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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.
11

The Effects of a Single Strain Bacillus subtilis DFM on pullet performance, laying hen performance, and egg quality when fed from day of hatch until 70 weeks

Samper, Jordyn Marie 18 August 2022 (has links)
Direct-fed microbials (DFM) are a method to increase bird performance and health when antibiotics are removed or limited in the diet. The objective of this experiment was to determine the effects of a single strain Bacillus subtilis DFM on pullet performance, layer performance, and egg quality when fed from day of hatch until 70 weeks of age. In total, 576 Hy-Line W-36 laying hen pullets were randomly divided between two treatments (Control and DFM) on day of hatch across 12 cages for each of the treatments and maintained on those respective treatments for 70-weeks. The DFM was added at a target dose of 300,000 cfu/kg of feed. At the end of the 17-week pullet phase, DFM fed pullets resulted in reduced feed intake, improved FCRm with both similar body weights (P = 0.98) and body composition (P > 0.05) to the control fed pullets. At 17 weeks, 72 birds were randomly selected from each treatment and moved to 12 laying hen cages. At the end of the 52-week laying hen phase, DFM-fed hens had significantly higher hen-day egg production (P = 0.02), but decreased egg weights. No differences were reported in egg mass or feed intake, but FCR was significantly improved (P = 0.02) on a per dozen eggs basis, and improved (P = 0.06) on a g/g basis by 7.1 points with DFM-fed hens having an FCR of 2.016 and control fed hens having and FCR of 2.087. Supplementation of diets with DFM resulted in a trend in egg specific gravity, but no differences were reported in shell breaking strength or shell weight. Overall, supplementation of the DFM lowered feed intake and improved FCR without affecting body composition in the pullet phase, and increased production and improved FCR during the egg laying phase. / Master of Science / Due to the decreased use of antibiotics across the poultry industry, producers and allied companies are developing new methods to increase bird health and performance when antibiotics are removed from or limited in the diet. One such method is through the use of "good" bacteria or technically called Direct-Fed Microbials (DFM). Direct-fed microbials are defined as live microorganisms that when fed, confer a health benefit to the host. The goals of this thesis were to determine the effects of a Bacillus subtilis based DFM on pullet performance, laying hen performance, and egg quality when fed from day of hatch until 70 weeks of age. In the pullet phase, DFM-fed pullets had reduced feed intake and improved feed conversion ratio (the ratio of feed intake to body weight gain), with no differences in body weights or body composition at the end of the 17-week growth period. In the laying phase, DFM fed hens had significantly improved egg production, but lighter eggs compared to the control fed hens. Addition of the DFM significantly improved feed conversion ratio per dozen eggs by 5.3 points and reduced feed conversion ratio on a g/g basis by 7.1 points in the 52-week laying phase. Small improvements were noted in specific gravity, but no differences were reported in shell weight or shell breaking strength. When fed from day of hatch until 70 weeks of age, the Bacillus subtilis DFM allowed the pullets to reduce their feed intake, but maintain body development for egg production resulting in an improved feed conversion ratio (FCR) in the growth phase before egg production and once hens initiated egg production resulted in smaller eggs, but increased egg production and FCR in laying hens with minimal differences in egg quality. Therefore, the DFM may be able to be used in place of growth promoting antibiotics to help support efficient protein production.
12

A critical appraissal of the home-based food security projects with reference to layers at Makhuduthamaga Sekhukhune District in Limpopo Province

Monyela, Mante Thabitha Daisy January 2007 (has links)
Thesis (M.Sc) (Agriculture) --University of Limpopo, 2007. / It is beyond doubt that a large proportion of the population in the rural areas are experiencing great difficulty in securing adequate food in both amount and quality. Poverty alleviation programs are embarked in various countries with Makhuduthamaga being no exception. The study was designed to evaluate the home-based egg production projects. The study was conducted at Makhuduthamaga sub- District of Sekhukhune District of Limpopo province. Two instruments were used for data collection namely Delphi technique and two structured questionnaires. The Delphi technique was used for both the beneficiaries and the extension officers to identify, list and rank in order of importance the constraints which impacted negatively on egg production as well as the actions taken to address those constraints. Two separate questionnaires were also used to collect data from both the beneficiaries and the extension officers. Out of twenty villages a list of 231 beneficiaries of starter up packs was identified. Krecjcie and Morgan (1970) sample estimation required 144 randomly selected beneficiaries of starter up packs to participate in the study which reflected 0.6 margin of error. The two questionnaires with open ended and closed ended questions were piloted at Fetakgomo District in four villages with thirty one beneficiaries and ten extension officers. Reliability was found to be 0.81 skills, 0.80 for support from extension officers and 0.61 for government expectations. The Statistical Package for the Social Sciences was used for the entering data collected. Descriptive statistics were used to analyse data. The findings revealed that the majority of the beneficiaries fall within the prescribed selection criteria. Almost all except one village were given the starter up packs namely 18 layers, four bags of laying mash, cage, nipples, feeding trays and a cage as outlined in the policy. Training was considered by both the beneficiaries and the extension officers as inadequate for effective and efficient running of the home based egg production projects. The results revealed that the majority of beneficiaries did not meet government expectations. An acknowledgement was made that during the implementation of projects mistakes were committed by both beneficiaries and extension officers. Analysis of variance was also used to determine the relationship between the level of education and the extent to which government expectations were met. There was no significant relationship between skills such as technical, management, financial, administration and the extent to which government expectations were met. However there was a significant relation between marketing skills and levels of education. The majority of beneficiaries had a low level of education. Pearson correlation coefficient was used to determine whether there is a relationship between skills and support from the extension officers and the extent to which government expectation were met. Skills such as technical and marketing as well as the support from the extension officers attributed much to variations with regard to the extent to which government expectation were met. Constraints were also encountered which impacted negatively on egg production. Extension officers identified the following constraints such as survey not done prior to distribution, insufficient human resources, training, insufficient monitoring, inadequate transport, inability of beneficiaries to purchase feed, inadequate starter packs and failure to establish cooperatives. Beneficiaries identified constraints such as feed, training, diseases and unavailability of veterinarian, mortality of layers on arrival, theft and predation, inadequate starter packs, layers not of the same age and cages that are too small. Out the constraints mentioned only three namely insufficient transport, inadequate starter up packs `and one aspect on feed i.e. soft shelled eggs were addressed. Although the majority of beneficiaries considered home based egg production projects inadequate in providing access to adequate food, slightly over half of them favoured them as future household projects. / Kellog Foundation
13

The Cost of Producing Eggs in Utah, 1946

Allred, Chall 01 May 1947 (has links)
The production of poultry and poultry products is one of Utah's major agricultural industries. In 1945, 22 percent of the farm income in Utah was derived from poultry and poultry products. About 10 percent of the total farm income was from eggs.
14

The effects of chronic exposure to environmentally relevant levels of water-borne cadmium on reproduction in fathead minnows

2013 October 1900 (has links)
Cadmium (Cd) is a priority pollutant in ecosystems worldwide. It is highly toxic to aquatic organisms including fish at fairly low concentrations. Numerous studies have investigated the influence of Cd exposure on fish, but few of them have considered how environmentally relevant levels of Cd affect reproduction, particularly reproductive behaviour. To assess the toxicity of Cd on fish reproduction, breeding fathead minnows (Pimephales promelas) were exposed to water-borne Cd for 21 days at four different concentrations (0, 1, 2.5 and 5 µg/L, respectively) based on a standard short-term reproductive assay and reproductive performance as well as behaviour were examined during or at the end of the exposure period. The results showed that Cd accumulated in a dose-dependent manner in the livers and ovaries of female fish. Brood size and mean egg production were significantly reduced in Cd-exposure treatment groups. When fertilized eggs were incubated in the water containing 2.5 µg/L or higher Cd, there was delayed hatching, but at the same time there was greater synchronous hatching after hatching started. Hatching success of Cd-exposed eggs also declined compared to the control. No significant difference was observed among treatments in adult fish survival, the number of breeding attempts, fertilization success, egg size, plasma β-estradiol levels of female, larval deformities, reproductive behaviour, gonadosomatic index or liver somatic index. The results of this study demonstrate that Cd is able to impair reproduction of fathead minnow at the concentration as low as 0.64 µg/L. It is harmful to both breeding fish and their offspring. The traditional endpoints used in standard reproduction assay (e.g. egg production and brood size) are probably more sensitive than behavioural endpoints, but the traditional method of interpreting reproductive impairment may underestimate toxic effects. The findings of this study have important implications for understanding the effects of chronic Cd exposure in metal-impacted feral fish populations. It can be applied to the protection or restoration of fish populations in Cd contaminated aquatic systems.
15

Miljöpåverkan av äggproduktion : En jämförelse mellan Lilluns ägg och andra svenska äggproducenter

Edin, Malin January 2015 (has links)
The purpose of this report was to compare Lilluns egg production with other Swedish egg producers based on the flow of nutrients (nitrogen, phosphorus and potassium) in the egg production systems. The main focus in the report was the utilization rate of the forage and the excess of nutrients per kg egg. Additionally, the purpose was to identify the environmental impact from Lilluns egg production and compare the results with other egg producers. The inflow of nutrients associated with forage and poultry was compared with the nutrients that were exported from the production. All of the egg producers in this study had an excess of nutrients. The utilization rate of the forage for Lilluns egg was 47 %, the other egg producers in this study had an utilization rate between 45-50 %. The results showed that Lilluns egg had an excess of nitrogen of 0,04 kg/kg eggs. Lilluns egg also had an excess of phosphorus and potassium. The excess of phosphorus was 0,01 kg/kg eggs and 0,013 kg/kg eggs for potassium. The results showed that all the egg producers in this study had an excess of all the nutrients. The conclusion is that the egg production systems in this study have a similar utilization rate and the excess of nutrients per kg egg was also similar for all the egg producers.
16

Laying hens in furnished cages : use of facilities, exterior egg quality and bird health /

Wall, Helena. January 2003 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003.
17

Effects of Time Specific F-Strain Mycoplasma Gallisepticum Inoculation Overlays on Pre-Lay Ts-11-Strain Mycoplasma Gallisepticum Inoculation on Performance, Egg, Blood, and Visceral Characteristics of Commercial Egg Laying Hens

Vance, Elizabeth Anne Middleton 15 December 2007 (has links)
Vaccination programs using live whole cell vaccines are presently being used to control outbreaks and to help protect flocks from field strains of Mycoplasma gallisepticum. The primary goal of the present study was to investigate the effects of a ts11-strain M. gallisepticum inoculation alone, and in conjunction with F-strain M. gallisepticum overlays at 22 or 45 weeks of age during lay. In this study, it was shown that a pre-lay ts11 vaccination had a broad range effect on the physiology of the commercial layer without affecting overall performance. The timing of an overlay vaccination using F-strain M. gallisepticum during lay also had varied effects on physiological parameters without affecting overall performance. This study indicates that using ts-11-strain M. gallisepticum in conjunction with F-strain M. gallisepticum does not negatively affect laying hen performance. Furthermore, this inoculation combination offers benefits above the use of those achieved through either inoculation alone
18

Effect of synbiotic and organic acid plus phytochemical product supplementation on layer production performance and immune parameters

Luoma, Amanda Elaine 07 October 2016 (has links)
No description available.
19

Sustainable Development in egg production : Perceived key challenges farmers face in Germany

Hernandes, Emilie January 2016 (has links)
The subject matter of this paper is a comparative review of egg production systems for theircontribution to sustainable development of egg production in order to assess the perceived challenges of eggfarmers in Germany. The thesis features a case study which presents two farms located in Germany, andimplementing different farming methods. The floor-range farming method and the organic system illustrate thisexample. The methodological approach is based on a three-phase framework, in which significant issuesconcerning sustainable development are presented (Phase 1), the significant issues are translated into sustainableindicators (Phase 2), and the contribution of sustainable indicators to sustainable development is assessed (Phase3). Phase 1 and 2 build on an extensive literature review and farmers consultation. Phase 3 relies on numericalcomparisons. A comparative analysis of the empirical data is based on theories and the developed conceptualframework. Based on the comparison of two specific farms, the results of this work indicate that the organicfarming system reveals the least negative contribution to sustainable development of egg production in Germany.The floor-range farming system shows a slightly more negative contribution to sustainable developmentcompared with the organic EPS. The organic farming system, therefore, is considered the better animal-friendlysystem. It is certainly noteworthy to mention that the organic system however fail to contribute to sustainabledevelopment from an economic perspective. Thus, the main perceived challenge for the organic farmer is tooperate his organic business in a more profitable way. The floor-range system on the other hand, succeeds tocontribute to sustainable development in economic terms, but fails to contribute positively from an ecologicaland social perspective. Therefore, the farmer operating the floor-range EPS needs to improve the ecological aswell as social conditions on his farm in order to achieve an equal positive contribution to sustainabledevelopment.
20

Iluminação para poedeiras comerciais

Ouros, Caio César dos. January 2019 (has links)
Orientador: Edivaldo Antonio Garcia / Resumo: Com o objetivo de atualizar as informações relacionadas ao fornecimento de luz para as poedeiras comerciais modernas visando racionalizar o uso da energia elétrica nos sistemas de produção de ovos com manutenção ou melhoria do desempenho produtivo e qualidade dos ovos, foram realizados três experimentos. Em cada experimento foram utilizadas 480 aves da linhagem Lohmann LSL® distribuídas em delineamento em blocos casualizados com quatro tratamentos e seis repetições de 20 aves cada. O experimento I foi realizado para avaliação do efeito do comprimento do fotoperíodo sendo: fotoperíodo 1 - 14 horas de luz e 10 horas de escuro (14L:10E); fotoperíodo 2 – 15 horas de luz e 9 horas de escuro (15L:9E); fotoperíodo 3 – 16 horas de luz e 8 horas de escuro (16L:8E); fotoperíodo 4 – 17 horas de luz e 7 horas de escuro (17L:7E). No experimento II foram testadas quatro iluminâncias: T1 – 5 lux; T2 – 10 lux; T3 – 15 lux; T4 – 20 lux. O fotoperíodo adotado foi o de 14L:10E que proporcionou o melhor resultado no experimento I. O experimento III foi realizado para avaliação de quatro programas de luz: contínuo (controle) – consistiu de um fotoperído único; intermitente 1 – consistiu no fornecimento de 1 hora de luz, uma hora antes do início fotoperíodo natural (manhã); intermitente 2 – consistiu no fornecimento de 30 minutos de luz, uma hora antes do início do fotoperiodo natural; intermitente 3 – consistiu no fornecimento de 15 minutos de luz, uma hora antes do início do fotoperíodo natural.... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

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