11546
document
The efficacy of intramammary tilmicosin at drying-off , and other risk factors for the prevention of new intramammary infections during the dry period . The objective of this study was to compare the efficacy of an intramammary infusion , containing tilmicosin phosphate , to an infusion of a negative control intramammary placebo for preventing new intramammary infections ( IMI ) during the dry period . Cows were enrolled from 24 dairy herds from three geographical regions of Canada . Data from 248 cows and 938 bacteriologically negative quarters at drying-off are summarized . Overall , the rate of new IMI during the dry period was 16.7 % of quarters . The new infection rates for quarters that received intramammary tilmicosin compared with the intramammary placebo were 14.4 and 19.4 % , respectively . The majority of new IMI was caused by coagulase-negative staphylococci ( 49 % ) and environmental streptococcal organisms ( 26.8 % ) . The probability for quarters to develop new IMI in the dry period was significantly increased when cows had higher milk production before drying-off ( P = 0.04 ) , when cows had longer dry periods ( P = 0.02 ) , and when dry cows were housed in tie-stall barns ( P = 0.002 ) . Higher parity cows and those that had a linear score somatic cell count ( SCC ) above 4 on the last DHI test were also at increased risk for new IMI ( P < 0.10 ) . Administration of intramammary tilmicosin appears to be an efficacious therapy for prevention of new IMI ; however , there is currently no approved intramammary formulation of this product available . Use of blanket dry cow antibiotic therapy compared to selective dry cow therapy , as well as the importance of identifying risk factors and managing the environment of dry cows are discussed .
11547
Intervention_Pharmacological
intramammary tilmicosin
11548
Intervention_Pharmacological
intramammary infusion , containing tilmicosin phosphate
11549
Intervention_Control
infusion of a negative control intramammary placebo
11550
Intervention_Pharmacological
intramammary tilmicosin
11551
Intervention_Pharmacological
intramammary placebo
11552
Intervention_Pharmacological
intramammary tilmicosin
11553
Outcome_Other
efficacy
11554
Outcome_Physical
intramammary infections ( IMI )
11555
Outcome_Physical
rate of new IMI
11556
Outcome_Physical
new infection rates
11557
Outcome_Physical
new IMI
11558
Outcome_Physical
new IMI
11559
Outcome_Physical
linear score somatic cell count ( SCC )
11560
Outcome_Physical
risk for new IMI
11561
Outcome_Physical
prevention of new IMI ;
11562
Participant_Condition
Cows
11563
Participant_Sample-size
248