title: Comparison of the effect of a CIDR-Select Synch versus a long-term CIDR based AI protocol on reproductive performance in multiparous dairy cows in Swiss dairy farms.
abstract: BACKGROUND
  Synchronization programs have become standard in the dairy industry in many countries. In Switzerland, these programs are not routinely used for groups of cows, but predominantly as a therapy for individual problem cows. The objective of this study was to compare the effect of a CIDR-Select Synch and a 12-d CIDR protocol on the pregnancy rate in healthy, multiparous dairy cows in Swiss dairy farms.
  
  
  METHODS
  Cows (N = 508) were randomly assigned to CIDR-Select Synch (N = 262) or 12-d CIDR (N = 246) protocols. Cows in the CIDR-Select Synch group received a CIDR and 2.5 ml of buserelin i.m. on d 0. On d 7, the CIDR insert was removed and 5 ml of dinoprost was administered i.m.. Cows in the 12-d CIDR group received the CIDR on d 0 and it was removed on d 12 (the routine CIDR protocol in Swiss dairies). On d 0 a milk sample for progesterone analysis was taken. Cows were inseminated upon observed estrus. Pregnancy was determined at or more than 35 days after artificial insemination. As a first step, the two groups were compared as to indication for treatment, breed, stud book, stall, pasture, and farmer's business using chi square tests or Fisher's exact test. Furthermore, groups were compared as to age, DIM, number of AI's, number of cows per farm, and yearly milk yield per cow using nonparametric ANOVA. A multiple logistic model was used to relate the success of the protocols to all of the available factors; in particular treatment (CIDR-Select Synch/12-d CIDR), milk progesterone value, age, DIM, previous treatment of the uterus, previous gynecological treatment, and number of preceding inseminations.
  
  
  RESULTS
  The pregnancy rate was higher in cows following the CIDR-Select Synch compared to the 12-d CIDR protocol (50.4% vs. 22.4%; P < 0.0001).
  
  
  CONCLUSIONS
  The CIDR-Select Synch protocol may be highly recommended for multiparous dairy cows. The reduced time span of the progesterone insert decreased the number of days open, improved the pregnancy rate compared to the 12-d CIDR protocol and the cows did not to have to be handled more often.
authors: Food Animal Practice Rudolph, CH-6284 Sulz, Switzerland.
authors: Jürn
authors: J
authors: Rudolph
authors: Rupert M
authors: RM
authors: Bruckmaier
authors: Ramanathan
authors: R
authors: Kasimanickam
authors: Adrian
authors: A
authors: Steiner
authors: Marc
authors: M
authors: Kirchhofer
authors: Jürg
authors: J
authors: Hüsler
authors: Gaby
authors: G
authors: Hirsbrunner
mesh_terms: D000020:Abortifacient Agents, Nonsteroidal / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D015237:Dinoprost / Q000494:pharmacology; D004973:Estrus Synchronization / Q000379:methods*; D005260:Female; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary*; D016015:Logistic Models; D008297:Male; D008892:Milk / Q000737:chemistry*; D010298:Parity; D011247:Pregnancy; D018873:Pregnancy Rate; D011374:Progesterone / Q000032:analysis; D011897:Random Allocation; D012098:Reproduction / Q000187:drug effects / Q000502:physiology*; D013557:Switzerland; D013997:Time Factors
chemical_list: D000020:Abortifacient Agents, Nonsteroidal; D011374:Progesterone; D015237:Dinoprost