Analyse de la fertilité des vaches laitières Holstein «Repeat Breeder»
Two factors underlie the Repeat Breeder (RB) concerns in Quebec: its incidence and economic impact. Currently RB incidence in Quebec is of ± 25% (yearly Report, June 2008, www.dsahr.ca). Monetary losses related to the RB are the result of veterinary expenses and insemination, loss of productivity and the involuntary culling.  In order to have a better knowledge of this syndrome, one must understand the general risk factors involved and then explore the individual condition of these problem cows. The goal of the first part of the project was to assess the impact of the postpartum reproductive problems and the effect of the lactation number as risk factors of the Repeat Breeder cow. A computerized data bank listing 418 383 lactations was analyzed. The analysis established dystocia as being the condition with the most consequences on future fertility. Other risk factors namely the number of lactations influence the reproductive prognosis as well. The second part of the research was to explore the individual condition of the RB using clinical tools. A cohort study was conducted on Holstein cows at the end of the voluntary waiting period on day 7 of the oestrous cycle. The clinical tests studied were vaginoscopy, trans-rectal examination, ultrasonography of the reproductive system, presence of leukocyte esterase, bacteriology and biochemistry of uterine fluid, endometrial cytology and serum progesterone profile. The results of these clinical tests reveal that the bacteriological analysis of uterine fluid is indicative of future reproductive status.
Repeat Breeder Repeat Breeder performances reproductrices reproductive perfomance post-partum problems number of lactations culling examination of reproductive system dairy cows