| dc.description.abstract | The objective of this study was to gain insight into selective practices for dry cow therapy (DCT) and clinical mastitis (CM) treatment on Canadian dairy farms, as limited information is available in the literature regarding these practices in Canada. A structured questionnaire was completed by 146 dairy producers from five Canadian regions, as part of the Canadian Dairy Network for Antimicrobial Stewardship and Resistance (CaDNetASR) initiative.
Selecting CM cases to treat with antimicrobials was done by 60% of producers compared to blanket treating all cases. Only 41% of producers selecting cases used somatic cell count (SCC) thresholds as criteria, with 200,000 - 300,000 cells/mL used most frequently (55%). Furthermore, symptom severity was considered ‘important’ or ‘very important’ by the vast majority of producers (94%) when deciding on CM treatment. No associations were detected between use of selective CM therapy and province, housing, milking system or herd size.
Blanket DCT (BDCT) was more commonly practiced (65% of producers) compared to selective DCT (SDCT). Furthermore, no associations were detected between type of DCT and herd size, housing, milking system or province. SCC thresholds were frequently used as DCT selection criteria, with 150,000 - 200,000 cells/mL being the most frequently used as cut-off (63%). Information on past CM cases was used to select for DCT by 75% of producers practicing SDCT.
Internal teat sealant was administered to all cattle at dry-off by 59% of producers, more frequently in farms with parlour milking systems compared to pipeline (P = 0.04). Additionally, producers using teat sealant had a higher mean adult cow herd size (155) than producers not using teat sealant (118; P = 0.03). Written treatment protocols for DCT were available at only 29% of farms, whereas treatment protocols for mastitis were available at 50% of farms. In conclusion, there is potential to increase adoption of SDCT and selective CM treatment, which could reduce on-farm AMU. | |
