Research Summary - 2
Cross-sectional study to estimate seroprevalence of bluetongue virus, bovine leukemia virus, and Neospora caninum infection in Mississippi beef cow-calf herds
| Date/Time: |
9/12/2025
17:15
|
| Author: |
W.Isaac Jumper |
| Clinic: |
Mississippi State University College of Veterinary Medicine |
| City, State, ZIP: |
Mississippi State, MS 39759 |
W. Isaac Jumper, DVM, PhD, DACVPM (Epi)
1
;
Brandi Karisch, PhD
2
;
Carla L. Huston, DVM, PhD, DACVPM (Epi)
1
;
David R. Smith, DVM, PhD, DACVPM (Epi)
1
;
1Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, 39762
2Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, 39762
Introduction:
The objectives of this study were to estimate the within and between herd seroprevalence of bluetongue virus (BTV), bovine leukemia virus (BLV), and Neospora caninum in Mississippi beef cow-calf herds, as well as determine factors related to herd seroprevalence and individual animal infection status.
Materials and methods:
Serum was collected from all females ≥ 2 years of age (n=2,126) in 40 herds across 23 counties in Mississippi. Enzyme-linked immunosorbent assay (ELISA) was used to test serum for BTV, BLV, and N. caninum antibodies. Participant herds were surveyed to determine herd demographics, biosecurity procedures, and other herd health practices. Logistic regression mixed models were used to test individual animal and herd level factors for association with BTV, BLV, and N. caninum infection status and herd seroprevalence, respectively. Herd was considered a random variable in all models, and statistical significance was defined a priori at alpha=0.05.
Results:
All herds had antibodies to BTV, with the mean within-herd seroprevalence being 96.5%. Thirty-nine of 40 herds (97.5%) had antibodies to BLV, with the mean within-herd seroprevalence being 55.5%. Thirty-four of 40 herds (85%) had antibodies to N. caninum, with the mean within-herd seroprevalence being 8.1%. Factors associated with individual animal BLV infection included age (≥10 years: OR=2.3, 95%C.I.=1.1-4.5; 7-9 years: OR=1.6, 95%C.I.=0.9-2.7; 4-6 years: OR=1.9, 95%C.I.=1.2-2.9; compared to 2-3 years) and body condition score (BCS 5-6: OR=2.1, 95%C.I.=0.9-5.2; BCS 3-4: OR=3.3, 95%C.I.=1.3-8.5; compared to BCS 7-9).
Significance:
Nearly all cattle tested had antibodies to BTV, while more variation was present in within-herd seroprevalence of BLV and N. caninum.
