Background to this monthly summary

This report is produced monthly by EPIC in collaboration with the Animal Health and Welfare Division (AHWD) of the Scottish Government. It has been published at the request of the BVD (Bovine Viral Diarrhoea) Advisory Group and aims to provide information on the progress of the eradication scheme. It describes trends in the data for monitoring progress. In some cases it provides absolute numbers and in others it provides a snapshot of the situation at a regular date each month.

The data is collated from two sources:

The source of the data is signposted to support interpretation, but it should be noted that this report is most useful for discussing trends in the data rather than to extract absolute counts.

All questions about the descriptions in and the production of this report should be directed to . For details about the eradication scheme including information about testing and status definitions go to the Scottish Government website. Details about the scheme with definitions of the statuses are also available in the BVD FAQ section of the EPIC website.

Summary of the Scottish Herd this month

It is possible to scroll left to right in the below table to see previous months of data.

Summary of the BVD test status of Scotland’s breeding herds - for information about the different herd statuses please refer to Scottish Government guidance
Date 05/11/2022 05/10/2022 05/09/2022 05/08/2022 05/07/2022 05/06/2022 05/05/2022
Accredited Negative 1278 1280 1269 1266 1257 1268 1255
Screened Negative 6191 6171 6174 6176 6186 6212 6242
Not Negative 692 729 753 771 801 771 785
Positive 11 14 16 14 13 25 21
Total Eligible Breeding Herds 8172 8194 8212 8227 8257 8276 8303

There were a total of 8,172 breeding cattle holdings registered by ScotEID in Scotland in the reporting month November 2022. Of these 91% were classified as ‘Negative’ for BVD. This is a change of 0.5% since last month, The six-month rolling average percentage of Negative farms is 91% (see table above).

The plot above summarises the change in the proportion of the national breeding herd statuses through time. Not Negative herds are those herds that either have a BVD antigen positive identified in their herd and are still working to hunt for other PIs and establish a negative status, or those farms that have not completed adequate testing to establish a negative status. Positive herds are those that have confirmed antigen positive animals that are apparent PIs where the animal has yet to be removed from the herd. Negative herds are those that through testing of their herd have shown that it is very unlikely that there is a PI within the herd (through either negative results from check tests or from antigen testing the whole herd or all calves over a period of time). The plot below gives the cumulative total of BVD antigen positive animals identified since the start of data collection in 2012.

The above figure gives the percentage of herds that are ‘Not Negative’ by herd type. The farm business type here is determined using the Scottish Agricultural census data and it was not possible to determine the type of farm for 1537 holdings.

The figure below shows the changing numbers of Negative compared to Not Negative herds through time and the figure below allows comparisons between the percentage of Not Negative herds by county.

Laboratory testing summary

The testing data held by EPIC may be more up to date than the herd status data because of the way this data is delivered and processed by EPIC. Therefore, the testing information may be more recent than that for the herd status information already described. The following information comes from the ScotEID BVD testing database.

A total of 1.3528^{4} were tested in the most recently reported month (05/11/2022). There were 2948 blood samples and 1.0573^{4} tissue samples submitted.

The below figures provide summaries of the numbers of individual animals and different samples taken and test types run by month. When combined with the herd status data it is possible to see the peaks in testing matching the seasonal pattern of calf births in the Spring and, to a lesser extent, in the Autumn.