• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Descrição do Crescimento do Corpo e Principais Componentes de Aves de Postura / Description of growth of the main body components of pullets

Alves, Warley Junior 22 February 2018 (has links)
Submitted by WARLEY JUNIOR ALVES null (warleyjunioralves@hotmail.com) on 2018-02-28T00:23:50Z No. of bitstreams: 1 Dissertação Warley Júnior Alves_com certificado.pdf: 3853155 bytes, checksum: ac4674ee80875ac89692e21cc0a679b7 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-02-28T13:12:32Z (GMT) No. of bitstreams: 1 alves_wj_me_jabo.pdf: 3853155 bytes, checksum: ac4674ee80875ac89692e21cc0a679b7 (MD5) / Made available in DSpace on 2018-02-28T13:12:32Z (GMT). No. of bitstreams: 1 alves_wj_me_jabo.pdf: 3853155 bytes, checksum: ac4674ee80875ac89692e21cc0a679b7 (MD5) Previous issue date: 2018-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A eficácia de um programa nutricional depende do conhecimento a respeito do potencial genético de crescimento da ave, por ser esta a forma racional de calcular as exigências nutricionais e predizer o consumo de alimento. Neste sentido, os modelos fatoriais integrados as curvas de crescimento de aves auxilia no estabelecimento ou avaliação de programas alimentares específicos. Por serem modelos dinâmicos, possibilitam calcular a ingestão de acordo com o padrão de crescimento da linhagem ao longo do tempo. Tradicionalmente, a avaliação da composição corporal é feita por abate comparativo que impossibilita o acesso rápido às informações e inviabiliza o estudo das variações das caraterísticas estudadas no decorrer do tempo no mesmo animal. Uma alternativa é a técnica de absorciometria por duplo feixe de raios-X (DXA) que permite avaliar in vivo a composição corporal das aves em tempo real sem a necessidade de sacrifica-la, conciliando interesses sociais e científicos. Com base nisso, objetivou-se neste trabalho descrever o potencial de crescimento do corpo e componentes corporais de poedeiras Dekalb e Lohmann (White e Brown) meio da função Gompertz, com a composição corporal tomado pela técnica DXA nas mesmas aves no decorrer do crescimento. Foram utilizadas 360 poedeiras das linhagens Lohmann e Dekalb distribuídas em delineamento inteiramente ao acaso, com quatro tratamentos (linhagens) e seis repetições com 15 aves. As aves foram alojadas em galpão experimental dotado de gaiolas em sistema piramidal, controle de temperatura automatizado, comedouro tipo calha e bebedouro nipple. O programa alimentar adotado foi ad libitum composto por cinco dietas segundo a idade formuladas de forma a atender as exigências nutricionais das linhagens, garantindo que não houvesse nenhum nutriente limitante. Para descrição do crescimento uma ave por unidade experimental foi tomada aleatoriamente, identificada, e avaliadas do 1º ao 126º dia de idade, nas idades 1, 14, 28, 56, 70, 77, 84, 98, 112 e 126 dias, foram escaneadas para estimar o conteúdo mineral ósseo, tecido magro e gordo, por meio da absorciometria por duplo feixe de Raios X (DXA), usando modelo Hologic-QDR®. Concomitantemente, fez-se um estudo para relacionar dados de composição obtidos pelo DXA e por análise química do corpo livre de penas (CLP), Esses dados foram submetidos à análise de variância (ANOVA), sendo constatadas diferenças na quantificação da composição corporal pelas diferentes técnicas. Devido à essas diferenças, foram ajustadas regressões para cada componente químico do corpo, assim foram gerados equações de correção dos dados obtidos pelo DXA em referencia ao método químico, usando para isso aves Dekalb Brown, seguindo as mesmas idades e procedimentos do estudo de crescimento. A função Gompertz foi utilizada para descrever o crescimento do corpo e componentes químicos para cada linhagem. A mensuração da composição corporal nas mesmas aves ao longo do tempo pelo DXA auxiliou na redução do erro na avaliação do crescimento de poedeiras. As linhagens avaliadas neste estudo apresentaram diferenças no crescimento do corpo, penas e componentes entre se. E os parâmetros de crescimento aqui descritos condizem com os encontrados na literatura, e auxiliará no aperfeiçoamento de modelos de calculo de exigências nutricionais, melhorando a eficácia de programas alimentares. / The efficacy of a nutritional program depends on knowledge about the bird's genetic potential for growth, since this is the rational way of calculating nutritional requirements and predicting food consumption. In this sense, the factorial models integrated the growth curves of birds assists in the establishment or evaluation of specific food programs. Because they are dynamic models, they make it possible to calculate the feed intake according to the growth pattern of the lineage over time. Traditionally the evaluation of the body composition is made by comparative slaughter, impossibility the quick access to the information and to study the variations of the characteristics studied in the course of time in the same animal. An alternative is the X-ray absorptiometry technique (DXA) that allows in vivo evaluation of the body composition of the birds without the need to sacrifice them reconciling social and scientific interests. Based on this, the objective of this work was to describe the growth potential of the body and body components of laying hens Dekalb and Lohmann (White and Brown) through of the Gompertz function, with the body composition taken by the DXA technique in the same birds during the growth. A total of 360 laying hens of the Lohmann and Dekalb strains were used in a completely randomized design, with four treatments (strains) and six replicates of 15 birds. The birds were housed in experimental shed with cages in pyramidal system and with automated temperature control. Diets were provides ad libitum and composed of five diets according to age formulated to meet the nutritional requirements of the strains, ensuring that there was no limiting nutrient. To describe the growth, one bird per experimental unit was randomly identified and evaluated from 1 to 126 days of age. In the ages 0, 14, 28, 56, 70, 77, 84, 98, 112 and 126 days, birds were scanned to estimate bone mineral content, lean and fat tissue by means of dual beam X-ray absorptiometry (DXA) using Hologic-QDR® model. At the same time, a study was performed to correlate composition data obtained by DXA and by chemical analysis of the feather free body (FFB). These data were submitted to analysis of variance (ANOVA), being verified differences in the quantification of the body composition by the different techniques. Due to these differences, regressions were adjusted for each chemical component of the body, thus generating correction equations of the data obtained by DXA in reference to the chemical method, using Dekalb Brown birds, following the same ages and procedures of the growth study. The Gompertz function was used to describe the growth of the body and chemical components for each strain. The measurement of body composition in the same birds over time by DXA assisted in the reduction of error in the evaluation of the growth of laying hens. The strains evaluated in this study showed differences in body growth, feathers and components among themselves. And the growth parameters described here are consistent with those found in the literature, and will aid in the improvement of models for calculating nutritional requirements, improving the effectiveness of feeding programs.
2

Stanovení mastných kyselin ve vejcích v závislosti na druhu krmení u nosných slepic

Losertová, Milena January 2018 (has links)
The aim of the diploma thesis was to monitor the influence of grass in feed on fatty acid content in eggs. The experiment was carried out on Lohmann Brown Classic hybrids at the age of 12 weeks. Layers were divided into five groups. The feed was enriched by a 5% drop of Trifolium pretense, Trifolium repens, Medicago sativa and Lolium perenne. The control group were fed in a diet containing color-promoting additives. The fattening took three months. Egg samples were collected at the end of the month. Feedin and the power was run ad libitum. The effect of the addition of dried plants was significantly (P < 0,05) to the color of the yolk. A statistically significant (P < 0,05) incerease in palmitic acid in eggs was recorded during the experiment in eggs produced by laying hens which were in diet containing addition of Trifolium pretense and Medicago sativa. A demonstrable increase (P < 0,05) was also observed in laying hens which were fed with a mixture enriched with Trifolium pretense in percent α-linolenic acid content.
3

Untersuchung zur Gestaltung von Zuchtprogrammen in der Legehennenzucht / Studies on the design of breeding programs in the breeding of laying hens

Tsehay, Fitsum 19 May 2005 (has links)
No description available.
4

Comparison of productivity and economic benefit of commercial Lohmann Brown Lite layer’s on free-range and conventional cage systems

Maboneng, Kgaditsi 06 1900 (has links)
Text in English / The study was conducted in two different types of natural ventilated housing systems; one featured with conventional laying cages while other had free-range system features. The aim was to analyse productivity and economic benefit or loss of the Lohmann Brown Lite on different housing (Free-range system and Conventional cage system) with an evaluation of production cost. The total of 49 700 point of lay Lohmann Brown Lite layers pullets were placed in four natural ventilation free-range houses each consist of three rows of two tier conventional laying cages. The other 40 000 point of lay Lohmann Brown Lite layers pullets were place in four free-range houses each with placement of 10 000 chickens. The Cobb Douglas production model was used to determine the productivity of two different housing system by factoring the fixed cost and variable cost of the entire production process. The breakeven point tool was used to analyse the point where the total revenue equals the total variable and fixed expenses and the cost volume profit by measuring the profitability of each housing system (Nabil et al. 2014). The results of the study revealed different productivity between conventional cage system (82.94%) and the free-range system (77.46%). These results led to the acceptance of hypothesis 1 that “the production of Lohmann Brown Lite is the same when they are kept on the free-range system or conventional cage system. The capital investment and operation on conventional cage system showed breakeven at 43 months while free-range system showed breakeven at 60 months. The economic benefit analysis shows that the free-range system has cost benefit of R0.29 and conventional cage system has a cost benefit of R0.26. It means for every rand spent, farmer may get R0.29 Rand as profit for free-range system and every rand spent for conventional cage system can get R0.26 Rand. The economic benefit to farmer is greater on free-range system that lead to acceptance of hypothesis 2 that the economic benefit of egg production is greater on the free-range system compared to conventional cage system. Free-range housing system remain the best alternative to replace the conventional cage housing system. / Agriculture and  Animal Health / M.Sc. (Agriculture)

Page generated in 0.0332 seconds