Table 2.

Comparison of the outputs of the model of BVDV spread in a beef cow-calf herd cumulated over the acute (years 1 to 3 after initial introduction) versus the endemic phase (years 6 to 15)

Output definition	Acute phase	Endemic phase
Average probability of virus presence1	0.75-0.76-0.76	0.14-0.17-0.25
Average frequency of herd reinfection1 (yr-1)	0-0.02-0.08	0-0.14-0.38
Median prevT (when the virus is present) (%)	1.3-1.5	0.5-1.0
Median prevP (when the virus is present) (%)	1.4-3.5	0-1.2
Median prevRP (when the virus is present) (%)	2.1-5.5	0-1.3
Median losses/100 bred females	23-37	12-53
Median purchases/100 bred females	13-26	34-125
Median sales of grassers & heifers/100 bred females	-7--2	-1-29
Median sales of fattened females/100 bred females	10-23	23-108
Median weaned calves/100 bred females	-5--2	2-39

Ranges came from variations in herd size, type of initial virus introduction, and external risk of reintroduction.

¹For three levels of K _ext = {0, 0.0025, 0.01} (per day).