Table 1.

A summary of sero-epidemiologic studies that have examined the relationship between bovine viral diarrhea virus and bovine respiratory disease in feedlot cattle

Authors	Population studied	% of cattle seropositive to BVDV on arrival	Was arrival titer associated with decreased BRD risk?	% of cattle seroconverting to BVDV virus	Was seroconversion associated with increased BRD risk?
Martin et al 1986 [40]	322 calves, Small pen research feedlots in Ontario	55.8%	No	24%	Yes
Martin et al 1989 [41]	279 cases of BRD and 290 controls from small pen research feedlots in Ontario	32% in cases 42% in controls	Yes	42% in cases 33% in controls	Yes
Durham et al 1991 [42]	283 bull calves at Saskatchewan bull test station	21%	Yes	13%	No
Allen et al 1992 [43]	59 cases of BRD and 60 controls from small pen research feedlot in Ontario	Not applicable	N/A	51%	No
Martin et al 1999 [44]	700 calves from 32 groups from feedlots in Ontario and Alberta	24%	Yes	50%	Yes
Booker et al 1999 [45]	200 head case control study from 22,000 head commercial lot in Alberta	Not calculated	Yes	Not calculated	Yes
Fulton et al 2000 [46]	120 Tennessee calves shipped to Texas	18.3% BVDV type 1 13.3% BVDV type 2	N/A virtually all calves treated	38.5% BVDV type 1 27.9% BVDV type 2	N/A
O'Connor et al 2001 [47]	852 calves from 3 Ontario feedlots	39%	Yes	45%	Yes
Fulton et al 2002 [48]	Two groups of calves: 205 calves and 120 calves from Tennessee	23.1–34.2% BVDV type 1a 17.4–20.0% BVDV type 2	Not calculated	Sick calves: 32.8–47.5% BVDV 1a Healthy calves: 16–28.4% BVDV 1a	Yes