Abomasal mucosal immune responses of cattle with limited or continuous exposure to pasture-borne gastrointestinal nematode parasite infection.
It has been well documented that cattle raised on pasture are slow in weight gain when compared to those fed with grain. Inflammation in the digestive system commonly caused by pasture-transmitted gastrointestinal (GI) nematode parasites that could negatively impact feed conversion has never been compared in cattle raised with no pasture exposure (NPE, uninfected), limited pasture exposure (LPE, exposure until weaning), or continuous pasture exposure (CPE, life time exposure). In the present study, the abomasal mucosal immune responses and inflammation of LPE and CPE cattle were investigated. Our results indicate that CPE cattle displayed inflamed abomasa with enlarged draining lymph nodes, the presence of Ostertagia ostertagi larvae and higher levels of Ostertagia-specific antibodies in circulation. The level of B cells was elevated in the abomasal mucosa in the presence (nodular) or absence (non-nodular) of Ostertagia-specific pathology, where B cells were 4-fold higher in the nodular mucosa. Foxp3+CD4T cells were also noticeably elevated in both the abomasal mucosa and blood, but were only slightly higher in non-nodular mucosa than in the nodular mucosa of CPE animals. In contrast, LPE animals presented no enlargement of abomasal draining lymph nodes and exhibited little to no immune cell infiltration in the abomasal mucosa. Further, CPE animals had higher numbers of mucosal mast cells when compared to LPE animals, though mucosal mast cells were high in all animals. Overall, CPE cattle displayed significantly higher levels of inflammation and pathology in their abomasa and may explain in part slowed weight gain relative to LPE animals. The results of this study emphasize the need for GI nematode parasite control in CPE animals and development and application of vaccines which are compatible with the organic cattle production system.
Animal Parasitic Diseases Laboratory, USDA/ARS, Beltsville, MD 20705, United States. Electronic address: Wenbin.tuo@ars.usda.gov.
Wenbin
W
Tuo
Department of Department of Avian and Animal Sciences, University of Maryland, College Park, MD 20742, United States.
Lei
L
Li
Department of Department of Avian and Animal Sciences, University of Maryland, College Park, MD 20742, United States.
Yingjun
Y
Lv
Department of Department of Avian and Animal Sciences, University of Maryland, College Park, MD 20742, United States.
Jose
J
Carrillo
Animal Parasitic Diseases Laboratory, USDA/ARS, Beltsville, MD 20705, United States.
Dedra
D
Brown
Department of Veterinary Microbiology and Pathobiology, Washington State University, Pullman, WA 99164, United States.
William C
WC
Davis
Department of Department of Avian and Animal Sciences, University of Maryland, College Park, MD 20742, United States.
Jiuzhou
J
Song
Animal Parasitic Diseases Laboratory, USDA/ARS, Beltsville, MD 20705, United States.
Dante
D
Zarlenga
Department of Department of Avian and Animal Sciences, University of Maryland, College Park, MD 20742, United States. Electronic address: xiao0028@umd.edu.
Zhengguo
Z
Xiao
D000018:Abomasum / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000469:parasitology* / Q000473:pathology; D005767:Gastrointestinal Diseases / Q000469:parasitology / Q000662:veterinary*; D009092:Mucous Membrane / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D009349:Nematode Infections / Q000378:metabolism / Q000469:parasitology / Q000662:veterinary*
B cells; Cattle; Continuous pasture exposure (CPE); Gastrointestinal nematode parasite; Limited pasture exposure (LPE); No pasture exposure (NPE); Ostertagia ostertagi; T cells