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  • 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.
1

Role of insulin-like growth factors and type I receptors in the developing porcine intestine

Morgan, Catherine J. January 1995 (has links)
The role of the IGF system during intestinal development of the pig, and in particular the significance of dietary IGF-I was investigated. Significant concentrations of IGF-I and IGFBP were measured in milk and colostrum and in vitro immunoaffinity chromatography studies confirmed IGF-I stability in the presence of newborn and suckled intestinal contents. Specific IGF-I receptors were identified on apical and basolateral membranes, and the cytoplasm of villus/crypt enterocytes. Receptor binding data revealed binding to a single site, with an affinity of 1nM. Receptor affinity remained constant during development but in apical microvillar membranes, IGF-I receptors were transiently up-regulated in suckled animals. The specificity of receptors was confirmed using competition binding and affinity crosslinking studies, and the functional activity of receptors demonstrated using an in vitro receptor autophosphorylation assay. In Caco-2 intestinal cells IGF-I binding and IGF-I receptor mRNA expression was significantly increased in the presence of 7 and 14 day milk, suggesting that milk-borne factors may regulate the up-regulation observed in vivo. In vivo experiments were undertaken using colostrum-fed and colostrum-deprived artificially-reared pigs. Significant differences in plasma IGF-I and IGF binding proteins were observed in the IGF- treated animals compared to controls suggesting that IGF-I remained bioactive in the intestine and was transported to the circulation. The in vivo effects of IGF-I were modulated by early nutrition. Plasma IGF-I increased in colostrum-deprived animals, whereas in colostrum-fed animals levels decreased.
2

The Effects of Different Feeding Program and Inclusion of Glycerol, Glucose or Sucrose in Broiler Starter Diets on Growth Performance and Intestinal Development

Wang, Anhao 20 March 2014 (has links)
The easily utilized energy sources, glycerol, glucose and sucrose were used in broiler starter diets to improve growth performance. Trials investigated the effects of inclusion of easily utilized energy sources (EUES) on broiler duodenum and ileum histological developments. The effects of EUES on CHICKS delayed access to feed were investigated. In trial one, newly hatched chicks were randomly assigned to immediate (IA) or 36 hours delayed access to feed and water (DA) and fed 4 or 8% EUES during first 14 days post hatch. In trial two, males and female chicks were randomly assigned to IA or 48 hours DA, and fed 8% glycerol or glucose diets for a 14 days period. In both trials growth performance, duodenum and ileum developments were affected by dietary treatments. In conclusion, glycerol can be added into broiler starter diets up to 8%.
3

Desempenho, qualidade de ovos e parâmetros intestinais de poedeiras leves alimentadas com rações contendo butirato de sódio protegido / Performance, eggs quality and parameters intestinals of laying hens fed with diet with butyrate sodium protected

Pires, Marília Ferreira 20 April 2016 (has links)
Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-06-21T17:17:58Z No. of bitstreams: 2 Dissertação - Marília Ferreira Pires - 2016.pdf: 2038317 bytes, checksum: 6bf59849e1b382d63908376fa0df3f69 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Cláudia Bueno (claudiamoura18@gmail.com) on 2017-07-07T19:53:05Z (GMT) No. of bitstreams: 2 Dissertação - Marília Ferreira Pires - 2016.pdf: 2038317 bytes, checksum: 6bf59849e1b382d63908376fa0df3f69 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-07T19:53:05Z (GMT). No. of bitstreams: 2 Dissertação - Marília Ferreira Pires - 2016.pdf: 2038317 bytes, checksum: 6bf59849e1b382d63908376fa0df3f69 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-04-20 / The objective of the present study was to evaluate the effect of adding increasing levels of protected sodium butyrate in the diet of laying hens from 61 weeks of age on performance, egg quality and intestinal parameters. The treatments were 0, 105, 210 and 300 g / t of sodium butyrate protected in the feed. To evaluate the performance and quality of eggs, 320 laying hens were used as Dekalb Whyte lineage (61-76 weeks old) in cages and distributed design in blocks (with the weight of the blocky birds), with four treatments and eight replicates of 10 birds. The experiment was 16 weeks divided into four periods of 28 days each. The 76 weeks of age were separated 48 birds for metabolism trial with four treatments and six replicates of two birds. At the end of the assay was sacrificed a repeat per bird for intestinal development analysis. Was conducted analysis of variance and polynomial regression of the data with the help of the statistical program R. Regarding the performance for the period 73-76 weeks of age was negative linear effect for feed conversion (kg feed / kg eggs). For quality variables eggs were observed increasing linear effect for shell thickness in the periods 61-64 and 65-68 weeks and during the periods 69-72 and 73-76 weeks were observed quadratic effect with maximum point 199 and 174 g / t sodium butyrate protected, respectively. For specific gravity quadratic effect was found with a maximum point at 177 g / t sodium butyrate protected only in the period 73-76 weeks. To the percentage of peeling was found quadratic effect on periods 69-72 and 73 to 76 weeks, with a maximum at point 89 and 172 g / t sodium butyrate protected, respectively. To yolk index found a quadratic effect in the period 69-72 weeks of age with a minimum point at 189 g / t of protected sodium butyrate. When evaluating albume index, found a negative linear effect in the period 69-72 weeks of age. For Haugh unit regression was effective only in the period 65-68 weeks with a quadratic effect, with maximum point at 142 g / t of sodium butyrate. In total period was observed quadratic effect for shell thickness, percentage of peel and breakage resistance, in which maximum points were found in 193; 136 and 198 g / t sodium butyrate protected, respectively. When evaluating yolk index in the total period, found a quadratic effect with minimum point at 181 g / t. For intestinal development variables it was found negative linear effect for the length of the jejunum. For height of villi, it found a linear increase in the duodenum and jejunum. For crypt depth, quadratic effect was found in the jejunum with a minimum point at 151 g / t sodium butyrate protected. For the variable villous / crypt ratio was found linear increase in the duodenum and jejunum, and the ileum quadratic effect, with maximum point at 171 g / t. For BN was found quadratic effect with maximum point at 93 g / t, and for BEE was found increasing linear effect. For EMA and EMAn variables were found increasing linear effect. The addition of protected sodium butyrate in laying hens diet did not influence the performance of the birds, but improved the quality of skin and intestinal parameters (intestinal development and metabolization of nutrients). It is recommended to improve the quality of shell eggs in layers in the final production phase, the level of 150 g / t sodium butyrate protected. For intestinal development and diet metabolizable energy level of 300 g / t of sodium butyrate protected. / Objetivou-se com o presente estudo avaliar o efeito da adição de níveis crescentes de butirato de sódio protegido na ração de poedeiras comerciais, a partir de 61 semanas de idade, sobre o desempenho, qualidade de ovos e parâmetros intestinais. Os tratamentos foram: 0, 105, 210 e 300 g/t de butirato de sódio protegido na ração. Para avaliação do desempenho e qualidade de ovos, foram utilizadas 320 poedeiras comerciais da linhagem Dekalb Whyte (61 a 76 semanas de idade) alojadas em gaiolas e distribuídas em delineamento em blocos ao acaso (sendo o peso das aves blocado), com quatro tratamentos e oito repetições de 10 aves. O experimento teve duração de 16 semanas divididas em quatro períodos de 28 dias cada. As 76 semanas de idade foram separadas 48 aves para o ensaio metabólico, com quatro tratamentos e seis repetições de duas aves. Ao final do ensaio metabólico foi sacrificada uma ave por repetição para análise de desenvolvimento intestinal. Foi realizado análise de variância e regressão polinomial dos dados com auxílio do programa estatístico R. Com relação ao desempenho, para o período de 73 a 76 semanas de idade houve efeito linear negativo para conversão alimentar (kg ração/kg de ovos). Para as variáveis de qualidade de ovos foram observados efeito linear crescente para espessura da casca nos períodos de 61 a 64 e 65 a 68 semanas, e nos períodos de 69 a 72 e 73 a 76 semanas foram observados efeito quadrático com ponto de máxima em 199 e 174 g/t de butirato de sódio protegido, respectivamente. Para gravidade específica foi encontrado efeito quadrático com ponto de máxima em 177 g/t de butirato de sódio protegido apenas no período de 73 a 76 semanas. Para a porcentagem de casca foi encontrado efeito quadrático nos períodos de 69 a 72 e 73 a 76 semanas, com ponto de máxima em 89 e 172 g/t de butirato de sódio protegido, respectivamente. Para índice de gema encontrou-se efeito quadrático no período de 69 a 72 semanas de idade com ponto de mínima em 189 g/t de butirato de sódio protegido. Ao avaliar índice de albúmen, encontrou-se efeito linear negativo no período de 69 a 72 semanas de idade. Para unidade Haugh houve efeito de regressão apenas no período de 65 a 68 semanas com efeito quadrático, apresentando ponto de máxima em 142 g/t de butirato de sódio. No período total foi observado efeito quadrático para espessura de casca, porcentagem de casca e resistência à quebra, nos quais foram encontrados pontos de máxima em 193; 136 e 198 g/t de butirato de sódio protegido, respectivamente. Ao avaliar índice de gema no período total, encontrou-se efeito quadrático com ponto de mínima em 181 g/t. Para as variáveis de desenvolvimento intestinal, foi encontrado efeito linear negativo para comprimento do jejuno. Para altura de vilos, foi encontrado efeito linear crescente no duodeno e jejuno. Para profundidade de criptas, foi encontrado efeito quadrático no jejuno, com ponto de mínima em 151 g/t de butirato de sódio protegido. Para a variável relação vilo/cripta, foi encontrado efeito linear crescente no duodeno e jejuno, e efeito quadrático no íleo, com ponto de máxima em 171 g/t. Para BN foi encontrado efeito quadrático com ponto de máxima em 93 g/t, e para BEE foi encontrado efeito linear crescente. Para as variáveis EMA e EMAn foram encontrados efeito linear crescente. A adição de butirato de sódio protegido na dieta de poedeiras comerciais não influenciou no desempenho das aves, mas melhorou a qualidade de casca e os parâmetros intestinais (desenvolvimento intestinal e metabolizabilidade de nutrientes). Recomenda-se, para melhorar a qualidade de casca de ovos em poedeiras na fase final de produção, o nível de 150 g/t de butirato de sódio protegido. Para desenvolvimento intestinal e metabolizabilidade da energia da dieta o nível de 300 g/t do butirato de sódio protegido.

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