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Full-Text Articles in Life Sciences

Assessing The Legacy Of Erosion And Flood Control Management Efforts On The Fish Assemblages And Physical Conditions Of Yazoo Basin Bluff Hill Streams, Nicky M. Faucheux Dec 2022

Assessing The Legacy Of Erosion And Flood Control Management Efforts On The Fish Assemblages And Physical Conditions Of Yazoo Basin Bluff Hill Streams, Nicky M. Faucheux

Theses and Dissertations

The hills of Yazoo Basin have a long history of land use modification and subsequent erosion and flood control issues. In response, federal actions were taken to address these issues beginning after the Mississippi River flood of 1927. Four major flood control reservoirs were built in 1932-1957, and instream low-drop grade control structures (GCS) were installed beginning in the 1980s. The objective of my dissertation was to ascertain the long-term effects of these efforts on stream fish assemblages and channel morphology. To assess whether the reservoirs affected upstream fish assemblages as barriers to recolonization by fluvial fishes or as source …


Animal Husbandry In The 21st Century: Application Of Ecological Theory And Precision Technology To Inform Understanding Of Modern Grazing Systems, Ira Lloyd Parsons Dec 2022

Animal Husbandry In The 21st Century: Application Of Ecological Theory And Precision Technology To Inform Understanding Of Modern Grazing Systems, Ira Lloyd Parsons

Theses and Dissertations

Ruminant animals comprise the greatest proportion of herbivores around the world, provide essential ecosystem services and human consumable protein by consuming grass and human inedible dietary fiber. Herbivory pressure alters plant communities and species diversity, effectively making grazing animals ecosystem engineers in dynamic ecosystems. Development of advanced computer processing power coupled with biometric and ecosystem sensors may be employed in the internet of things framework to create an integrated information system designed to inform understanding of grazing system function and animal energy balance. Towards this end, I utilized Bos indicus / Bos taurus crossbred steers (n = 20) across two …


Effects Of Microcystin-Lr On Channel Catfish (Ictalurus Punctatus) Susceptibility To Microbial Pathogens (Aeromonas Hydrophila And Edwardsiella Piscicida), Alison Marchant Dec 2022

Effects Of Microcystin-Lr On Channel Catfish (Ictalurus Punctatus) Susceptibility To Microbial Pathogens (Aeromonas Hydrophila And Edwardsiella Piscicida), Alison Marchant

Theses and Dissertations

Microcystin-LR is a hepatotoxin produced by cyanobacteria. Aeromonas hydrophila and Edwardsiella piscicida infections are leading causes of losses in market-sized channel catfish (Ictalurus punctatus). These older fish should have natural immunity in place and a predisposing factor is likely a prerequisite for these disease outbreaks. While microcystin-LR rarely causes mortality in warm-water aquaculture, we believe it may be a predisposing factor that leads to bacterial disease outbreaks during the summer months due to its ability to damage the liver. Our study investigated microcystin-LR’s effects on channel catfish susceptibility to these pathogens. We found that a sublethal dose of microcystin-LR induced …


The Use Of 87sr/86sr Isotopic Ratios To Assess Natal Areas And Movement Of Juvenile Gulf Sturgeon Acipenser Oxyrinchus Desotoi In The Pascagoula And Pearl River Systems, Joshua Neary Dec 2022

The Use Of 87sr/86sr Isotopic Ratios To Assess Natal Areas And Movement Of Juvenile Gulf Sturgeon Acipenser Oxyrinchus Desotoi In The Pascagoula And Pearl River Systems, Joshua Neary

Theses and Dissertations

The effects of water and dietary influence, and time duration for discernment, of pectoral fin spine 87Sr/86Sr were evaluated in Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus. Fish were subjected to 87Sr-enriched water (0.1 mg/L) or diet (0.25 migrogram/g or 0.5 microgram/g) for 1, 2, 3, 6, or 12 weeks. Fish were also held at 15 or 25°C to determine if temperature influenced 87Sr/86Sr. Results found fin spine 87Sr/86Sr changed in water after 1 week and diet after 12 weeks suggesting water is the primary influence. In wild Gulf Sturgeon A. o. …


Vegetation And Nutritional Changes Over 20 Years Of White-Tailed Deer Exclusion, Gabrielle Nicole Ripa Dec 2022

Vegetation And Nutritional Changes Over 20 Years Of White-Tailed Deer Exclusion, Gabrielle Nicole Ripa

Theses and Dissertations

Knowledge of the impacts of white-tailed deer (Odocoileus virginianus; hereafter deer) as dominant herbivores throughout the Southeastern United States of America is lacking. To address this, three paired experimental units of exclosures and controls were constructed in 2000 on three Wildlife Management Areas across Mississippi within the ecoregions of the Upper Coastal Plain, Lower Coastal Plain, and the Mississippi Alluvial Valley. Vegetation was sampled in the summers of 2000, 2005, and 2021 including vegetation structure, canopy coverage, basal area, and species composition. Additionally, in 2005 and 2021, biomass was sampled to determine potential impacts on nutritional carrying capacity. Among the …


Evaluation Of Novel Litter Amendments For Use In The Commercial Broiler Industry, Jorge A. Urrutia Dec 2022

Evaluation Of Novel Litter Amendments For Use In The Commercial Broiler Industry, Jorge A. Urrutia

Theses and Dissertations

Poultry litter amendments (LA) are commonly used to maintain good litter quality; the most common ones; are acidifiers. However, concern over the lifespan of LA acidifiers (d) and corrosive nature revealed a need for alternative LA. Products of interest include biochar (BC), superabsorbent polymers (SAPs), and alum mud (AM). Experiment 1 was a screening study (n=17 treatments, no birds) conducted to determine the optimal application rate/method of BC, SAPs, and AM vs.commercial LA and a control. Most SAPs treatments measured metrics may be similar (i.e., bacteria, water activity) or better (pH) vs. commercial LA (PLT). High inclusions of novel LA …


Incorporating Follicle Stimulating Hormone To Stimulate Multiple Corpora Lutea For Embryo Transfer In Beef Cattle, Bryan Carter Aug 2022

Incorporating Follicle Stimulating Hormone To Stimulate Multiple Corpora Lutea For Embryo Transfer In Beef Cattle, Bryan Carter

Theses and Dissertations

Assisted reproductive technologies, such as estrus synchronization and embryo transfer, can aid producers in improving genetics by increasing the number of progeny produced from elite females. The success of embryo transfer is dependent on a viable, competent embryo and a recipient with a receptive uterine environment. Follicular development and luteinization are pertinent for the recipient to establish a functional corpus luteum (CL) that can produce adequate concentrations of progesterone (P4) and provide a uterine environment conducive for the establishment of pregnancy. The objective of this study was to determine if exogenous follicle stimulating hormone (FSH), would increase the number of …


The Effects Of Moderate And High Temperatures On Growth, Metabolism, And Blood-Oxygen Affinity In Ictalurus Spp., Brandon Gerhart Aug 2022

The Effects Of Moderate And High Temperatures On Growth, Metabolism, And Blood-Oxygen Affinity In Ictalurus Spp., Brandon Gerhart

Theses and Dissertations

Despite the growing use of hybrid catfish (Ictalurus furcatus × I. punctatus) in aquaculture, few studies have investigated the comparative effects of temperature on physiological performance with other cultured catfish. Therefore, growth, metabolism, and blood-oxygen affinity of blue (I. furcatus), channel (I. punctatus), and hybrid catfish were compared at moderate (23°C) and high (33°C) water temperatures. Channel catfish had the greatest growth and were in better condition compared to blue and hybrid catfish. Hybrid catfish standard metabolic rates did not differ from blue or channel catfish, while hybrid catfish had higher maximum metabolic rates, …


Inosine 5’- Monophosphate Derived Umami Flavor Intensity Of Beef Determination By Electrochemistry And Chromatography, Kezia Virellia To Aug 2022

Inosine 5’- Monophosphate Derived Umami Flavor Intensity Of Beef Determination By Electrochemistry And Chromatography, Kezia Virellia To

Theses and Dissertations

The umami sensation contributes to beef flavor and acceptability. Inosine 5’- monophosphate (IMP) was the most abundant nucleotide in meat known to impart umami taste which thus far had been overlooked in meat flavor studies. The objectives of this study were to determine the umami taste threshold of inosine 5'-monophosphate (IMP), the effects of spiking IMP on the sensory descriptive attributes of various USDA graded beef strip steaks, and to differentiate beef by IMP content using electrochemistry. USDA Prime, Choice, and Select steaks were spiked with 0.3 and 0.6 mM IMP and analyzed chemically and organoleptically. Liquid chromatography-mass spectrometry and …


Effects Of Temperature On Growth, Metabolic Rate, And Lower Dissolved Oxygen Tolerance Of Speckled Peacock Bass Cichla Temensis, Manuel E. Coffill-Rivera Aug 2022

Effects Of Temperature On Growth, Metabolic Rate, And Lower Dissolved Oxygen Tolerance Of Speckled Peacock Bass Cichla Temensis, Manuel E. Coffill-Rivera

Theses and Dissertations

I examined the effects of temperature (25, 30, and 35°C) on growth, standard metabolic rate (SMR), and lower dissolved oxygen tolerance (LDOT) of juvenile Speckled Peacock Bass Cichla temensis. Fish were acclimated to 150-L aquaria for 7 weeks before the growth, SMR, and LDOT experiments. The growth study lasted 58 days and fish acclimated to 25 and 30°C displayed similar growth rates, while fish acclimated to 35°C had very poor growth rates. The SMR and LDOT experiments were performed using intermittent respirometers. Fish acclimated to 25°C had the lowest SMR, followed by 30°C, and finally 35°C. The highest LDOT …


Effectiveness Of Food-Grade Coating Treated Nets After Various Drying Methods At Controlling Mite Growth On Dry-Cured Hams, Sadie White Aug 2022

Effectiveness Of Food-Grade Coating Treated Nets After Various Drying Methods At Controlling Mite Growth On Dry-Cured Hams, Sadie White

Theses and Dissertations

Tyrophagus putrescentiae, known as the ham mite, is the most difficult pest to control in the dry-cured ham industry. Food-grade propylene glycol coated nets have been studied as an alternative to conventional mite infestation treatments but were heavy and costly to ship. This study aimed to increase the ease of use of the coated nets via drying. Three drying treatments: oven dried for 7 min (OD7m), oven dried for 20 min (OD20m), and counter dried for 24 h (CD24h), were tested to determine the efficacy at controlling mites as well as the mechanical properties of the nets and sensory characteristics …


Effects Of The In Ovo Administration Of The Poulvac E. Coli Vaccine In Layer Hatching Eggs On Hatchability, Hatchling Characteristics, And Early Posthatch Chick Performance, Lauren L. Lindsey Aug 2022

Effects Of The In Ovo Administration Of The Poulvac E. Coli Vaccine In Layer Hatching Eggs On Hatchability, Hatchling Characteristics, And Early Posthatch Chick Performance, Lauren L. Lindsey

Theses and Dissertations

Avian Pathogenic E. coli can lead to infections in laying hens and wide-spread economic problems in the table egg industry. A vaccine widely used to combat APEC is the Poulvac E. coli vaccine, which is normally applied via spray vaccination. Application of this vaccine via in ovo injection has not been examined. The purpose of this series of studies was to determine the effects of injecting 50 μL of different dosages of the PECV into Hy-Line W-36 layer hatching eggs on the hatchability and characteristics of the hatchlings, and on the livability and characteristics of the chicks through 21 d …


Maternal Nutrient Restriction And Melatonin Supplementation Alter Neurotransmitter Pathways In Bovine Fetal And Placental Tissues, Allison R. Harman Aug 2022

Maternal Nutrient Restriction And Melatonin Supplementation Alter Neurotransmitter Pathways In Bovine Fetal And Placental Tissues, Allison R. Harman

Theses and Dissertations

Nutrient restriction is a relatively common production insult to pregnancy in cattle. Recently, melatonin supplementation has been investigated as a possible therapeutic to rescue the negative effects of nutrient restriction. Neurotransmitters have been implicated as having negative programming effects in mouse and human pregnancies, manifested as metabolic and neurologic disorders. The role of neurotransmitters in fetal development has only begun to be understood in mice and humans. Neurotransmitters have not been analyzed in cattle, much less within the context of a compromised pregnancy. Brangus heifers were allotted to one of four treatments (ADQ-CON, RES-CON, ADQ-MEL, RES-MEL) in either Fall 2019 …


Assessing The Microbiological Profile Of Raw Goat Milk And Understanding Producer Practices And Perceptions, Jacinda Skye Leopard May 2022

Assessing The Microbiological Profile Of Raw Goat Milk And Understanding Producer Practices And Perceptions, Jacinda Skye Leopard

Theses and Dissertations

Raw milk sales are legal in 30 states, including Mississippi, where regulations are largely management-based and not food-safety related. The research objectives were to analyze the microbial profile of raw goat milk from Mississippi farms and assess food safety practices and perceptions of dairy goat farmers. Deficiencies and opportunities for improvement in raw goat milk safety were identified. Staphylococcus spp. was present in most (70%) milk samples but aligned with drying-off. E. coli, Enterobacteriaceae, and coliforms were observed in 4, 10, and 12 samples, respectively; no Salmonella spp. or Listeria monocytogenes were detected. The survey highlighted farmers' need for …


The Effect Of Sprinkler Cooling On Water Conservation, House Environment, And Broiler Performance, Jonathan W. Moon May 2022

The Effect Of Sprinkler Cooling On Water Conservation, House Environment, And Broiler Performance, Jonathan W. Moon

Theses and Dissertations

Maintaining performance and mitigating heat stress of the modern broiler is a challenging task during hot weather conditions. Increased demand of high quality reasonably priced animal protein and predictions of future limited water availability make sustainability and water conservation a worthwhile goal for the poultry industry. The most used form for cooling broilers after wind speed is evaporative cool cell (CC) systems. Though highly effective at cooling the incoming air, they substantially increase the relative humidity inside the house, which hinders the bird’s ability to cool itself through evaporative respiration. Cool cells also utilize mass amounts of water. The objective …


Nesting Ecology Of Wood Ducks And Other Cavity-Nesting Ducks In Mississippi, Justin Taylor Gibson May 2022

Nesting Ecology Of Wood Ducks And Other Cavity-Nesting Ducks In Mississippi, Justin Taylor Gibson

Theses and Dissertations

Man-made nest boxes are surrogate nest sites widely used by waterfowl managers in North America to propagate free-ranging Wood Ducks (Aix sponsa) and other cavity-nesting waterfowl. I monitored 129 and 174 nest boxes in 2020 and 2021, respectively, at Noxubee National Wildlife Refuge and York Woods, Mississippi. I evaluated site-specific biotic and abiotic factors that were potentially influential on nest survival of Wood Ducks and general nesting ecology and apparent nest success of Black-bellied Whistling Ducks (Dendrocygna autumnalis) and Hooded Mergansers (Lophodytes cucullatus). Daily survival rate of Wood Ducks was negatively influenced by increasing encroaching vegetation at Noxubee NWR and …


Economic Aspects Of U.S. Catfish Farming: Technological Progress, Cost Of Regulations, And Economic Contribution, Shraddha Gurupad Hegde May 2022

Economic Aspects Of U.S. Catfish Farming: Technological Progress, Cost Of Regulations, And Economic Contribution, Shraddha Gurupad Hegde

Theses and Dissertations

This research provides a comprehensive picture of the economic status of the U.S. catfish industry through investigating several critical economic aspects such as technological progress, functional production relationships in intensive systems, regulatory costs, and economic contribution of the industry. The use of primary data is a unique aspect of this work reflecting the economic realities of catfish farms. Primary data collected through extensive in-person farm surveys covered over two-thirds of the catfish production areas in the U.S. The results of the study provided evidence of intensification in the U.S. catfish industry through increased adoption of two relatively new alternative production …


Assessing Priority Bird Response To Open Pine Management In Eastern Mississippi, Holly Marie Todaro May 2022

Assessing Priority Bird Response To Open Pine Management In Eastern Mississippi, Holly Marie Todaro

Theses and Dissertations

Fire suppression, combined with lack of forest thinning and short-rotation, monodominant management, has drastically altered the landscape in the southeastern U.S., leading to the loss of open pine ecosystems and associated avian species. Management of open pine ecosystems is a common practice; yet, there remains uncertainty regarding how vegetation structure impacts priority species. Using empirical data, I assessed changes in species abundance and associated vegetation characteristics before and after management. I also sought to identify vegetation characteristics that influence home range establishment and microhabitat selection of Bachman’s Sparrows. Priority species were negatively associated with hardwood midstory and abundance per site …