Volume 16: Reference Material
3. Statistics
Incidence by herd, type of herd and breed

3.9 By 20 March 1996 a little over a third of the 92,000 or so herds in Great Britain had been affected by BSE (see Figure 3.15 below). The proportion of herds affected in Northern Ireland was smaller - just 4 per cent out of a total of over 28,000.

3.10 Figure 3.16 shows the number of newly affected herds each year in Great Britain. The cumulative total for the UK as a whole to 20 March 1996 was 34,690, the total for Northern Ireland being 1,154 (although DANI figures add up to 1,145: see Figure 3.21). By the end of 1996 the number of newly affected herds in Great Britain had increased from 157 to 665. There were 215 newly affected herds in 1999, and 61 in January-June 2000.

Figure 3.15: Cumulative herd incidence of BSE for Great Britain as at 20 March 1996*

Figure 3.16: Number of newly affected herds in Great Britain by year of clinical onset of the first confirmed case of BSE in each herd, up to March 1996*

3.11 The following maps show cumulative and annual herd incidence for Great Britain by county. The data for Northern Ireland, also by county, are presented in tabular form, because the figures are much smaller and within a much narrower range.

Figure 3.17: Cumulative incidence of dairy and beef herds with at least one confirmed case of BSE by county, Great Britain, to 20 March 1996

Figure 3.18: Cumulative incidence of dairy herds with at least one confirmed case of BSE by county, Great Britain, to 20 March 1996

Figure 3.19: Annual incidence of dairy and beef herds with at least one confirmed case of BSE in each year, by county, Great Britain, 1986-97

Figure 3.19: Continued

Figure 3.19: Continued

Figure 3.20: Annual incidence of dairy herds with at least one confirmed case of BSE in each year, by county, Great Britain, 1986-97

Figure 3.20: Continued

Figure 3.20: Continued

Figure 3.21: Cumulative incidence of all herds in Northern Ireland with at least one confirmed case of BSE, by county, to 20 March 1996

Figure 3.22: Annual incidence of all herds in Northern Ireland with at least one confirmed case of BSE in each year, by county, 1988-97 (no cases in 1986-87)

Figure 3.23: Annual incidence of dairy herds in Northern Ireland with at least one confirmed case of BSE in each year, by county, 1988-97 (no cases in 1986-87)

3.12 Dairy herds were far more affected by BSE than beef herds, because dairy cattle were fed protein concentrates - including MBM, the vector of the BSE agent - to a much greater extent than beef cattle. The extra protein in their diet increased milk yields. As Figure 3.15 above shows, nearly two-thirds (61.2 per cent) of dairy herds in Great Britain had been affected by 20 March 1996, compared with under a fifth (15.7 per cent) of beef herds. Figures 3.24, 3.25a and 3.25b below show numbers of cases and herds by production type for the UK as a whole.

Figure 3.24: Number of confirmed cases of BSE by production type, UK, to 20 March 1996

Figure 3.25a: Number of affected herds for each production type, UK, to 20 March 1996

Figure 3.25b: Number of affected herds for each production type, UK, to 20 March 1996

3.13 Friesian cattle dominated the UK herd during the period covered by the Report. In 1986, the British Friesian breed accounted for 86 per cent of the UK dairy herd. ¹ Although this proportion subsequently fell, the continued dominance of the breed helps to explain the high numbers of Friesian cows among confirmed cases of BSE, as shown in Figures 3.26 and 3.27 below. (A Milk Marketing Board survey for 1988/89 estimated the percentage of Friesians in the total of confirmed cases at 94 per cent.) A separate table has been included for Northern Ireland, because the pattern there was slightly different.

Figure 3.26: Number of confirmed cases of BSE in purebred cows in dairy herds, Great Britain, by year of clinical onset, to 20 March 1996, and percentage of total by breed per year

Figure 3.27: Number of confirmed cases of BSE in purebred cows in dairy herds, Northern Ireland, by year of clinical onset, to 20 March 1996, and percentage of total by breed per year