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Full-Text Articles in Animal Sciences
A Survey Of Anthelmintic Resistance In Angus Bulls Participating In Centralized Performance Tests In Appalachia, Roger Tyler Rohrbaugh
A Survey Of Anthelmintic Resistance In Angus Bulls Participating In Centralized Performance Tests In Appalachia, Roger Tyler Rohrbaugh
Graduate Theses, Dissertations, and Problem Reports
Resistance to anthelmintics, more commonly referred to as “de-wormers,” has been on the rise in parasites that affect cattle. Parasite infection can have severe impacts on calf productivity resulting in reduced profitability. Therefore, we sought to better understand anthelmintic resistance in Appalachia by surveying Angus bulls entering performance tests in VA and WV. During a four-year period, over 1050 Angus bulls were tested at bull development facilities in Wardensville, WV, Culpeper, VA and Wytheville, VA. Fecal samples were collected at arrival and 14-21 days later for determination of fecal egg count (FEC) reduction. Upon arrival, all bulls received either fenbendazole …
The Effects Of Genetic Differences In An Innate Immune Receptor On Immune Responses To Haemonchus Contortus In Sheep, Denzel Deshawn Middleton
The Effects Of Genetic Differences In An Innate Immune Receptor On Immune Responses To Haemonchus Contortus In Sheep, Denzel Deshawn Middleton
Graduate Theses, Dissertations, and Problem Reports
Little is known about differences observed in early immunological signaling events that result in cellular infiltration and Th2 cytokine production that mediate parasite expulsion. Parasite resistant St. Croix (STC) sheep have been used as model for full host protective immunity as they present the ability to respond to larval stages of H. contortus. RNA sequencing analysis of peripheral blood mononuclear cells (PBMC) stimulated with H. contortus larval antigen (HcLA) revealed significant upregulation in NLRP3 and its pathway component TLR4. Predicted protein structural software identified distinct differences in NLRP3 protein structure in STC and parasite susceptible Suffolk (SUF) sheep. NLRP3 …
Haemonchus Contortus Antigen Identification And Use Of Tropomyosin In Ovine Vaccine Development, Brynnan P. Russ
Haemonchus Contortus Antigen Identification And Use Of Tropomyosin In Ovine Vaccine Development, Brynnan P. Russ
Graduate Theses, Dissertations, and Problem Reports
Globally, the small ruminant industry loses hundreds of millions of dollars due to parasitism by the gastrointestinal nematode Haemonchus contortus. This parasite feeds on blood in the host’s abomasum leading to disease including anemia, hypoproteinemia, lethargy, and death. There have been exhaustive efforts to manage this parasite including different management applications, anthelmintic treatment, and now integration of resistance genetics into a flock. Like antibiotics, overuse of anthelmintics has led to resistance of H. contortus to these drugs. Therefore, other methods of control are the main focuses of many research initiatives. St. Croix are a resistant breed of sheep that mount …
Characterization Of Ovine Monocytes In Response To Haemonchus Contortus Larvae In Vitro And A Novel Role Of Interleukin-13 Inducing Larval Paralysis, Elizabeth Shepherd
Characterization Of Ovine Monocytes In Response To Haemonchus Contortus Larvae In Vitro And A Novel Role Of Interleukin-13 Inducing Larval Paralysis, Elizabeth Shepherd
Graduate Theses, Dissertations, and Problem Reports
Haemonchus contortus is a hematophagous, gastrointestinal parasite affecting small ruminants. Parasitism by H. contortus is the greatest concern of sheep producers in the United States and accounts for billions of dollars in economic loss worldwide. However, different breeds of sheep display differences n natural resistance to H. contortus. St. Croix hair sheep have a remarkable ability to clear H. contortus without the aid of anthelmintics and develop a robust T helper type 2 (Th2) immune response, preventing establishment of infective stage 3 larvae (L3), when compared to susceptible Suffolk sheep. However, the mechanism of development of immune response and …