Veterinary Medicine International

Research Article

Control of Bovine Leukemia Virus in Three US Dairy Herds by Culling ELISA-Positive Cows

Table 3

Bovine leukemia virus (BLV) antibody testing schedule and results for Herd S.
Test DateTest TypeDescriptionResults1
December 2014Herd (milk)All cows in the milking herd8/343 (2.3%)
February 2015Interim (serum)Cows and heifers due to calve in the next six months22/69
March 2015Interim (milk)Cows dry at the December test0/10
July 2015Interim (milk)  
Bulk tank (milk)		All cows and heifers that calved since the March test0/27  
Negative
October 2015Interim (milk)All cows and heifers that calved since the July test2/43
January 2016Herd (milk)All cows in the milking herd1/342 (0.3%)
April 2016Interim (milk)   
Bulk tank (milk)		All cows and heifers that calved since the January test
1/39  
Negative
July 2016Interim (milk)   
Bulk tank (milk)		All cows and heifers that calved since the April test2/31  
Positive
September 2016Interim (serum)Heifers due to calve in the next six months0/38
October 2016Interim (milk)   
Bulk tank (milk)		All cows and heifers that calved since the July test3/30  
Positive
November 2016Interim (serum)Heifers due to calve in the next six months0/10
December 2016Interim (serum)Heifers due to calve in the next six months1/14
January 2017Interim (serum)Heifers due to calve in the next six months1/14
January 2017Herd (milk)   
Bulk tank (milk)		All cows in the milking herd35/343 (1.5%)  
Positive
February 2017Interim (serum)Heifers due to calve in the next six months1/35
March 2017Interim (serum)Heifers due to calve in the next six months0/12
April 2017Interim (serum)Heifers due to calve in the next six months0/8
BLV-antibody positive (“positive”) over total tested, with point prevalence (%) for herd tests.
Excludes one (1) cow tested in December 2014 that was inadvertently re-tested in February.
All five (5) positive animals had previously tested negative on serum as heifers.