College of Agriculture & Natural Resources
Permanent URI for this communityhttp://hdl.handle.net/1903/1598
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
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Item Development of a Multilocus Sequence Typing Scheme for Avibacterium paragallinarum(2023) Harris, Alyssa Meihua; Ghanem, Mostafa; Veterinary Medical Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Avibacterium paragallinarum (A. paragallinarum), the causative agent of the respiratory disease Infectious Coryza (IC) in chickens, has seen a rising incidence in the United States. Current strain differentiation is inadequate for detailed epidemiological analysis. The objective of this study was to develop a Multilocus sequence typing (MLST) scheme for A. paragallinarum for outbreak investigations and to offer a better tool for strain differentiation. By evaluating whole genome sequences and clinical samples, we designed PCR amplicons for eighteen gene segments, selected six genes for their nucleotide diversity and discrimination potential. The MLST was used to differentiate seventy-five samples. Our MLST showed greater discriminatory power than existing HPG2-based methods, aligning closely with adhoc core genome MLST in 75 tested sample. Our newly developed MLST scheme enables more accurate strain differentiation, allowing for better understanding of A. paragallinarum epidemiology and population structure to help prevention and control efforts worldwide.Item Innovation in Newcastle Disease Virus Vectored Avian Influenza Vaccines(MDPI, 2019-03-26) Kim, Shin-Hee; Samal, Siba K.Highly pathogenic avian influenza (HPAI) and Newcastle disease are economically important avian diseases worldwide. Effective vaccination is critical to control these diseases in poultry. Live attenuated Newcastle disease virus (NDV) vectored vaccines have been developed for bivalent vaccination against HPAI viruses and NDV. These vaccines have been generated by inserting the hemagglutinin (HA) gene of avian influenza virus into NDV genomes. In laboratory settings, several experimental NDV-vectored vaccines have protected specific pathogen-free chickens from mortality, clinical signs, and virus shedding against H5 and H7 HPAI viruses and NDV challenges. NDV-vectored H5 vaccines have been licensed for poultry vaccination in China and Mexico. Recently, an antigenically chimeric NDV vector has been generated to overcome pre-existing immunity to NDV in poultry and to provide early protection of poultry in the field. Prime immunization of one-day-old poults with a chimeric NDV vector followed by boosting with a conventional NDV vector has shown to protect broiler chickens against H5 HPAI viruses and a highly virulent NDV. This novel vaccination approach can provide efficient control of HPAI viruses in the field and facilitate poultry vaccination.Item Enhanced Biogas Production of Cassava Wastewater Using Zeolite and Biochar Additives and Manure Co-Digestion(MDPI, 2020-01-19) Achi, Chibueze G.; Hassanein, Amro; Lansing, StephanieCurrently, there are challenges with proper disposal of cassava processing wastewater, and a need for sustainable energy in the cassava industry. This study investigated the impact of co-digestion of cassava wastewater (CW) with livestock manure (poultry litter (PL) and dairy manure (DM)), and porous adsorbents (biochar (B-Char) and zeolite (ZEO)) on energy production and treatment efficiency. Batch anaerobic digestion experiments were conducted, with 16 treatments of CW combined with manure and/or porous adsorbents using triplicate reactors for 48 days. The results showed that CW combined with ZEO (3 g/g total solids (TS)) produced the highest cumulative CH4 (653 mL CH4/g VS), while CW:PL (1:1) produced the most CH4 on a mass basis (17.9 mL CH4/g substrate). The largest reduction in lag phase was observed in the mixture containing CW (1:1), PL (1:1), and B-Char (3 g/g TS), yielding 400 mL CH4/g volatile solids (VS) after 15 days of digestion, which was 84.8% of the total cumulative CH4 from the 48-day trial. Co-digesting CW with ZEO, B-Char, or PL provided the necessary buffer needed for digestion of CW, which improved the process stability and resulted in a significant reduction in chemical oxygen demand (COD). Co-digestion could provide a sustainable strategy for treating and valorizing CW. Scale-up calculations showed that a CW input of 1000–2000 L/d co-digested with PL (1:1) could produce 9403 m3 CH4/yr using a 50 m3 digester, equivalent to 373,327 MJ/yr or 24.9 tons of firewood/year. This system would have a profit of $5642/yr and a $47,805 net present value.Item The Effects of Tryptophan and Probiotic Treatment on Behavior and Production Parameters of Laying Hens(2021) Bonilla Carrero, Paola Ivette; Dennis, Rachel L; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Dietary supplementation can impact behavior expression through microorganism’s activity in the gut microbiome and influence productivity in animal husbandry. Adding supplements to production animals’ diet can impact behaviors and productivity via gut-brain axis activity. We investigated the effects of either probiotic or antibiotic supplementation in addition to the effects of additional tryptophan (Trp) on overall behavior and production parameters. White Leghorn chickens (n=12) were supplemented with six dietary treatments in a 2 x 3 factorial design: probiotics (1 x 109 CFU/L) or the antibiotic erythromycin (125 mg/L) in combination with either normal (0.16%) or high (0.48%) Trp in drinking water. Results indicate that probiotics with tryptophan increased locomotion (P = 0.04), social (P = 0.04), and eating behavior (P = 0.02). Antibiotics with tryptophan increased fat pad (P = 0.04) and heart weight (P = 0.04). Supplementation affected behavioral expression of normal, comfort, and pecking behavior, potentially impacted by metabolic competition at the level of the gut microbiome.Item Poultry Growers Will Have to Wait a Little Longer for Crop Insurance Coverage(2016-02) Goeringer, Paul; Leathers, HowardThis article reviews recent reports looking at the ability to implement crop insurance products for poultry growers. For both business interruption insurance and disease insurance, USDA concluded that the current legislation would not allow for the Risk Management Agency to develop products that work for these growers.Item Taking Biosecurity Measures to Limit Your Legal Liability for the Spread of Avian Influenza(2015-09-17) Goeringer, Paul; Moyle, Jon; Newhall, AshleyThe possibility of an avian influenza (AI) outbreak on the Delmarva is a scary possibility. The recent AI outbreak in the Midwest has resulted in the infection of over 48 million birds on 223 farms. Infected birds are euthanized to help contain the disease, resulting in large economic loss to both the grower and integrator. With this in mind, poultry growers and companies often have questions about potential liability if AI breaks out on one farm (Grower A) and then on a neighboring farm (Grower B). Could Grower A be liable to Grower B for damages caused by the disease? Under the traditional view, Grower A would not be liable for the spread of the disease unless it was shown that Grower A was negligent. Growers, poultry companies, and contractors practicing biosecurity measures can demonstrate he/she was not negligent and is working to prevent the spread of AIItem QUANTIFICATION OF IONOPHORE ANTIMICROBIALS ASSOCIATED WITH POULTRY LITTER AND THEIR DYNAMICS IN THE SOILS OF THE MID-ATLANTIC USA(2014) Biswas, Saptashati; McGrath, Joshua M; Sapkota, Amir; Environmental Science and Technology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Anticoccidants, biochemically known as ionophores are added to poultry feed for growth promotion, prophylactic and therapeutic purposes to better sorb nutrients and against coccidiosis caused by parasite Eimeria sp. Ionophores belong to the class of emerging contaminants, as they are not regularly monitored in the environment and not specifically treated in the effluents. Potentially, this can cause ionophores to enter into the environment freely. There is little information regarding the dynamics of ionophores in the environment. This has been related to the lack of reliable, sensitive and robust methods that can measure their trace levels from complex environmental matrices like soil, natural water and animal manure. Studies show ionophore toxicity exhibited in flora and fauna, even reported in humans above the dose of 1 mg kg-1. Hence accumulation of ionophores in the environmental can be detrimental. Our multi-scale investigation of ionophores involved, a) method development for trace analysis of ionophores in poultry manure using liquid chromatography triple quadrupole mass spectrometry (HPLC-–MS/MS), b) batch equilibrium studies of ionophores using soils from mid-Atlantic region of the USA and c) influence of soil physico-chemical parameters on dynamics of ionophores in soil-water systems. Our HPLC-–MS/MS method was successful in quantifying ionophores ranging from (19.19 ±± 6.6) µg kg-1 to (97.86 ±± 19.19) µg kg-1 with concentrations of monensin being the highest. This method was further used to investigate partitioning of monensin in soil-ndash;water systems relevant to the occurrence of ionophores in the natural environment. Sorption and desorption isotherms were developed and influence of soil physico-chemical parameters on the sorption-desorption processes were analyzed. C-–type linear isotherms were generated with partition coefficients ranging from (6.41±± 1.34) to (343.83 ±± 5.68) LKg-1. Soil parameters such as cation exchange capacities, pH, organic matter, sand and silt content were found to correlate with sorption in different conditions. A major focus of this dissertation was to develop novel methodologies and design experiments to execute our research objectives.