively. The fat was deposited in larger proportion in the intermuscle fatty tissue, followed by the fatty of mesentery. The rate of deposition of tissues in the carcass was smaller in the animals NE and fed with 1% of concentrated (except for subcutaneous fatty tissue), in relation to the crossbreds animals and fed with 2% of concentrated, respectively. The rate of fat deposition in the adipose tissue of mesentery it was larger (P<0.05) in the animals NA and fed with 2% of concentrated in relation to NS and animals fed with 1% of concentrated respectively. Animals NS and NA presented more tender meat than the animals NE. The meat of animals fed with 1% and 2% of concentrated it lost more water (P<0.05) that the meat of the animals in maintenance during the thawing and in the total losses. During the cooking, there was difference (P<0.05) in the losses for drip loss for all the regimes, being the larger losses in that order: 1% of concentrated, 2% of concentrated and maintenance. The genetic group Nellore presented larger proportion of intermediate fibers (P<0.05) and lower proportion of oxidative fibers (P<0.05), the opposite was observed for the crossbred animals. There were difference (P<0.05), in the proportion of separated fibers in agreement with contractile characteristics, inside of genetic group. The animals Nellore had larger proportion of fibers of fast contraction and smaller proportion of fibers of slow contraction (P<0.05) in relation to the crossbred animals. Crossbred animals have more tender meat than the animals Nellore; however, all were inside of the pattern for the meat to be considered tender. Animals in restriction lost less water than animals fed ad libitum and the animals Nellore lost more water than the crossbred animals. / O setor produtivo de carne deve implementar tecnologias que produzam animais mais jovens, com características raciais que promovam carne de qualidade. A manipulação da dieta e o uso de cruzamento industrial são tecnologias de fácil acesso ao produtor. Foram utilizados 60 bovinos castrados de 18 meses, sendo 20 Nelore (NE), F1 Simental x Nelore , F1 Angus x Nelore com peso médio de 265,6±6,4 kg, 325,3±4,7 kg e 324,6±6,0 kg, respectivamente. O experimento foi em delineamento inteiramente casualizado, em esquema fatorial 3 x 3, sendo 3 grupos genéticos (Nelore, F1 Simental x Nelore, F1 Angus x Nelore) e três regimes alimentares (alimentação ao nível de mantença e ad libitum com 1% e 2% do peso corporal (PC) em concentrado na matéria natural da dieta),compondo, portanto, 9 tratamentos ( 6 repetições em cada grupo genético nos níveis de alimentação ad libitum (1% e 2%) e quatro repetições para o nível de alimentação restrito). Após período de adaptação inicial, os animais designados a receber 2% do PC em concentrado passaram uma semana recebendo 1,5% do PC em concentrado e mais uma semana recebendo 2% do PC em concentrado para adaptação à dieta. Os animais designados a receber 1% do PC em concentrado e o tratamento em mantença iniciaram sua dieta imediatamente após a adaptação inicial. Ao término dessa segunda semana, chamada de segunda adaptação, todos os animais foram pesados, em jejum de 16 horas, para início do primeiro período experimental. Os animais em regime de mantença receberam a mesma dieta fornecida para os animais alimentados com 1 % do PC em concentrado, na quantidade equivalente a 1 % do PC. O volumoso foi fornecido à vontade, sendo constituído de silagem de milho. O concentrado, em quantidade restrita, foi formulado à base de milho moído, farelo de soja, caroço de algodão, casca de soja, uréia/sulfato de amônio (9:1), bicarbonato de sódio, óxido de magnésio, sal comum e premix mineral. Os concentrados foram formulados para que a mesma ração fosse ofertada a ambos tratamentos, mudando apenas a relação milho/uréia+sulfato de amônia permitindo que as dietas se mantivessem isoprotéicas (12,5 % de PB na MS). Os animais foram mantidos em baias individuais, com piso, comedouro e bebedouro de concreto, com área total de 30 m2, dos quais 8 m2 de área coberta com telhas de amianto. O experimento teve duração total de 136 dias, sendo 30 dias de adaptação às condições experimentais, 14 dias de adaptação à dieta (2ª adaptação) e 84 dias de período experimental. Foram realizadas pesagens intermediárias, em jejum de 16 horas, aos 28 dias e 56 dias de desempenho. Após o período de avaliação do desempenho, iniciou-se o abate dos animais. Assim, avaliou-se o efeito de grupo genético e regime alimentar sobre características quantitativas, qualitativas, composição física e química do ganho, da carcaça e do corpo vazio e padrão de deposição de tecidos. Animais alimentados com maior nível de concentrado tiveram maior (P<0,05) peso de carcaça fria (PCF), rendimento de carcaça fria (RCF) e área de olho de lombo/100 Kg de carcaça fria (AOL/100 kg) em relação ao menor nível de concentrado. Exceto para o corte da alcatra, não houve diferença (P>0,05) na alimentação ad libitum para o rendimento de cortes. Animais cruzados apresentaram maior (P<0,05) PCF que animais NE. Os animais NA tiveram maior (P<0,05) espessura de gordura subcutânea (EGS) e menor AOL/100 kg em relação aos animais NS. O rendimento de cortes não foi influenciado (P>0,05) pelo grupo genético, exceto pelo corte da paleta que teve menor (P<0,05) rendimento nos animais cruzados. O pH final não foi influenciado (P<0,05) pelos tratamentos e ficou dentro dos padrões adequados para exportação, abaixo de 6,0. As medidas de AOL e EGS tomadas ao longo do desenvolvimento dos animais detectaram o estágio de crescimento em que eles se encontravam. Animais cruzados e alimentados com maior nível de concentrado possuem carcaças com características mais adequadas às exigências do mercado importador, de uma forma geral. Animais em mantença apresentaram maior (P<0,05) proporção de ossos e músculo na carcaça e animais NE tiveram maior proporção de músculo e menor (P<0,05) proporção de tecido adiposo total na carcaça que animais cruzados. Animais NE e em mantença apresentam menor (P<0,05) quantidade de gordura total que animais cruzados e alimentados ad libitum, respectivamente. A gordura foi depositada em maior proporção no tecido adiposo intermuscular, seguido do tecido adiposo de mesentério. A taxa de deposição de tecidos na carcaça foi menor nos animais NE e alimentados com 1% de concentrado (exceto para tecido adiposo subcutâneo), em relação aos animais cruzados e alimentados com 2% de concentrado, respectivamente. A taxa de deposição de gordura no tecido adiposo de mesentério foi maior (P<0,05) nos animais NA e alimentados com 2% de concentrado em relação aos NS e animais alimentados com 1% de concentrado, respectivamente. Animais NS e NA apresentaram carne mais macia que os animais NE. A carne de animais alimentados com 1% e 2% de concentrado perdeu mais água (P<0,05) que a carne dos animais em mantença durante o descongelamento e nas perdas totais. Durante a cocção, houve diferença (P<0,05) nas perdas por gotejamento para todos os regimes, sendo as perdas maiores nessa ordem: 1% de concentrado, 2% de concentrado e mantença. O grupo genético NE apresentou maior proporção de fibras intermediárias (P<0,05) e menor proporção de fibras oxidativas (P<0,05), o contrário foi observado para os animais cruzados. Houve diferença (P<0,05), na proporção de fibras separadas de acordo com características contráteis, dentro de grupo genético. Os animais NE tiveram maior proporção de fibras de contração rápida e menor proporção de fibras de contração lenta (P<0,05) em relação aos animais cruzados. Animais cruzados possuem carne mais macia que os animais NE; no entanto, todas estavam dentro do padrão para a carne ser considerada macia. Animais em restrição perderam menos água que animais alimentados ad libitum e os animais NE perderam mais água em relação aos animais cruzados.