Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 25 for “"laying hen"”.
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Systematic evaluation of laying hen exposure to atmospheric ammonia
… low atmospheric ammonia (NH3) concentrations in laying hen housing is a well-known challenge and recently has become the center of legislation for animal housing. In the winter months, poultry farm managers have to balance indoor temperature and environment (including atmospheric ammonia (NH3) …
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An investigation of laying hen interactions with ammoniated environments by means of preference testing
… interactions, and a laboratory study with hens in a controlled environment comprised this work. The main goal of this work was to evaluate laying hens’ perceptions regarding aerial ammonia (NH3). It is well known that NH3 is a predominant gas pollutant in commercial animal facilities, …
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AN INVESTIGATION OF POTENTIAL MECHANISMS UNDERLYING CHEMOSUPPRESSIVE EFFECTS OF DIETARY FLAXSEED IN THE LAYING HEN MODEL OF OVARIAN CANCER
… of specific symptoms during early disease. The laying hen is the only accessible animal model which develops epithelial ovarian cancer spontaneously, with features closely resembling the human disease. It has been estimated that approximately 30% of all cancers can be prevented with diet, …
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Dietary intervention with whole flaxseed or vitamin D has beneficial effects on leiomyomas in the oviduct of the laying hen
… and anti-fibrotic properties. Because the laying hen is the only animal to develop leiomyomas spontaneously as they age, they are an ideal animal model for the study of fibroids. Hen leiomyomas occur as polyps on the smooth muscle layer of the oviduct with increasing abundance as hens age …
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Effect of indomethacin (a prostaglandin inhibitor) on the ovulatory cycle, total plasma calcium, and egg shell thickness in the domestic laying hen (Gallus domesticus)
Thesis (M.S.)--Michigan State University. Dept. of Poultry Science,
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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
… 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 …
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Further Evaluation of the Available Phosphorus Requirement of Laying Hens and Methods for Improving the Availability of Phosphorus in Feedstuffs for Poultry
A final laying hen experiment was conducted to evaluate the efficacy of phytase for increasing amino acid utilization of three different laying hen diets. The results indicated that 300 units phytase/kg did not improve amino acid digestibility in laying hen diets containing corn, soybean meal, meat …
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Nutritional evaluation of canola meal produced from a new variety of canola seeds in broiler chickens and laying hens
… assays, two broiler chicken experiments and one laying hen experiment were conducted. The four precision-fed rooster assays were used to determine the values of MEn using conventional roosters and ileal digestible amino acid values using cecectomized roosters. The first experiment evaluated a …
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Evaluation of Feed Ingredients and Feed Additives on Poultry Performance and Health
… on their potential to improve turkey and laying hen health and performance. The second chapter is a literature review on ingredient particle size, Ca source, and varying feed additives. The third chapter determined that a smaller corn particle size (581 µm) was necessary for turkeys during …
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Molybdenum toxicity in the developing chick embryo
… order to determine the feasibility of using the laying hen as a source of molybdenum containing eggs, a dose response experiment was conducted which involved the feeding of graded levels of molybdenum to White Rock laying hens. The feeding of 2000 ppm of molybdenum resulted in decreases in egg …
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The Acute and Chronic Effects of a Cyclic Heat Stress on 24 to 28 Week Old Laying Hens on Performance, Egg Quality, Apparent Metabolizable Energy, and Blood Chemistry
Commercial laying hens are heavily selected for increased egg production, but little selection has occurred for resistance to extreme temperatures. The objective of the experiment was to determine the effects of a daily cyclic heat stress (HS) on performance, body temperature, egg quality, nitrogen …
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Behavior, welfare, production and bioenergetics of laying hens in alternative housing systems
… welfare, production, and bioenergetics of laying hens in alternative housing systems. It covers five experiments that were conducted in controlled environment and commercial settings with the following specific objectives: 1) Develop and validate a UHF RFID system able to evaluate nesting …
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Characterizing the role of dietary fat in the development and progression of liver dysfunction
… in mediating the metabolically healthy obese phenotype and to better characterizing the potential contribution of dietary fat and fatty acids as a therapeutic supplement to obesogenic diets. Specifically, flaxseed is high in α-linolenic acid (ALA; 18:3 n-3) and low in linoleic acid (LA; 18:2 …
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TALLOW FOR LAYING HENS
… and minimal amino acid utilization in the laying hen were studied in two experiments. In the first experiment diets contained six levels of animal tallow ranging from 0 to 10%. Percent egg production and egg mass were not significantly affected by tallow. Body weight was significantly …
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The complexity of infectious laryngotracheitis virus: a focus on vaccination and challenge viruses
… of ILTV in the trachea of chickens, which then can lead to ILT outbreaks.</p> <p>One of the regulations for ILT vaccines is that they must protect chickens against inoculation with an ILT challenge virus. All licensed vaccines in the U.S. are licensed by the United States Department of …
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Effect of amino acids and vitamin D3 on performance and biological responses in poultry
… and tryptophan requirement of small-framed laying hens and the lysine requirement of young broilers using empirical dose-response methods. The tryptophan requirement was estimated as 155.8 mg/d for egg mass, 153.2 mg/d for egg production and 140.4 mg/d for feed conversion ratio using a …
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Effects of Nutritional Manipulation on Poultry under Normal and Stressful Conditions
… was to investigate the tryptophan requirement of laying hens in peak production and the lysine and sulfur amino acid requirements of broiler chicks under a phase feeding scenario using different models. Digestible tryptophan requirements were estimated to be 137 for egg production, 133 for egg …
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Enriching Eggs of Laying Hens with Multiple Bioactive Nutrients for Improving Human Health
… studies by our group have demonstrated that laying hens are capable of enriching into their eggs health promoting compounds including a potent antioxidant astaxanthin (AST), the long chain omega-3 fatty acid docosahexaenoic acid (DHA), and the pre-activated form of vitamin D3 calcifediol. …
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Effects of feeding diets varying in nutrient density to Hy-Line W-36 laying hens on production performance and profitability
An experiment was conducted with 480 Hy-Line W-36 laying hens to determine whether feeding diets that varied in nutrient density would affect long-term egg production performance. At 18 wk of age, laying hens were weighed and randomly allocated to 6 replicate groups of 16 hens each (2 adjacent …
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