Association between measures of milk quality and risk of violative antimicrobial residues in grade-A raw milk.
OBJECTIVE
To determine whether bulk-tank standard plate counts or plate loop counts and bulk-tank somatic cell counts (SCC) were associated with detection of violative antimicrobial residues in milk from dairy cattle.


METHODS
Longitudinal study.


METHODS
Information for 1994 through 1997 was obtained from a large milk marketing cooperative that operated in multiple states throughout the northeastern and midwestern United States (16,831 herd-years of information from 6,546 farms) and from the Ohio Department of Agriculture Grade-A Milk Certification Program (12,042 herd-years of information from 4,022 farms). Data were analyzed by use of multivariate logistic regression.


RESULTS
For both data sets, odds that a violative antibiotic residue would be detected increased as mean SCC for the herd-year increased. Standard plate counts and plate loop counts were not associated with odds that a violative antibiotic residue would be detected.


CONCLUSIONS
Results of this study suggested that the odds that a violative antibiotic residue would be found in bulk-tank milk increased as mean SCC for the herd-year increased. This suggests that management practices that would be expected to influence SCC may also influence the risk of antibiotic residue violations.
Saville
W J
WJ
Department of Veterinary Preventive Medicine, College of Veterinary Medicine, Ohio State University, Columbus 43210, USA.
Wittum
T E
TE
Smith
K L
KL
D000818:Animals; D002417:Cattle; D002452:Cell Count / Q000662:veterinary; D015169:Colony Count, Microbial / Q000662:veterinary; D004350:Drug Residues / Q000032:analysis*; D016015:Logistic Models; D008137:Longitudinal Studies; D008414:Mastitis, Bovine / Q000175:diagnosis / Q000188:drug therapy; D008892:Milk / Q000737:chemistry / Q000166:cytology / Q000382:microbiology / Q000592:standards*