title: Survey of reproduction management on Canadian dairy farms.
abstract: The objectives of this study were to (1) quantify current reproduction management practices, and (2) assess the association between these practices and herd reproductive performance on dairy farms in Canada. A bilingual survey was developed, validated, and administered from March to May 2014 to collect general and reproduction management and performance measures [annual 21-d pregnancy rate (PR), 21-d insemination rate (IR), and conception risk (CR)]. Associations between management practices and reproductive performance measures were tested using linear regression models. A total of 832 questionnaires were completed online and by mail, representing a response rate of 9%. On average, farms had 77 lactating cows (median=50) and 13 dry cows (median=10), and Holstein was the most common breed (92% of herds). Lactating cow housing was tiestall on 61% of the farms, freestall on 37%, and bedded pack on 2%. The average voluntary waiting period was 58 d in milk (DIM). The main reproduction management practice per farm was defined as the means employed for >50% of inseminations. Farms reported their main reproduction management practice for first and subsequent inseminations, respectively, as visual estrus detection (51 and 44% of herds), timed AI (21 and 23% of herds), automated activity monitoring (AAM; 10 and 10% of herds), other management practice (bulls; 2 and 2% of herds), and a combination of management practices (16 and 21% of herds). On farms using visual estrus detection, cows were observed for signs of estrus on average 3.5 times per day, for an average total of 36 min/d. The most common use of reproductive hormones was to synchronize ovulation using Ovsynch (58% of the farms). Average PR, IR, and CR were 17.6, 44.1, and 40.5%, respectively. In linear regression analyses adjusted for confounders, pregnancy rate was significantly associated with geographic region, housing (tiestall: PR=15.4%, freestall: PR=17.6%), herd size (<50 lactating cows: PR=16.2%, 50-100 cows: PR=16.5%, >100 cows: PR=17.8%), voluntary waiting period (≤60 DIM: PR=17.6%, >60 DIM: PR=15.9%), and frequency of insemination per day (once daily: PR=16.6%, twice or more daily: PR=18.1%). The main reproduction management practice at first and subsequent inseminations was divergently associated with IR and CR, but not with PR (visual heat detection: PR=17.4%, timed AI: PR=18.4%, AAM: PR=17.1%, combined practices: PR=18.2%).
authors.affiliation: Department of Population Medicine, University of Guelph, Guelph, ON N1G 2W1, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Denis-Robichaud
authors.affiliation: Applied Animal Biology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
authors.forename: R L A
authors.initials: RLA
authors.lastname: Cerri
authors.affiliation: Department of Population Medicine, University of Guelph, Guelph, ON N1G 2W1, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Jones-Bitton
authors.affiliation: Department of Population Medicine, University of Guelph, Guelph, ON N1G 2W1, Canada. Electronic address: sleblanc@uoguelph.ca.
authors.forename: S J
authors.initials: SJ
authors.lastname: LeBlanc
mesh_terms: D000818:Animals; D002170:Canada; D002417:Cattle; D003612:Dairying; D000072480:Farms; D005260:Female; D007315:Insemination, Artificial / Q000662:veterinary; D007774:Lactation; D008297:Male; D012098:Reproduction; D011795:Surveys and Questionnaires
keywords: Canada; reproduction management; reproductive performance; survey