• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 37
  • 5
  • 4
  • 2
  • Tagged with
  • 54
  • 23
  • 21
  • 16
  • 13
  • 12
  • 12
  • 11
  • 11
  • 10
  • 10
  • 10
  • 10
  • 9
  • 9
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Exigências dietárias e disponibilidade de fontes de fósforo para tilápia do Nilo (Oreochromis niloticus)

Pinto, Luis Gabriel Quintero [UNESP] 28 July 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-28Bitstream added on 2014-06-13T19:22:49Z : No. of bitstreams: 1 pinto_lgq_dr_botfmvz.pdf: 430417 bytes, checksum: 842821d6558c1e81835942c980421262 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A absorção aparente dos nutrientes contidos em alguns ingredientes protéicos e fosfatos inorgânicos, pela tilápia do Nilo, foi comparada em três diferentes fases de crescimento. Os ingredientes testados foram farinha de peixe, farinha de vísceras de aves, farinha de carne e ossos, glúten de milho, farelo de soja, farelo de algodão, fosfato mono bicálcico, fosfato bicálcico, fosfato mono potássico e ácido fosfórico. A absorção de nutrientes foi determinada com peixes representando as fases de desenvolvimento: crescimento (25g), engorda (250g) e acabamento (500g). Concluiu-se que a capacidade da tilápia do Nilo para digerir os alimentos e absorver os nutrientes é dependente do peso corporal e das características do alimento avaliado; houve tendência de melhor aproveitamento de nutrientes dos alimentos de origem animal e fontes inorgânicas pelos peixes juvenis. Os peixes em engorda e acabamento mostraram melhor aproveitamento dos nutrientes das fontes protéicas de origem vegetal, quando comparados com os peixes mais novos. / Apparent absorption of nutrients contained in several protein ingredients and inorganic phosphates by Nile tilapia were compared in three different stage growth. The ingredients tested were fish meal, chicken by-product meal, meat and bone meal, corn gluten, soybean meal, cotton seed meal, mono-bi-calcium phosphate, bi-calcium phosphate, mono-potassium phosphate and phosphoric acid. Nutrient absorption was determined by fish in three different stage of growth cycle: nursery phase (25g), growout-I phase (250g) and growout-II phase (500g). It was concluded that, the ability of Nile tilapia to digest feed and absorb nutrients is dependent on body weight and characteristics of food evaluated; there was better utilization of nutrients from animal protein and inorganic sources for fish in nursery phase; growout I and growout II phases showed better use of protein plant sources, when compared with younger fish.
12

Stratégies de limitation de l'ingestion : optimisation des performances zootechniques, impacts physiologiques et conséquences sur la santé digestive / Feed intake limitation strategies : optimization of growth performances, physiological impacts and consequences on digestive health

Knudsen, Christelle 16 December 2014 (has links)
Dans un contexte de limitation de l'utilisation des antibiotiques, de nouvelles stratégies doivent être mises en place pour préserver la santé des animaux, en particulier lors du sevrage. En cuniculture, les stratégies de limitation de l'ingestion permettent de réduire les troubles digestifs en post sevrage et améliorent l'efficacité alimentaire, mais induisent inévitablement un retard de croissance et une baisse du rendement à l'abattage. Ce travail de thèse avait pour objectif d'une part d'optimiser les performances de croissance et de rendement à l'abattage des animaux soumis à une restriction alimentaire via une modulation de la quantité et de la qualité énergétique des aliments et d'autre part d'expliciter les mécanismes physiologiques sous-jacents aux effets bénéfiques d'une ingestion restreinte sur la santé et l'efficacité alimentaire. Nous avons démontré que dans le cadre d'une stratégie de restriction alimentaire un aliment riche en énergie digestible permet d'optimiser la croissance (+2%), le rendement à l'abattage (+0,6 points) et l'efficacité alimentaire (+11%), via notamment une amélioration de l'efficacité digestive, sans pénaliser les paramètres sanitaires, mais ne permet de rattraper que partiellement le retard de croissance induit par la restriction alimentaire (-3% de poids à l'abattage par rapport aux animaux nourris à volonté). Un aliment riche en amidon était favorable à la croissance de ces animaux et en particulier au rendement à l'abattage et n'avait pas d'effet délétère sur les paramètres sanitaires. La restriction alimentaire et la concentration énergétique alimentaire dans une moindre mesure, modulaient la réponse immunitaire via une réduction de la réponse humorale digestive (IgA intestinaux) et systémique (IgA et IgG circulants) sans modification de la réponse inflammatoire. L'activité du microbiote caecal était quant à elle modulée par la masse d'aliment ingérée alors que le profil de la communauté bactérienne caecale, sa diversité et sa richesse ne semblaient pas modifiés par la restriction alimentaire. Toutefois l'abondance relative de certaines familles (Eubacteriaceae, Peptococcaceae et Christensenellaceae) et genres montraient des variations spécifiques à la restriction ou à la concentration énergétique de l'aliment. L'ensemble de ces résultats indiquent que les relations entre les mesures physiologiques et les effets bénéfiques de la restriction alimentaire sur la santé digestive restent complexes et suggèrent l'implication d'autres paramètres métaboliques non évalués. Des hypothèses complémentaires de travail doivent ainsi être envisagées Toutefois nos travaux établissent l'intérêt économique de la restriction alimentaire, quel que soit le contexte sanitaire, et celui de l'utilisation d'aliments à haute valeur énergétique sur les performances zootechniques. Notre étude ouvre dès lors des perspectives de recherches complémentaires d'optimisation des stratégies alimentaires via une modulation de la durée de restriction alimentaire et de la qualité énergétique des aliments. / With the reduction in antibiotic use new strategies are required in order to preserve animal health, particularly around weaning. In rabbit breading feed restriction strategies allow for the reduction of post-weaning digestive disorders and improve feed efficiency, but are inevitably responsible for a reduced growth and carcass yield at slaughter. This work aimed to optimize the growth performances and slaughter yield of restricted fed rabbits through a modulation of the dietary energy concentration and quality. The second objective of this work was to explain the physiological mechanisms underlying the beneficial effects of feed restriction upon health and feed efficiency. We demonstrated that, under a restriction strategy, a diet rich in digestible energy increased growth (+2%), slaughter yield (+0.6 points) and feed efficiency (+11%), through an improved digestive efficiency, without penalizing the sanitary parameters. The reduced growth induced by feed restriction was however only partially compensated for (-3% in final weight compared to the ad libitum fed animals). A diet rich in starch induced a higher growth and slaughter yield and did not penalize the sanitary parameters under a restriction strategy. Feed restriction and, to a lesser extent, the dietary energy concentration, modulated the immune response through a reduced humoral response at the digestive (fecal IgA) and systemic (plasmatic IgA and IgG) levels without modifying the inflammatory response. The cecal microbial activity was modulated by the amount of feed ingested while the cecal bacterial community profile, diversity and richness were not affected by the feed intake level. However, the relative abundance of certain families (Eubacteriaceae, Peptococcaceae and Christensenellaceae) and generas demonstrated specific variations according to the feed intake level and the dietary energy concentration. These results indicate that the relationship between the physiological measurements and the beneficial effects of feed restriction upon health remain complex and suggest the implication of other metabolic parameters that weren't measured. Complementary work hypothesis must therefore be considered. This work however enabled us to establish the economic advantage of feed restriction strategies regardless of the sanitary status and demonstrated the beneficial effects of a high energy diet on growth parameters. Our study opens the door to new complementary research projects regarding the optimization of the feeding strategies through for instance the modulation of the restriction length and the dietary energy quality.
13

Isolation and characterization of prebiotic oligosaccharides from algal extracts and their effect on gut microflora

Hadebe, Nontando January 2016 (has links)
Submitted in partial fulfillment for the Degree of Master of Applied Sciences in Biotechnology, Durban University of Technology, Durban, South Africa, 2016. / Prebiotics are defined as non-digestible oligosaccharides (NDOs) or polysaccharides (NDPs), which promote the growth of beneficial lactic acid bacteria in the colon. Algae are rich in polysaccharides and can be exploited as prebiotics for functional food ingredients to improve human and animal health. Currently, inulin is the most widely used ingredient in the prebiotics market, which is produced from live plants and requires expensive production processing. There is a vast repository of marine life with algae as a major source of nutrients. Therefore, this study provides an alternative source for prebiotic production and examines marine and freshwater algae that promote the growth of two strains of Lactobacillus delbrueckii subs. (Lactobacillus lactis and Lactobacillus bulgaricus) and one strain of Bifidobacterium spp. (Bifidobacterium longum). Monosaccharides of the oligosaccharide fraction of marine and freshwater algal extracts were investigated with the use of thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) after acidic hydrolysis of cell matrix polysaccharides. A total of fifty-five marine and freshwater aqueous algal extracts were assessed for their effect on the growth of L. lactis, B. longum and L. bulgaricus over a 96 hour period. Relative to the negative control, 34.5% algal extracts showed improved growth on one or more probiotic bacteria. The optimum time for maximum bacterial growth was noted at 48 h for all the tested aqueous algal extracts. Five marine and freshwater algal cultures (Spirulina platensis, Chlorococcum spp., Dunaliella salina, Scenedesmus magnus, Chlorella spp. and algal extract no. 48) from various aquatic environments in Kwa-Zulu Natal showed the best growth dynamics and demonstrated the greatest potential as sources of biomass for prebiotic production. These algal extracts were able to significantly increase the growth of at least one of the three probiotic bacteria (p < 0.05). Aqueous algal extract from S. platensis was regarded as the best algal source for prebiotics as it demonstrated a greater stimulatory effect on the growth of all three probiotic bacteria (L. lactis, B. longum and L. bulgaricus) compared to tested aqueous algal extracts and the inulin used as a positive control. The results obtained by HPLC for characterization confirmed TLC data, as xylose and galactose were detected by both chromatograms. These data indicated that xylose and galactose were present in aqueous algal extracts from S. magnus and S. platensis and galactose in aqueous algal extract no. 48. Xylose was most abundant in aqueous algal extracts from S. platensis (3mg/ml) and S. magnus (2.3mg/ml). In conclusion aqueous algal extracts from S. platensis, Chlorococcum, D. salina, S. magnus, Chlorella and algal extract no. 48 are potential sources for prebiotic production. Spirulina platensis extract was regarded as the best algal source. Xyose and galactose characterized by HPLC in algal extracts make up oligosaccharides that function as prebiotic compounds for stimulation of probiotic bacteria. There is a great scope for successful production of prebiotics from algal sources in South Africa. / M
14

Eficiência marginal da lisina digestível das dietas para suínos em crescimento e terminação : um estudo meta-analítico / Marginal efficiency of digestible lysine diets for growing-finishing pigs : a meta-analytical study

Melchior, Raquel January 2016 (has links)
Inúmeros trabalhos avaliando as exigências de lisina podem ser encontrados na literatura, mas seus resultados são heterogêneos. Revisões sistemáticas e a meta-análise permitem integrar diferentes variáveis, gerar novos resultados e obter respostas ajustadas a uma maior diversidade experimental. Objetivou-se explorar as relações da lisina digestível com as variáveis de desempenho, estabelecer a exigência e avaliar a eficiência marginal da lisina segundo a lei de rendimentos decrescentes para suínos em crescimento e terminação. Para os estudos I e II, foram compilados 36 artigos publicados entre 2002 e 2013 avaliando 2.399 suínos pesando entre 15-120 kg. Para o estudo III, foram utilizados 26 artigos que avaliaram 1.820 suínos pesando entre 20-120 kg. No estudo I, o consumo diário de lisina apresentou correlações maiores com a ingestão de energia metabolizável e proteína bruta e com as deposições de proteína e lipídios. O consumo diário de lisina apresentou melhor ajuste nas equações de variância-covariância do que o nível percentual de lisina. No estudo II, o aumento no consumo diário de lisina melhorou o ganho de peso e a deposição de proteína na fase de 70-120 kg. Nas fases de 15-30; 30-70 e 70-120 kg os níveis de lisina digestível determinados para obter as melhores respostas de ganho corresponderam ao consumo diário de 14,8; 20,2 e 18,3 g lisina/dia. Os níveis de lisina digestível determinados para obter as melhores respostas de deposição de proteína corresponderam ao consumo diário de 16,3 e 24,1 g lisina/dia nas fases 15-30 e 30-70 kg. No estudo III, observamos que a medida que o animal se aproxima ou atinge o ponto de máximo desempenho, a eficiência de uso da lisina digestível diminui segundo a lei de rendimentos decrescentes. Dietas formuladas para atender 95% da máxima resposta de ganho de peso permitem uma melhora na eficiência marginal de uso da lisina da ordem de 2,4; 2,5 e 1,5 g de ganho de peso para cada g de lisina ingerida nas faixas de peso vivo 20-50; 50-70 e 70-120 kg. Sugerimos a inclusão de variáveis como a eficiência alimentar e o ganho de peso nas análises de determinação de exigências de lisina, também a escolha de metodologias analíticas adequadas e a inclusão da lei de rendimentos decrescentes da eficiência marginal de uso da lisina nos atuais modelos de determinação de exigência para evitar a superestimação observada nas tabelas de recomendação nutricional. / Several studies evaluating the lysine requirements are avaible in the literature, but its results are heterogeneous. Systematic reviews and meta-analysis allows integrating different variables, generating new results and producing answers adjusted to experimental diversity. This objective of this study was to explore the relationship among dietary lysine and the performance variables, establishing the requirement and assessing the marginal efficiency of dietary lysine according to the law of diminishing returns for growing-finishing pigs. For studies I and II, 36 articles published from 2002 to 2013 evaluating 2399 pigs weighing between 15-120 kg were compiled. And for the study III 26 articles evaluating 1820 pigs weighing between 20-120 kg were used. In the study I, daily intake of lysine showed higher correlations with the metabolizable energy intake and crude protein, with the protein deposition and lipid deposition. The daily intake of lysine showed better adjustment in the variance-covariance equations than the dietary level of lysine. In Study II, increasing the daily intake of lysine improved the weight gain and protein deposition in the 70-120 kg phase. In 15-30; 30-70 and 70-120 kg phase the levels digestible lysine that maximized weight gain reponse corresponded to the daily intake of 14.8; 20.2 and 18.3 g lysine/day. Lysine levels that maximized protein deposition reponse corresponded to daily intake of 16.3 and 24.1 g lysine/day in the phases 15-30 and 30-70 kg. In the study III, it was observed that, as the animal approaches or reaches the maximum performance the efficiency of lysine use decreases according to the law of diminishing returns. Diets formulated to meet 95% of the maximal weight gain response permit a marginal improvement in efficiency of use of the lysine the order of 2.4; 2.5 and 1.5 grams of weight gain for each lysine grams ingested in live weight phases 20-50; 50-70 and 70-120 kg respectively. It suggest the inclusion of variables feed efficiency and weight gain in analysis for the determination of lysine requirements, also the choice of appropriate analytical methods and the inclusion of diminishing returns law of marginal efficiency the dietary lysine in current models for the determination of requirements to avoid the overestimation observed in nutritional recommendation tables.
15

Valor nutricional do farelo de arroz integral para frangos de corte de crescimento lento / Nutritional value of brown rice bran for slow-growing broilers

Gasparini, Sandra Paula 27 March 2014 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-06-22T19:13:45Z No. of bitstreams: 1 SandraGasparini.pdf: 349340 bytes, checksum: 0464691b140faa8019f9a16a1192d667 (MD5) / Made available in DSpace on 2017-06-22T19:13:45Z (GMT). No. of bitstreams: 1 SandraGasparini.pdf: 349340 bytes, checksum: 0464691b140faa8019f9a16a1192d667 (MD5) Previous issue date: 2014-03-27 / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA) / Two experiments to determine the metabolizable energy in different ages and true digestibility of amino acids of rice bran (RB), broiler slow growth were performed. In the first experiment, 352 birds were distributed in a completely randomized design with three treatments and six replicates of eight or six birds per experimental unit as experimental age. The RB replaced 40% references diets formulated for three age groups (1-30, 31-60 and 61-90 days). The method used was the total collection and 1.0% iron oxide was used as a fecal marker. In the second experiment, 168 birds at 41 days of age fed a diet free of protein (DFP) and formulated with 55% of RB as the sole source of dietary crude protein and amino acids were used. All birds were killed by cervical dislocation and open the abdominal cavity to collect the contents at the terminal ileum portion. The samples were sent for amino acid analysis using HPLC. Was used 0.5% of chromic oxide as a marker for determining the digestibility of amino acids of the RB and the endogenous excretion of amino acids. The mineral content of the RB, with a value of 3.94%, below those content presented in the literature. The apparent metabolizable energy, true and true corrected for nitrogen balance, found for the RB in birds 70-79 days of age (2,801, 3,002 and 2,394 kcal / kg, respectively), statistically different (P <0.05) from values obtained with birds 40-49 days (2,415, 2,566 and 2,427 kcal / kg, respectively) and birds 10-19 days of age (2,131, 2,266 and 2,214 kcal / kg, respectively). The coefficients of apparent metabolism of dry matter (CMADM), with values of 65.80% (70 to 79 days), 59.20% (40 to 49 days) and 53.10% (10 to 19 days of age), statistically different (P <0.05). The coefficient of real gross energy metabolization corrected for nitrogen balance (CMVGEn), found in birds 70-79 days (56.40%), statistically different (P <0.05) of the value found in poultry 10 to 19 days of age (49.10%). Thus, in the formulation of rations, should be considered the differences in energy values of RB for young and adult birds, because the digestibility of dry matter and gross energy, increases with age. The average true digestibility of amino acids of the RB was 79.5%, as fed, where the methionine had the lowest coefficient of true digestibility, with a value of 78.12% and the highest arginine, with a value of 82.10 %. The true digestible values were 0.51% for lysine, 0.18% for methionine, 0.41% for methionine + cystine, 0.39% for threonine and 0.52% for valine. / Foram realizados dois experimentos com o objetivo de determinar a energia metabolizável em diferentes idades e a digestibilidade verdadeira dos aminoácidos do farelo de arroz integral (FAI), para frangos de corte de crescimento lento. No primeiro experimento, 352 aves foram distribuídas em delineamento inteiramente casualizado com três tratamentos e seis repetições de oito ou seis aves por unidade experimental, conforme idade experimental. O FAI substituiu em 40% as dietas referências, formuladas para três idades (1 a 30, 31 a 60 e 61 a 90 dias). O método utilizado foi o de coleta total de excretas e 1,0% de óxido de ferro foi utilizado como marcador fecal. No segundo experimento, foram utilizadas 168 aves com 41 dias de idade, alimentadas com uma dieta isenta de proteína (DIP) e uma dieta formulada com 55% de FAI como única fonte de proteína bruta e aminoácidos. Todas as aves foram abatidas por deslocamento cervical e abertas na cavidade abdominal para coleta do conteúdo na porção íleo terminal. As amostras foram enviadas para análise de aminoácidos utilizando o HPLC. Foi utilizado 0,5% de óxido de cromo como indicador para determinação dos coeficientes de digestibilidade dos aminoácidos do FAI e da excreção endógena de aminoácidos. O conteúdo mineral do FAI, com valor de 3,94%, apresentou teor abaixo daqueles descritos na literatura. Os valores de energia metabolizável aparente, verdadeira e verdadeira corrigida para o balanço de nitrogênio, encontrados para o FAI em aves de 70 a 79 dias de idade (2.801, 3.002 e 2,394 kcal/kg, respectivamente), diferiram estatisticamente (P<0,05) dos valores obtidos com aves de 40 a 49 dias (2.415, 2.566 e 2.427 kcal/kg, respectivamente) e aves de 10 a 19 dias de idade (2.131, 2.266 e 2.214 kcal/kg, respectivamente). Os coeficientes de metabolização aparente da matéria seca (CMAMS), com valores de 65,80% (70 a 79 dias), 59,20% (40 a 49 dias) e 53,10% (10 a 19 dias de idade), diferiram estatisticamente (P<0,05). O valor do coeficiente de metabolização verdadeiro da energia bruta corrigido para o balanço de nitrogênio (CMVEBn), encontrado em aves de 70 a 79 dias (56,40%), diferiu estatisticamente (P<0,05) do valor encontrado em aves de 10 a 19 dias de idade (49,10%). Assim, nas formulações de rações, devem ser consideradas as diferenças nos valores energéticos do FAI para aves jovens e adultas, pois a digestibilidade da matéria seca e da energia bruta, aumenta com a idade. O valor médio de digestibilidade verdadeira dos aminoácidos do FAI foi de 79,5%, na matéria natural, onde a metionina apresentou o menor coeficiente de digestibilidade verdadeira, com valor de 78,12% e a arginina o maior, com valor de 82,10%. Os valores digestíveis verdadeiros foram de 0,51% para lisina, 0,18% para metionina, 0,41% para metionina+cistina, 0,39% para treonina e 0,52% para valina.
16

Exigências de valina para frangos de corte / Requirements of valine for broilers

Ferreira, Nayara Tavares 15 December 2011 (has links)
O presente estudo teve como objetivo avaliar níveis ótimos de valina digestível. Foram conduzidos três ensaios com frangos de corte da linhagem Cobb nas fases inicial (1-14 dias), crescimento (14-28 dias) e terminação (28-42 dias), com ensaios realizados separadamente para cada fase, tendo como base o método dose-resposta. Para os ensaios de 1 a 14dias e de 14 a 28 dias, 672 amimais foram distribuídos em delineamento inteiramente ao acaso, em oito tratamentos (7 níveis de valina e 1 controle), com 7 repetições, sendo cada unidade experimental composta por 12 aves , porém no ensaio de 28 a 42 dias foram utilizados 560 frangos, igualmente distribuídos como nos ensaios anteriores em 8 tratamentos com 7 repetições com 10 aves cada. Foram formuladas dietas basais pela técnica da diluição, deficientes em valina, contendo níveis de energia, minerais e vitaminas conforme recomendações de Rostagno et al. (2005), para cada fase. As recomendações dos níveis de valina digestível para cada fase, obtidas no presente estudo, foram realizadas com base nas respostas de CA. As recomendações obtidas pelo método dose resposta são de 0,917; 0,905 e 0,783% de valina digestível para frangos de 1 a 14 dias, 14 a 28 e 28 a 42 dias de idade, respectivamente. / This study was to evaluate optimal levels of digestible valine. Three trials were conducted with broiler chickens of Cobb in the initial phase (1-14 days), growth (14-28 days) and termination (28-42 days), with tests performed separately for each phase, based on the method dose-response. For tests 1 to 14 days and 14 to 28 days, 672 animals it were distributed in a completely randomized in eight treatments (seven levels of valine and 1 control), with 7 replicates, each replicate consisting of 12 birds but the test of 28 to 42 days 560 chickens were used, equally distributed as in previous trials in 8 treatments with 7 replicates of 10 birds each. Basal diets were formulated by the dilution technique, deficient in valine, containing levels of energy, minerals and vitamins as recommended by Rostagno et al. (2005), for each phase. The recommended levels of digestible valine for each phase, obtained in this study were based on responses from CA. The recommendations obtained by the dose response are 0.917, 0.905 and 0.783% of digestible valine for broilers from 1-14 days, 14-28 and 28-42 days of age, respectively.
17

Non digestible carbohydrates in the diet determine toxicity of irinotecan (CPT-11)/5-fluorouracil in rats independently of β-glucuronidase activity in intestinal lumen

Farhangfar, Arazm Unknown Date
No description available.
18

Equações de predição dos valores energéticos do milho e do farelo de soja para suínos em crescimento com validação ex post / Prediction equations of energy values of corn and soybean meal for growing pigs with ex post validation

Ellery, Everardo Ayres Correia January 2013 (has links)
ELLERY, Everardo Ayres Correia. Equações de predição dos valores energéticos do milho e do farelo de soja para suínos em crescimento com validação ex post. 2013. 55 f. Dissertação (Mestrado em zootecnia)- Universidade Federal do Ceará, Fortaleza-CE, 2013. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-05-06T19:04:26Z No. of bitstreams: 1 2013_dis_eacellery.pdf: 893066 bytes, checksum: 2cec15703d25a6fa87de6e00137ec7af (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-05-27T19:37:53Z (GMT) No. of bitstreams: 1 2013_dis_eacellery.pdf: 893066 bytes, checksum: 2cec15703d25a6fa87de6e00137ec7af (MD5) / Made available in DSpace on 2016-05-27T19:37:53Z (GMT). No. of bitstreams: 1 2013_dis_eacellery.pdf: 893066 bytes, checksum: 2cec15703d25a6fa87de6e00137ec7af (MD5) Previous issue date: 2013 / The aim of this study was to determine and validate prediction equations for digestible (DE) and metabolizable energy (ME) of corn and soybean meal for growing pigs. The prediction equations were developed using data from chemical composition and digestibility and metabolizability of 30 and 25 samples of corn grain and soybean meal, respectively, evaluated in experiments at the Embrapa Suínos e Aves. The equations were estimated through regression analysis, using the REG procedure of SAS and adjusted R² was the criterion of choice to select the best models. Two equations were estimated for DE and two for ME, of corn and soybean meal. To validate the equations, two experiments were performed to determine the values of DE and ME with five samples of corn grain (Experiment I) and five samples of soybean meal (Experiment II). In each experiment, 48 growing pigs with an initial weight of 54,21±1,68 kg (Experiment I) and 54.40 ± 1.76 kg (Experiment II), were sorted in a complete randomized block design with 6 treatments (Experiment I: 1 reference diet and 5 test diets composed of 60% of the reference diet and 40% corn, and Experiment II: 1 reference diet and 5 test diets composed of 70% of the reference diet and 30% soybean meal) and 8 replicates. The experimental unit was the animal. Based on the DE and ME values obtained in the experiments, and in the predicted values obtained with the equations, we proceeded to validate the equations, using the REG procedure of SAS. The criterion for selection of the best model was the lowest prediction error (pe). After validation, the equations that best fit to estimate the digestible and metabolizable energy of corn for growing pigs were: DE = 11812 – (1015.9CP) – (837.9EE) – (1641ADF) + (2616.3Ash) + (47.5CP2) + (114.7CF2) + (46ADF2) – (1.6NDF2) – (997.1Ash2) + (151.9EECF) + (23.2EENDF) – (126.4CPCF) + (136.4CPADF) – (4.0CPNDF), with R2 = 0.81; pe = 2.33 and ME = 12574 – (1254.9CP) – (1140.5EE) – (1359.9ADF) + (2816.3Ash) + (77.6CP2) + (92.3CF2) + (54.1ADF2) – (1.8NDF2) – (1097.2Ash2) + (240.6EECF) + (26.3EENDF) – (157.4CPCF) + (96.5CPADF) – (4.4CPNDF), with R2 = 0.89 e pe = 2.24. For soybean meal the equations that best fit were: DE = 48153 – (1586,1CP) + (744,5EE) + (363,6CF) – (1398,3Ash) + (15,5CP2) – (170,8EE2) – (29,3CF2) + (5,4ADF2) – (2,5NDF2) + (90,6Ash2) – (48,2EEADF) + (33EENDF), with R² = 0.88 and pe = 2.32 e ME = 12692 – (2397,7Ash) – (56,8EE2) + (164,9Ash2) – (102,2EECF) – (12,2EEADF) + (67,6EENDF) + (5,5CPCB) – (2,9CPNDF), with R2 = 0.65 and pe = 1.69. / Com esse estudo objetivou-se determinar e validar equações de predição para energia digestível (ED) e metabolizável (EM) do milho e do farelo de soja com suínos em crescimento. Para obtenção das equações de predição foram utilizados dados de composição química, digestibilidade e metabolizabilidade de 30 amostras de grãos de milho e 25 amostras de farelo de soja avaliadas em experimentos na Embrapa Suínos e Aves, sendo as equações estimadas por meio da análise de regressão, utilizando-se o procedimento REG do pacote estatístico SAS e o R² ajustado como critério de escolha para selecionar os melhores modelos. Foram estimadas duas equação para ED e duas para EM, do milho e do farelo de soja. Para a validação das equações foram realizados dois experimentos para a determinação dos valores de ED e EM de cinco amostras de milho (Experimento I) e cinco amostras de farelo de soja (Experimento II). Em cada experimento, 48 leitões machos castrados, com peso inicial de 54,21±1,68 kg (Experimento I) e 54,40±1,76 kg (Experimento II), foram distribuídos em um delineamento em blocos ao acaso, com 6 tratamentos (Experimento I: 1 ração referência e 5 rações testes, compostas por 60% da dieta referência e 40% de diferentes milhos e para o Experimento II: 1 ração referência e 5 rações testes, compostas por 70% da dieta referência e 30% de diferentes farelos de soja) e 8 repetições, sendo a unidade experimental constituída por um animal. Com base nos resultados de ED e EM obtidos nos experimentos e os valores preditos nas equações, procedeu-se a validação das equações, utilizando-se o procedimento REG do programa SAS, sendo o critério de seleção o menor erro de predição (ep). Após a validação, as equações que melhor se ajustaram para predição dos valores de energia digestível e metabolizável do milho para suínos em crescimento foram as seguintes: ED = 11812 – 1015,9(PB) – 837,9(EE) – 1641(FDA) + 2616,3(MM) + 47,5(PB2) + 114,7(FB2) + 46(FDA2) – 1,6(FDN2) – 997,1(MM2) + 151,9(EEFB) + 23,2(EEFDN) – 126,4(PBFB) + 136,4(PBFDA) – 4,0(PBFDN), com R2 de 0,81 e ep = 2,33 e EM = 12574 – 1254,9(PB) – 1140,5(EE) – 1359,9(FDA) + 2816,3(MM) + 77,6(PB2) + 92,3(FB2) + 54,1(FDA2) – 1,8(FDN2) – 1097,2(MM2) + 240,6(EEFB) + 26,3(EEFDN) – 157,4(PBFB) + 96,5(PBFDA) – 4,4(PBFDN), com R2 de 0,89 e ep = 2,24. Para o farelo de soja as equações que melhor se ajustaram foram: ED = 48153 – 1586,1(PB) + 744,5(EE) + 363,6(FB) – 1398,3(MM) + 15,5(PB2) – 170,8(EE2) – 29,3(FB2) + 5,4(FDA2) – 2,5(FDN2) + 90,6(MM2) – 48,2(EEFDA) + 33(EEFDN), com R² de 0,88 e o ep = 2,32, EM=12692 – 2397,7(MM) – 56,8(EE2) + 164,9(MM2) – 102,2(EEFB) – 12,25(EEFDA) + 67,6(EEFDN) + 5,5(PBFB) – 2,9(PBFDN) com R2 de 0,65 e o ep = 1,69.
19

Eficiência marginal da lisina digestível das dietas para suínos em crescimento e terminação : um estudo meta-analítico / Marginal efficiency of digestible lysine diets for growing-finishing pigs : a meta-analytical study

Melchior, Raquel January 2016 (has links)
Inúmeros trabalhos avaliando as exigências de lisina podem ser encontrados na literatura, mas seus resultados são heterogêneos. Revisões sistemáticas e a meta-análise permitem integrar diferentes variáveis, gerar novos resultados e obter respostas ajustadas a uma maior diversidade experimental. Objetivou-se explorar as relações da lisina digestível com as variáveis de desempenho, estabelecer a exigência e avaliar a eficiência marginal da lisina segundo a lei de rendimentos decrescentes para suínos em crescimento e terminação. Para os estudos I e II, foram compilados 36 artigos publicados entre 2002 e 2013 avaliando 2.399 suínos pesando entre 15-120 kg. Para o estudo III, foram utilizados 26 artigos que avaliaram 1.820 suínos pesando entre 20-120 kg. No estudo I, o consumo diário de lisina apresentou correlações maiores com a ingestão de energia metabolizável e proteína bruta e com as deposições de proteína e lipídios. O consumo diário de lisina apresentou melhor ajuste nas equações de variância-covariância do que o nível percentual de lisina. No estudo II, o aumento no consumo diário de lisina melhorou o ganho de peso e a deposição de proteína na fase de 70-120 kg. Nas fases de 15-30; 30-70 e 70-120 kg os níveis de lisina digestível determinados para obter as melhores respostas de ganho corresponderam ao consumo diário de 14,8; 20,2 e 18,3 g lisina/dia. Os níveis de lisina digestível determinados para obter as melhores respostas de deposição de proteína corresponderam ao consumo diário de 16,3 e 24,1 g lisina/dia nas fases 15-30 e 30-70 kg. No estudo III, observamos que a medida que o animal se aproxima ou atinge o ponto de máximo desempenho, a eficiência de uso da lisina digestível diminui segundo a lei de rendimentos decrescentes. Dietas formuladas para atender 95% da máxima resposta de ganho de peso permitem uma melhora na eficiência marginal de uso da lisina da ordem de 2,4; 2,5 e 1,5 g de ganho de peso para cada g de lisina ingerida nas faixas de peso vivo 20-50; 50-70 e 70-120 kg. Sugerimos a inclusão de variáveis como a eficiência alimentar e o ganho de peso nas análises de determinação de exigências de lisina, também a escolha de metodologias analíticas adequadas e a inclusão da lei de rendimentos decrescentes da eficiência marginal de uso da lisina nos atuais modelos de determinação de exigência para evitar a superestimação observada nas tabelas de recomendação nutricional. / Several studies evaluating the lysine requirements are avaible in the literature, but its results are heterogeneous. Systematic reviews and meta-analysis allows integrating different variables, generating new results and producing answers adjusted to experimental diversity. This objective of this study was to explore the relationship among dietary lysine and the performance variables, establishing the requirement and assessing the marginal efficiency of dietary lysine according to the law of diminishing returns for growing-finishing pigs. For studies I and II, 36 articles published from 2002 to 2013 evaluating 2399 pigs weighing between 15-120 kg were compiled. And for the study III 26 articles evaluating 1820 pigs weighing between 20-120 kg were used. In the study I, daily intake of lysine showed higher correlations with the metabolizable energy intake and crude protein, with the protein deposition and lipid deposition. The daily intake of lysine showed better adjustment in the variance-covariance equations than the dietary level of lysine. In Study II, increasing the daily intake of lysine improved the weight gain and protein deposition in the 70-120 kg phase. In 15-30; 30-70 and 70-120 kg phase the levels digestible lysine that maximized weight gain reponse corresponded to the daily intake of 14.8; 20.2 and 18.3 g lysine/day. Lysine levels that maximized protein deposition reponse corresponded to daily intake of 16.3 and 24.1 g lysine/day in the phases 15-30 and 30-70 kg. In the study III, it was observed that, as the animal approaches or reaches the maximum performance the efficiency of lysine use decreases according to the law of diminishing returns. Diets formulated to meet 95% of the maximal weight gain response permit a marginal improvement in efficiency of use of the lysine the order of 2.4; 2.5 and 1.5 grams of weight gain for each lysine grams ingested in live weight phases 20-50; 50-70 and 70-120 kg respectively. It suggest the inclusion of variables feed efficiency and weight gain in analysis for the determination of lysine requirements, also the choice of appropriate analytical methods and the inclusion of diminishing returns law of marginal efficiency the dietary lysine in current models for the determination of requirements to avoid the overestimation observed in nutritional recommendation tables.
20

Critérios de avaliação das exigências em treonina, triptofano, valina e isoleucina para frangos de corte de 22 a 42 dias de idade

Duarte, Karina Ferreira [UNESP] 03 July 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-03Bitstream added on 2014-06-13T19:04:39Z : No. of bitstreams: 1 duarte_kf_dr_jabo.pdf: 413050 bytes, checksum: 2d6d9cfb8e49274f4b726645266116bb (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Quatro experimentos foram conduzidos no Setor de Avicultura da Faculdade de Ciências Agrárias e Veterinárias – Campus de Jaboticabal- SP, com o objetivo de estabelecer diferentes critérios de avaliação das exigências dos aminoácidos digestíveis treonina, triptofano, valina e isoleucina para frangos de corte de 22 a 42 dias de idade. Em cada experimento foram utilizados 1.920 frangos de corte machos com 22 dias de idade da linhagem “Cobb”, distribuídos em um delineamento inteiramente ao acaso, com seis tratamentos e oito repetições de 40 aves cada. Os tratamentos consistiram no fornecimento de dietas formuladas com base em aminoácidos digestíveis contendo seis diferentes níveis do aminoácido em estudo. Foram avaliados os dados de desempenho (ganho de peso, consumo de ração, conversão alimentar e viabilidade criatória) e as características de carcaça (rendimento de carcaça, de peito, de coxas+sobrecoxas, de dorso e de asas). Para a determinação das exigências do aminoácido estudado, foram utilizados três modelos de regressão: o modelo quadrático, o modelo exponencial e o de retas segmentadas ou broken line (“linha quebrada”), com 90% do quadrado máximo, estabelecendo equações principalmente para ganho de peso e conversão alimentar. Em caso de significância estatística, foi adotado também o procedimento de comparação das médias pelo Teste de Duncan a 5% de probabilidade. Com base no comportamento dos dados os níveis de 0,7642 e 0,7514% de treonina digestível (treonina:lisina digestíveis de 71,19% e 70,00%), determinados pelo modelo broken line e pelo teste de Duncan a 5% de probabilidade respectivamente, promoveram os melhores resultados de conversão alimentar. O triptofano digestível, quando no nível de 0,2255% (triptofano:lisina digestíveis de 21%) indicou melhora na conversão alimentar e os níveis de 0,1825 e 0,1919%... / Four experiments were conducted to establish different criteria for evaluation the requirements in threonine, tryptophan, valine and isoleucine for broilers from 22 to 42 days of age. In each experiment it was used 1,920 male broilers (Cobb) in a completely randomized design, with six treatments and eight replications of 40 birds each. The treatments consisted in supply diets formulated according to the ideal protein concept and digestible amino acids, with six different levels of the related amino acid. The data from performance and characteristics of carcass had been evaluated. It was used three regression models: quadratic, exponential and broken line, stablishing equations mainly to body weight and feed conversion. In case of significant statistics, it was used the procedure for means comparison using Duncan test (0.05%). The threonine levels of 0.7642 and 0.7515% (threonine:lysine of 71.19% and 70.00%) determined by broken line and Duncan test respectively, showed better results for feed conversion. For digestible tryptophan at the level of 0.2255% (tryptophan:lysine of 21%) indicated a increase in feed conversion and the levels of 0.1825 and 0,1919 (tryptophan:lysine of 17.88% and 17.00%) determined by Duncan test and quadratic equation respectively, indicated the best results for carcass yield. Digestible valine at the level of 0.7729% (valine:lysine of 72.00) determined by Duncan test, showed the best results for feed intake and viability. At the level of 0.8802% (valine:lysine of 82.00%) the best results for body weight and feed conversion and at 0.8265% and 0.9339% (valine:lysine of 77.00% and 87.00%) the best back yield according to Duncan test. The isoleucine at 0.7729% (isoleucine:lysine of 72.00%) showed a improvement in feed conversion according to Duncan test (0.05%).

Page generated in 0.0759 seconds