Skip to main content

Research Repository

Advanced Search

Associations between small ruminant lentivirus infection and total milk yield and somatic cell count in a dairy sheep flock

Davies, Peers; Jones, Scott; Dunham, Stephen; Tarlinton, Rachael E.

Associations between small ruminant lentivirus infection and total milk yield and somatic cell count in a dairy sheep flock Thumbnail


Authors

Peers Davies

Scott Jones



Abstract

Background
Small ruminant lentiviruses (SRLVs) are lentiviruses of sheep and goats, formerly known as maedi–visna (MV) in sheep and caprine encephalitis and arthritis in goats. In sheep, SRLVs commonly cause progressive pneumonia, wasting and indurative mastitis. SRLVs have a long latent period, and chronic production losses are often not recognised until very late. Few studies quantifying the production losses in ewes have been published, and none have been published under UK flock husbandry conditions.

Methods
Production records of milk yield and somatic cell count (SCC) from a dairy flock of 319 milking East Friesian × Lacaune ewes identified as MV infected via routine serological screening for SRLV antibodies were used in multivariable linear regression modelling to estimate the impact of SRLV status on total milk yield and SCC.

Results
Milk yield was reduced in seropositive ewes by 8.1%–9.2% over an entire lactation. SCC counts were not significantly different in SRLV-infected and unifected animals.

Limitations
Further parameters, such as body condition score or clinical mastitis, that were not available may have clarified the underlying cause of milk yield drop.

Conclusions
The study demonstrates substantial production losses in an SRLV-affected flock and highlights the impact of the virus on a farm's economic viability.

Citation

Davies, P., Jones, S., Dunham, S., & Tarlinton, R. E. (2023). Associations between small ruminant lentivirus infection and total milk yield and somatic cell count in a dairy sheep flock. Veterinary Record, 192(11), Article e2731. https://doi.org/10.1002/vetr.2731

Journal Article Type Article
Acceptance Date Feb 6, 2023
Online Publication Date Feb 21, 2023
Publication Date Jun 3, 2023
Deposit Date Mar 14, 2023
Publicly Available Date Mar 14, 2023
Journal Veterinary Record
Print ISSN 0042-4900
Electronic ISSN 2042-7670
Publisher BMJ Publishing Group
Peer Reviewed Peer Reviewed
Volume 192
Issue 11
Article Number e2731
DOI https://doi.org/10.1002/vetr.2731
Keywords Maedi–Visna, milk, sheep, small ruminant lentivirus
Public URL https://nottingham-repository.worktribe.com/output/17665478
Publisher URL https://bvajournals.onlinelibrary.wiley.com/doi/full/10.1002/vetr.2731

Files





You might also like



Downloadable Citations