Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-08-22T18:12:38Z No. of bitstreams: 1 2017 - Helio Jos? de Ara?jo Filho.pdf: 1260983 bytes, checksum: 99a5ebc69e0f2db8e73b43a3fbf3d09d (MD5) / Made available in DSpace on 2018-08-22T18:12:38Z (GMT). No. of bitstreams: 1 2017 - Helio Jos? de Ara?jo Filho.pdf: 1260983 bytes, checksum: 99a5ebc69e0f2db8e73b43a3fbf3d09d (MD5) Previous issue date: 2017-02-22 / FAPERJ / CNPq / The growth of the world population has increased the demand for food, this implies in reduction of the available areas for animal production, which makes imperative the development, evaluation and application of techniques that propitiate the increase of the productivity of Brazilian livestock. Thus, the objective of this study was to evaluate and compare the productive and economic performance of beef cattle finishing under three management and feeding systems, namely: at pasture with mineral supplementation (PSM); at pasture with protein-energy supplementation (SPE); And raised at feedlot with high concentrate diet (AG). For this purpose, 60 castrated male bovines, crossbreed Nelore x Angus, which were distributed in a design Completely randomized, with three systems and twenty animals in each. The study was conducted at Fazenda Tr?s Morros, in the city of Casimiro de Abreu. The means of the studied variables were estimated by LSMEANS and compared by PDIFF, at 5% of probability (p<0.05%), of SAS?. The feedlot (AG) presented shorter finishing time (76 days) and higher weight gain (102.2 kg), total daily average gain (1.35 kg.animal-1.day-1) and average daily gain of carcass (1.02 kg.animal-1.day-1), followed by SPE and PSM, respectively, in relation to the finishing time and the average daily gain of carcass. Regarding weight gain and average daily gain, there was no significant difference (p <0.05) between SPE and PSM. In turn, the average carcass weights (ACW), carcass yields (CY), and carcass gains (CG) of AG (ACW 298.3 kg or 19.9@, CY 55.1% and CG 78.3 kg) and SPE (ACW 288.2 kg or 19.2@, CY 56.1% and CG 68.1 kg) were similar to each other and higher (p<0.05) to PSM. The system PSM had the lowest production costs (effective operational cost R$ 2,277, total operational cost R$ 2,323 and total cost R$ 2,466), while the highest effective operational cost was AG (R$ 2,598) and the highest total operational cost (TOC) and total cost (TC) of SPE (TOC of R$ 2,632 and R$ 2,668). The highest gross margin (R$ 341.1) and net margin (R$ 295.9), net result (R$ 153.0), profitability (5.84%) and simple rentability (4.54%) were obtained by PSM, followed by SPE and AG, in that order. However, when the cash flows were corrected by the general price index - domestic availability (GPI-DA), the gross margins (R$ 199.6) and net margin (R$ 152.2) of PSM remained the highest and followed by SPE and AG (respectively), but the other economic indicators were the lowest among the systems. In this way, the highest net result (R$ 70.7), profitability (2.43%) and simple rentability (1.81%) were observed in SPE. Therefore, the feedlot provided the smallest production cycle and increased animal productivity, the pasture system with mineral supplementation allowed the reduction of production costs, while the concentrate supplementation presented better economic result during the dry season of the year 2015. According to the information obtained, both confinement and supplementation with whole maize diet have the potential to be strategic alternatives to the finishing cattle at exclusively pasture, provided satisfactory market conditions. / O crescimento da popula??o mundial tem elevado a demanda por alimento, isso implica em redu??o das ?reas dispon?veis para produ??o animal, o que torna imperativo o desenvolvimento, avalia??o e aplica??o de t?cnicas que propiciem o aumento da produtividade da pecu?ria brasileira. Desta forma, o objetivo deste estudo foi avaliar e comparar o desempenho produtivo e econ?mico da termina??o de bovinos sob tr?s sistemas de manejo e alimenta??o, a saber: a pasto com suplementa??o mineral (PSM); a pasto com suplementa??o prot?ico-energ?tica (SPE); e confinamento com fornecimento de dieta alto gr?o (AG). Para tanto, foram utilizados 60 bovinos machos castrados, ? sangue Nelore x Angus, distribu?dos em um delineamento inteiramente casualizado, em tr?s sistemas e vinte animais em cada. O estudo foi conduzido na Fazenda Tr?s Morros, no munic?pio de Casimiro de Abreu/RJ. As m?dias das vari?veis estudadas foram estimadas pelo LSMEANS e comparadas pela PDIFF, a 5% de probabilidade (p<0,05), do SAS?. O confinamento (AG) apresentou menor tempo de termina??o (76 dias) e maiores ganho de peso (102,2 kg), ganho m?dio di?rio total (1,35 kg.animal-1.dia-1) e ganho m?dio di?rio de carca?a (1,02 kg.animal-1dia-1), seguido por SPE e PSM, respectivamente, em rela??o ao tempo de termina??o e ao ganho m?dio di?rio de carca?a. No que se refere ao ganho de peso e ao ganho m?dio di?rio total, n?o houve diferen?a significativa (p<0,05) entre SPE e PSM. Por sua vez, os pesos m?dios de carca?a (PMC), os rendimentos de carca?a (RC) e os ganhos de carca?a (GC) de AG (PMC de 298,3 kg ou 19,9 @, RC de 55,1% e GC de 78,3 kg) e SPE (PMC de 288,2 kg ou 19,2 @, RC de 56,1% e GC de 68,1 kg) foram semelhantes entre si e superiores (p<0,05) a PSM. J? o sistema PSM obteve os menores custos de produ??o (custo operacional efetivo de R$ 2.277, custo operacional total de R$ 2.323 e custo total de R$ 2.466), enquanto o maior custo operacional efetivo foi de AG (R$ 2.598) e os maiores custo operacional total (COT) e custo total (CT), de SPE (COT de R$ 2.632 e CT R$ 2.668). As maiores margem bruta (R$ 341,1) e l?quida (R$ 295,9), resultado l?quido (R$ 153,0), lucratividade (5,84%) e rentabilidade simples (4,54%) foram obtidas por PSM, seguidas por SPE e AG, nesta ordem. Por?m, quando os fluxos de caixa foram corrigidos pelo ?ndice geral de pre?os ? disponibilidade interna (IGP-DI), as margens bruta (R$ 199,6) e l?quida (R$ 152,2) de PSM permaneceram as mais elevadas e acompanhadas por SPE e AG (respectivamente), contudo, os demais indicadores econ?micos foram os menores entre os sistemas. Desta forma, os maiores resultado (R$ 70,7), lucratividade (2,43%) e rentabilidade simples (1,81%) foram observados em SPE. Portanto, o confinamento proporcionou o menor ciclo de produ??o e maior produtividade animal, o sistema a pasto com suplementa??o mineral possibilitou a redu??o dos custos de produ??o, enquanto a suplementa??o com concentrado apresentou melhor resultado econ?mico, durante a esta??o seca do ano de 2015. De acordo com as informa??es obtidas, tanto o confinamento quanto a suplementa??o com dieta ? base de milho inteiro possuem potencial para serem alternativas estrat?gicas ? termina??o de bovinos exclusivamente a pasto, desde que presentes condi??es satisfat?rias do mercado.

Made available in DSpace on 2015-03-26T13:55:08Z (GMT). No. of bitstreams: 1 texto completo.pdf: 305006 bytes, checksum: fe7fd5485f44b6e8a7a8e434669ffc90 (MD5) Previous issue date: 2006-03-20 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this trial was to evaluate the effects of different supplementation levels on performance, chemical composition and carcass characteristics of steers from different genetic groups of finishing steers grazing Brachiaria brizantha cv. Marandu pasture. Fifty-four steers averaging 20 months old were divided in three groups according to the initial body weight (criterion adopted by the farmers), as follows: 1) 23 steers averaging 325+25 kg and fed mineral salt (control), 2) 17 steers averaging 362+14 kg fed concentrate at 0.125% of body weight, and 3) 14 steers averaging 407+24 kg fed concentrate at 0.250% of body weight. The supplements contained corn, soybean meal, and starea formulated to yield 24% crude protein. Three ruminally fistulated steers averaging 20 months old and 420+25 kg were used for evaluation of dry matter intake and ruminal parameters. The animals of treatments 1, 2 and 3 intaked of 0.070, 0.490 and 1.100 kg/day; and averaged daily gain of 0.631, 1.099 and 1.161 kg/day, respectively. It was observed feed:gain ratio of 0.91:1 and 10:1 kg, respectively, at 0.125 and 0.250% BW levels. The increasing supplementation levels, during the finishing phase of grazing steers, provided higher values of weight gain at 0.250% BW levels, but with better feed:gain ratio at 0.125% BW level. No difference (P>0.05) on dry matter forage intake by increasing the levels of supplementation was observed. It was observed significant effect (P<0.05) of supplement x hour interaction on ammonia and pH values. The pH values for all treatments averaged 6.2, below which inhibit fiber digestion. The ruminal ammonia contents of the supplemented animals (0.125 and 0.250% BW) were always higher than the threshold value of 10 mg/dL that maximize microbial growth and ruminal digestibility in tropical conditions. Fourteen steers from different genetic groups (seven ½Nelore x ½Santa Gertrudis, four ½Nelore x ½Simental and three Nellore) averaging 481+30 kg of weight and 24 months old were slaughtered to evaluate chemical composition and carcass characteristics. No significant effects (P>0.05) among genetic group on slaughter weight, carcass weight, carcass yield, beef round weight, beef round yield, short ribs weight, beef plate weight, fat thickness, and loin eye area were observed. It was observed difference (P<0.05) for the percentages of humidity, ash, protein, total lipid and cholesterol among the genetic group. It was observed higher (P<0.05) linoleic acid content (CLA) on the Longissimus dorsi muscle of crossbred ½Nellore x ½Santa Gertrudis than ½Nellore x ½Simental and Nellore. The meat of grazing ½Nelore x ½Santa Gertrudis showed high nutritional quality than the other genetic groups. / O presente experimento avaliou o efeito de diferentes níveis de suplementação no desempenho de novilhos na fase de terminação em pastagens de braquiarão (Brachiaria brizantha cv. Marandu) e a composição quimíca e características de carcaça de novilhos de diferentes grupos genéticos terminados a pasto. Foram utilizados 54 novilhos com idade de 20 meses, divididos em três lotes de acordo com o peso vivo inicial (critério utilizado pelos proprietários da fazenda onde o experimento foi realizado). O primeiro lote continha 23 animais com peso vivo inicial de 325+25 kg que receberam apenas sal mineral ; o segundo lote continha 17 animais com peso inicial de 362+14 kg que receberam suplementação concentrada de 0,125% do peso vivo; e o terceiro lote com 14 animais com peso inicial de 407+24 kg que receberam suplementação de 0,250% do peso vivo. Todos os suplementos continham 24% de proteína bruta, constituídos de milho, farelo de soja e amiréia. Para avaliação do consumo de matéria seca e dos parâmetros ruminais foram utilizados três novilhos com idade de 20 meses e peso médio de 420+25 kg, providos de fístula permanente no rúmen. Os animais que consumiram sal mineral apresentaram consumo médio de 0,070 kg/dia, com ganho de 0,631 kg/dia; os animais do tratamento 0,125% PV apresentaram consumo médio de 0,490 kg/dia de suplemento e ganho de peso de 1,099 kg/dia; os animais do tratamento 0,250% PV consumiram em média 1,100 kg/dia de suplemento e observou-se ganho de peso de 1,161 kg/dia, com conversão do suplemento de 0,91:1 e 10:1 kg de suplemento por kg de ganho de peso, respectivamente, para os tratamentos 0,125 e 0,250% PV. A suplementação em níveis crescentes, durante a terminação de novilhos a pasto, proporcionou maiores ganhos de peso para o nível de 0,250% do PV, porém com melhor conversão do uso do suplemento para o nível de 0,125% do PV. O consumo de matéria seca não foi afetado (P>0,05) pelos diferentes níveis de suplementação. Os teores de amônia e os valores de pH foram afetados (P<0,05) pelo tratamento e pelo horário de avaliação, verificando-se interação entre tratamento x hora. Verificou-se que os valores de pH, para todos os tratamentos, foram superiores ao limite definido para a inibição da digestão da fibra. Os teores de amônia no líquido ruminal para os animais suplementados com 0,125 e 0,250% PV apresentaram-se acima do valor de 10 mg/dL, maximizando o crescimento microbiano e a digestibilidade ruminal em condições tropicais. Para avaliar a composição química e características de carcaça foram abatidos 14 novilhos, com idade de 24 meses e peso médio de 481+30 kg, de diferentes grupos genéticos, sendo sete ½Nelore x ½Santa Gertrudis, quatro ½Nelore x ½Simental e três Nelore. Na avaliação de carcaça, não se observou diferença (P>0,05) entre os diferentes grupos genéticos para as características peso vivo de abate, peso de carcaça, rendimento de carcaça, peso do traseiro especial, rendimento do traseiro especial, peso do dianteiro com cinco costelas e peso da ponta de agulha, espessura de gordura e área de olho de lombo. Houve diferença (P<0,05) para a porcentagem de umidade, cinzas, proteínas, lipídeos totais e colesterol entre os diferentes grupos genéticos. Avaliando-se a composição dos ácidos graxos do músculo Longissimus dorsi, verificou-se maior teor (P<0,05) de ácido linoléico conjugado (CLA) para os animais cruzados ½Nelore x ½Santa Gertrudis, quando comparados aos animais ½Nelore x ½Simental e Nelore. A carne oriunda de animais ½Nelore x ½Santa Gertrudis, terminados a pasto, possui qualidade nutricional superior quando comparada aos outros grupos genéticos.

Two studies were conducted during the grazing season of 1997. Study 1 consisted of three Experiments, and the objectives were to compare milk production and composition, body weight change and body condition score, and to determine time patterns of grazing between cows supplemented with different forms and amounts of corn. Also rumen fermentation parameters were measured in cows supplemented with two different types of corn. In study 2, milk yield was measured when grazing pasture was supplemented to lactating Holstein cows fed a typical TMR diet. Predominantly orchardgrass pastures with lesser amounts of white clover and Kentucky bluegrass were grazed during both studies. In Experiment 1, 36 Holstein cows were supplemented either with 6, 6, 6, or 4 kg/d DM of high moisture corn, coarsely ground corn, finely ground corn, or high moisture corn in two equal feedings, respectively. Milk yield was similar (30.3 kg/d) among treatments. Milk protein (2.97%) and MUN (14.7 mg/dl) did not differ among treatments. Body weight change and body condition score change were similar among treatments (23.1 kg and -0.24). During Experiment 2, four rumen-cannulated cows in mid-lactation were supplemented 6 kg/d DM of either coarsely ground corn or high moisture corn in two equal feedings. After the p.m. milking, ruminal pH was measured and rumen fluid samples were collected to determine ammonia N and VFA. While grazing, this was repeated at 0.5, 1, 2, 3,...8 h post-corn feeding (0 h). Ruminal pH was similar for both corn supplements and was lowest (5.9 and 5.8) at 5 and 8 h, respectively. Rumen ammonia N concentrations started to increase approximately 2 h after cows began grazing, reaching maximum levels 5 h later. In Experiment 3, the number of cows grazing, lying, or standing were recorded every half hour, for two consecutive days, while grazing. Cows grazed an average of 6.4 h/d, 4.1 h in the afternoon and 2.3 h in the morning. Similarity in milk production, milk composition, BW change, and BCS between treatments indicates that the quality and availability of pasture permitted equal response regardless of the type or amount of corn supplemented. Fifty four Holstein cows in mid lactation were used in Study 2. Cows were fed either a TMR diet only, or were fed TMR during half of the day (after the a.m. or p.m. milking according to the treatment) and supplemented with grazing pasture during the other half of the day. Milk production was slightly but significantly higher for cows on the TMR treatment (29.1 vs. 28.2 and 27.6). No significant difference between treatments was observed in FCM (27.7 kg/d), and milk fat (3.47) and protein percentage (3.23). While BW change did not differ among treatments (25.7 kg), body condition score increased more in cows fed only a TMR diet (0.14 vs. -0.06 and 0.01). The TMR intake was significantly different between treatments, being highest for cows on the TMR treatment and lowest for cows grazing after the p.m. milking (26.6 vs. 20.3 vs. 17.5 kg/d DM). Income over feed cost differed between treatments, and was approximately 15.3% higher for cows supplemented with high quality pasture during the afternoon compared to cows on TMR. Dairy farmers may obtain economical benefits by practicing this type of management during the grazing season with little effect on milk yield. / Master of Science