Life Sciences Commons^™

Autophagy And Its Potential Role In Stress And Feed Efficiency Using Avian Lines, Alissa Laura Piekarski

Graduate Theses and Dissertations

Autophagy is a highly conserved cellular mechanism that is responsible for the degradation and recycling of damaged organelles. Recently, autophagy has been involved in critical roles during overall development of the organism and degradation of damaged cellular components. This pathway has witnessed dramatic growth in the last few years and has been extensively studied in yeast and mammals, however, there is a paucity of information in avian (non-mammalian) species. First, we characterized genes involved in the autophagy pathway in male and female Jungle Fowl to determine gender and tissue specific differences. Secondly, tissue and genotype differences in Japanese quail selected …

Reduction Of Campylobacter Jejuni On Chicken Wingettes By Treatment With Caprylic Acid, Chitosan Or Protective Cultures Of Lactobacillus Spp., Ann Nicole Woo-Ming

Graduate Theses and Dissertations

Poultry is one of the main sources of protein in the United States and in 2014 Americans ate approximately 100 lbs per person. However, consumption of poultry products is strongly associated with foodborne illness from Campylobacter. In the first study, chitosan, caprylic acid and their combination were evaluated as a coating treatment for the reduction of Campylobacter jejuni on poultry products. For the initial screening trials, chitosan of three different molecular weights (15-50 kDa, 190-310 kDa and 400-600 kDa) was evaluated at three concentrations (0.5%, 1.0%, 2.0%) and separately, caprylic acid was tested at 0.5%, 1.0% and 2.0% using chicken …

Leptin Regulates The Expression Of Autophagy-Related Genes In Chickens, Peter Olawale Ishola

Graduate Theses and Dissertations

Autophagy or cellular self-digestion, a lysosomal degradation pathway that is conserved from yeast to human, plays a key role in recycling cellular constituents, including damaged organelles. It also plays a pivotal role in the adaptation of cells to a plethora of distinct stressors including starvation. Autophagy has been extensively studied in mammals and yeast, but little is known in avian species. Thus, the major objective of the present study was to determine the effects of leptin on autophagy-related genes in chicken hypothalamus, muscle and liver. Leptin is an adipocytokine that is mostly produced by white adipose cells in mammals (as …

Transcriptomics Of Chicken Primordial Germ Cells, Nhung Thi Nguyen

Graduate Theses and Dissertations

Chicken primordial germ cells (PGCs) are derived from extraembryonic tissue of the embryo and first appear at stage X of development. They enter the bloodstream and migrate to the genital ridge, unite with somatic tissue to form a developing gonad, and then differentiate to sperm or ova (Fujimoto et al., 1976). Understanding molecular features of both male and female PGCs not only clarify the differentiation mechanism of such cells toward different germ lines, but will also help in selecting for highly productive types of commercial chicken. Most previous studies focused on the location of PGCs (Eyal-Giladi et al., 1981; Swift …

Broiler Breeder Mating Behavior And The Effects Of Pre-Incubation Embryo Integrity Modifications On Broiler Performance, Emily Kathryn Lhamon

Graduate Theses and Dissertations

Modern broiler breeders have been observed displaying significantly less mating behaviors than their ancestral fowl. Effective mating behavior translates into fertile hatching eggs that ultimately become broilers processed for market. The poultry industry has made significant changes in genetics, environment, housing, and diets of commercial poultry. However, there are some concessions made in genetic selection and streamlined management to produce larger, fast-growing, efficient birds. Aggression in broiler breeder males is believed to be a sign of high fertility. However, highly aggressive males pose a threat to the welfare of their flock mates, and may also impede frequency of mating and …

In Vivo Periodical Monitoring Of Immune Cell Infiltration In Response To Feathers And Intramuscular Injection Of Ionps Using The Pulp (Dermis) Of Growing Feathers As Test Site Tissue In Chickens, Olfat Taleb Alaamri

Graduate Theses and Dissertations

The applications of nanoparticles are growing, but little is known about their interactions with the immune system as most studies did not use suitable in vivo test systems. The purpose of these studies was to investigate the utility of chicken growing feathers as an in vivo test site for iron oxide nanoparticle (IONP) interactions with the immune system. The first objective of this study was to monitor leukocyte infiltration into the growing feather pulp upon the administration of IONP and IO-mIgG preparations. The second objective was to test the utility of IONPs as vaccine adjuvants by monitoring primary and memory …

Evaluation Of Bacillus Spp Candidates For Aflatoxin B1 Biodegradation In Broiler Chickens, Rosario Galarza Seeber

Graduate Theses and Dissertations

Poultry health has been traditionally maintained by hygenic measures, vaccinations, and the use of antibiotics. Modern husbandry management considers the use of probiotics as a natural way to protect birds against many everyday pathogens. Different strains of Bacillus spp. have proved to have beneficial effects in poultry production. However, the most used bacterium in commercial probiotics is Lactobacillus, a vegetative cell. In contrast, Bacillus spp are bacterial spores, highly resistant to harsh conditions, which makes them preferable, in some cases, to Lactobacillus because of shelf life and storage conditions. There is published information regarding mycotoxin detoxification by bacteria. Mycotoxins are …

Calorimetry And Body Composition Research In Broilers And Broiler Breeders, Justina Victoria Caldas Cueva

Graduate Theses and Dissertations

Indirect calorimetry to study heat production (HP) and dual energy X-ray absorptiometry (DEXA) for body composition (BC) are powerful techniques to study the dynamics of energy and protein utilization in poultry. The first two chapters present the BC (dry matter, lean, protein, and fat, bone mineral, calcium and phosphorus) of modern broilers from 1 – 60 d of age analyzed by chemical analysis and DEXA. DEXA has been validated for precision, standardized for position, and equations and validations developed for chickens under two different feeding levels. These equations are unique to the machine and software in use. Research in broilers …

Responses Of Two Strains Of Broilers To Diets Varying In Essential Amino Acid Density And Energy Levels, Tyler James Clark

Graduate Theses and Dissertations

The responses of two different commercial strains of broilers to diets varying in overall amino acid levels and metabolizable energy levels were observed. Amino acid levels used were 80%, 90%, 100%, 110%, 120%, and 130% of Ross recommended minimum digestable levels of essential amino acids. Energy levels used were either below or above Ross recommended metabolizable energy levels. Diets were fed for 56 days. The two strains were a fast growing broiler strain and a slower growing broiler strain. A selection of birds from each pen was processed at 35, 43, and 56 days of age. Average body weights, cumulative …

Effect Of Feeding Regimen And Age On Lipid Metabolism In Broiler Breeder Hens And Progeny, Nirun Boonsinchai

Graduate Theses and Dissertations

Age of hens and feed allocation can affect egg yolk lipid compositions which in turn directly relate to chick quality. A series of experiments were conducted to determine the effects of age and feeding programs on lipid metabolism in breeder hens and progeny. In the first trial, the rate of yolk absorption and fatty acid profiles in the yolk were compared among 28, 35, and 49wk old hens. The results revealed that the rate of yolk absorption was higher, but the absolute amount of fatty acids absorbed was lower in young hens than in the old hens. The second trial …

Meat Quality Of Broiler Breast Fillets With White Striping And Woody Breast Muscle Myopathies, Vishwesh Vijay Tijare

Graduate Theses and Dissertations

The global poultry industry has been faced with emerging broiler breast meat quality issues known as white striping and woody breast. Two experiments were conducted to evaluate effects of white striping and woody breast hardness on meat quality traits in broiler breast fillets. Birds were processed at 8 wk (Exp.1) and at 6 and 9 wk of age (Exp.2), whereas deboning was carried out at 4 and 2 h postmortem in Exp.1 and 2, respectively. Fillets were categorized as: normal for both white striping and woody breast (NORM); mild for white striping and woody breast (MILD); severe for white striping …

Novel Biomarkers For Calcium And Phosphorus Metabolism In Breeder Hens And Broilers, Andrew Dick Magnuson

Graduate Theses and Dissertations

Broiler breeder hens are subject to the dual expectation to not only maintain a high production of eggs for an extended time period, but to produce eggs which can support the life of chicks which will be used for either meat production or as parent stock. Egg fertility and hatchability are heavily influenced by the thickness of the egg shell, the mineral calcium carbonate shell of the egg necessary for protecting the embryo growing inside. Many factors affect egg shell quality including age of the hen, diet, environmental conditions, genetic strain, stress, disease, and nutrition. Laying hens will mobilize calcium …

Water Consumption Behavior In Broilers, David Harold Mccreery

Graduate Theses and Dissertations

A series of trials were conducted to analyze broiler water consumption behaviors under commercial conditions. The first trial was to quantify the number of broilers drinking at times of peak water demand. Birds were evaluated at time intervals of 5, 10, 15, 30, 45, and 60 minutes from the start of the light period to establish the percentage birds having consumed water by that point in time. Significant differences were found by bird age in the 5, 10, and 15 minute intervals, however there were no significant differences in the percentage of birds having consumed water in the 30, 45, …

The Ability Of Select Probiotics To Reduce Enteric Campylobacter Colonization In Broiler Chickens, Sandip Shrestha

Graduate Theses and Dissertations

Campylobacter is the leading cause of foodborne illness worldwide and is often associated with consumption and/or mishandling of contaminated poultry products. Probiotic use in poultry has been an effective strategy in reducing other enteric foodborne pathogens but not consistently for Campylobacter. As Campylobacter resides and utilizes intestinal mucin for growth, isolates selected on the basis of mucin utilization might be a strategy to screen for efficacious probiotic bacterium. In this study, bacterial isolates demonstrating increased growth rates in mucin, in vitro (trials 1 or 2), or isolates demonstrating a reduction of Campylobacter counts when co-incubated with mucin, in vitro (trials …

Poultry Production Messaging: A Content Analysis Of Three National Newspapers From 1994 To 2014, Stuart Estes

Graduate Theses and Dissertations

Consumers are increasingly concerned with the use of antibiotics and hormones in poultry production, and the news media is the primary way consumers gain knowledge about this subject. This study assessed articles about antibiotic and hormone use in poultry production from the New York Times, USA Today, and the Wall Street Journal from 1994 to 2014. This study employed a content analysis methodology to assess selected articles (n = 139) for key messaging about antibiotic and hormone use in poultry production, article tone, article framing, and article journalistic quality. Data gathered from key messages were assessed for emergent themes that …

Divergent Selection For Four-Day Relative Breast Yield And The Effect Of Thermal Manipulations On Growth Characteristics On Lines Selected For Different Processing Dates., James Grant Mason

Graduate Theses and Dissertations

Genetic selections currently utilized in the poultry industry have been highly successful in promoting broiler growth rate and yield. However, these selections may have come at the expense of broiler physiology, as evidenced by an increase in physiological disorders. To address this experimentation was undergone to develop a novel method of selection to promote growth with minimal physiological impact and to assess how a new embryonic technique affects growth in broiler lines exhibiting different growth rates.

In the first experiment, a random bred control (RAN) broiler line was divergently selected for four-day relative breast yield (BY4) resulting in the high …

Efficacy Of Beta-Resorcylic Acid To Reduce Campylobacter Jejuni In Pre-Harvest And Post-Harvest Poultry, Basanta Raj Wagle

Graduate Theses and Dissertations

Campylobacteriosis is one of the leading foodborne illnesses in United States, and is associated with the consumption of poultry and poultry products. Reducing Campylobacter in these species will reduce the burden of this disease. Unfortunately, most strategies employed to reduce Campylobacter in poultry have either not been successful or produced inconsistent results. One potential control strategy is the use of β-resorcylic acid (BR), a phytophenolic compound classified by the US FDA as "Everything Added to Food in the United States" (EAF 3045) and is therefore deemed safe for consumption. This compounds has antibacterial activity against Salmonella, however, its efficacy to …