VetMedOvarian follicular cysts in dairy cows: GnRH-based vs progesterone-based therapy — MAYBE (weak evidence)
In dairy cows with ovarian follicular cysts, does GnRH-based vs progesterone-based therapy give better resolution and pregnancy rates?
Shelf #891 · gate-verified and approved by the developer
MAYBE (weak evidence): In dairy cows with ovarian follicular cysts, neither GnRH-based nor progesterone-based therapy has been shown to give better pregnancy rates — the largest direct comparison found no significant difference, and the one randomised trial favouring a progesterone-based protocol compared it against a weaker GnRH strategy (a single GnRH injection with AI at detected oestrus) rather than against a full GnRH-based timed-AI programme. In Crane 2006 (PMID: 16229884; 401 lactating dairy cows with ovarian cysts, alternatively allocated), return to cyclicity (a corpus luteum on day 21) was 83% with Ovsynch (GnRH-based) vs 79% with a 7-day CIDR protocol (progesterone-based) (P > 0.05), conception rate was 18.3% vs 23.1% and pregnancy rate 14.4% vs 9.5%, with no significant difference in conception or pregnancy rates; the Ovsynch group was more likely to be inseminated (82% vs 44%; odds 5.8 times higher), because CIDR cows were only inseminated if seen in oestrus. In Kim 2006 (PMID: 16288840; 135 cows with follicular cysts, randomly assigned), conception rate was 52.3% with a CIDR-based timed-AI protocol vs 26.9% with a single GnRH injection followed by AI at oestrus (P < 0.05; absolute difference 25.4 percentage points) — but the arms differ in insemination method (timed AI vs oestrus detection) as well as in progesterone, so the advantage cannot be attributed to progesterone alone. In Kawate 2011 (PMID: 21242655; 38 cows with cystic ovarian disease), adding a CIDR to Ovsynch changed neither hormone concentrations nor conception rate significantly. In Abdalla 2020 (PMID: 32622197; 552 cows with follicular cysts, nonrandomised, single herd), CIDR-added regimens were associated with non-significant increases in pregnancy per AI vs Ovsynch (new CIDR: odds ratio 2.1, P = 0.09 at day 30; absolute pregnancy rates are not reported in the abstract). Design class (b): randomisation is established by Kim 2006, a randomised trial answering a GnRH-strategy vs progesterone-inclusive-strategy comparison in cows with follicular cysts; blinding is not established in any carded record, Crane 2006 is class (c) on its own (alternate allocation, not randomisation) and Abdalla 2020 is explicitly nonrandomised. The stamp is MAYBE (weak evidence) because the direct evidence is small, internally inconsistent, and confounded by insemination method in the only positive trial. Tier C is not engaged: no mortality or survival claim is made. Drafted Nov 10, 2026 (VetMed build, topic #891); figures from the abstracts, fetched and verified at drafting.
Crane 2006: in 401 cows with ovarian cysts, Ovsynch vs CIDR did not differ in cyclicity (83% vs 79%), conception (18.3% vs 23.1%) or pregnancy rate (14.4% vs 9.5%)
Controlled field comparison with ALTERNATE (not random) allocation — the record's own wording is 'alternatively allocated' (publication types: Journal Article)
Who: Dairy cattle: 401 lactating dairy cows with ovarian cysts in a commercial herd, alternatively allocated on the day of diagnosis to Ovsynch (GnRH day 0, prostaglandin F2alpha day 7, GnRH day 9, timed insemination 16-20 h later) or a CIDR protocol (CIDR insert day 0 for 7 days, removed day 7 with prostaglandin F2alpha; cows then observed for oestrus and inseminated if in oestrus within 7 days of removal). Outcomes included likelihood of insemination, return to cyclicity (corpus luteum on day 21), conception and pregnancy rates, analysed by logistic regression.
Result: The percentage inseminated was 82% in the Ovsynch group vs 44% in the CIDR group (Ovsynch cows 5.8 times more likely to be inseminated). A corpus luteum on day 21 (return to cyclicity) was present in 83% vs 79% (P > 0.05). Conception rate was 18.3% (Ovsynch) vs 23.1% (CIDR) and pregnancy rate 14.4% vs 9.5%, with no significant differences between conception or pregnancy rates in the two groups. Primiparous cows were 2.6 times more likely to conceive than multiparous cows, and cows with low body condition score were less likely to be inseminated (odds 0.48) and to have a corpus luteum on day 21 (odds 0.49) regardless of treatment. The authors concluded fertility was not different between cows with ovarian cysts treated with either the Ovsynch or the CIDR protocol in this herd.
Watch out: Allocation was alternate, not randomised, so this card alone is design class (c) despite the record carrying a 'Random Allocation' MeSH term — the abstract's own allocation wording governs. The pregnancy-rate contrast is structurally confounded: Ovsynch guaranteed insemination (82% inseminated) while CIDR cows were inseminated only if detected in oestrus (44%), so per-cow pregnancy rate mixes treatment effect with insemination opportunity; conception rate per inseminated cow (23.1% CIDR vs 18.3% Ovsynch, not significant) is the cleaner fertility contrast. Single herd.
Crane MB, Bartolome J, Melendez P, de Vries A, Risco C, Archbald LF. Comparison of synchronization of ovulation with timed insemination and exogenous progesterone as therapeutic strategies for ovarian cysts in lactating dairy cows. Theriogenology. 2006;65(8):1563-74. PMID: 16229884. Registry ID: none in the record. MeSH: Animals · Body Constitution/physiology* · Cattle · Cattle Diseases/therapy* · Dinoprost/administration & dosage/therapeutic use · Drug Implants/administration & dosage/therapeutic use · Estrus/drug effects*/physiology · Estrus Detection · Female · Gonadotropin-Releasing Hormone/administration & dosage/therapeutic use · Insemination, Artificial/veterinary · Lactation · Logistic Models · Ovarian Cysts/therapy/veterinary* · Ovulation Induction/methods/veterinary* · Parity · Pregnancy · Pregnancy Rate · Progesterone/administration & dosage/therapeutic use* · Random Allocation · Time Factors
Kim 2006: a CIDR-based timed-AI protocol gave a higher conception rate than a single GnRH injection with AI at oestrus (52.3% vs 26.9%, P < 0.05) in cows with follicular cysts
Randomised controlled trial (record states cows were randomly assigned; publication types: Journal Article, Randomized Controlled Trial)
Who: Dairy cattle: lactating dairy cows diagnosed with follicular cysts, randomly assigned in experiment 1 to a single GnRH injection at diagnosis (day 0) with AI at oestrus within 21 days (GnRH group, n = 70) or a CIDR-based timed-AI protocol (CIDR device plus GnRH on day 0, prostaglandin F2alpha at CIDR removal on day 7, GnRH day 9, timed AI 16 h later; n = 65). A second experiment compared follicular dynamics under the same CIDR-based protocol in cystic cows (n = 16) and normally cycling cows (n = 15).
Result: Conception rate after the CIDR-based timed-AI protocol was 52.3% vs 26.9% after AI at oestrus following a single GnRH injection (P < 0.05; absolute difference 25.4 percentage points; relative rate about 1.9). In experiment 2, follicular wave emergence, interval to wave emergence, dominant and preovulatory follicle diameters and ovulation synchrony did not differ between cystic and normally cycling cows under the CIDR-based protocol (P > 0.05). The authors concluded the CIDR-based timed-AI protocol results in an acceptable conception rate in dairy cows with follicular cysts.
Watch out: The comparison is confounded by design: the CIDR arm also received two GnRH injections and guaranteed timed AI, while the GnRH arm received one GnRH injection and depended on oestrus detection — so the 52.3% vs 26.9% contrast tests a whole management package, not progesterone vs GnRH, and it must not be quoted as a progesterone effect. The relative rate of about 1.9 sits inside the 0.5-2.0 band that is not, on its own, solid evidence. No resolution (cyst disappearance) outcome is reported in the abstract.
Kim IH, Suh GH, Kim UH, Kang HG. A CIDR-based timed AI protocol can be effectively used for dairy cows with follicular cysts. Anim Reprod Sci. 2006;95(3-4):206-13. PMID: 16288840. Registry ID: none in the record. MeSH: Animals · Cattle · Cattle Diseases/drug therapy* · Delayed-Action Preparations · Dinoprost/administration & dosage · Drug Implants · Female · Follicular Cyst/drug therapy/veterinary* · Gonadotropin-Releasing Hormone/administration & dosage · Injections/veterinary · Insemination, Artificial/methods/veterinary* · Progesterone/administration & dosage*
Kawate 2011: adding a CIDR to Ovsynch in 38 cows with cystic ovarian disease changed neither hormone concentrations nor conception rate significantly
Comparative study, allocation method not stated in the abstract (publication types: Comparative Study, Journal Article)
Who: Dairy cattle: dairy cows with cystic ovarian disease (a cystic follicle of diameter 25 mm or more without a corpus luteum, confirmed by two rectal palpations 7-14 days apart), treated with Ovsynch (GnRH day 0, prostaglandin F2alpha day 7, GnRH day 9, AI day 10; n = 15) or Ovsynch plus a CIDR from day 0 to day 7 (n = 23). Plasma oestradiol-17beta was measured on days 0, 7 and 9 and progesterone on days 0, 7, 9 and 17.
Result: Plasma oestradiol-17beta and progesterone concentrations on all days examined, and conception rates, did not differ significantly between the two timed-AI protocols. Cows with low oestradiol-17beta (below 2 pg/ml) on day 9 had lower progesterone concentrations on day 17 and lower conception rates (P < 0.05) than cows with high oestradiol-17beta (2 pg/ml or more), regardless of protocol. The authors conclude that, in dairy cows with cystic ovarian diseases, adding a CIDR to Ovsynch had no remarkable effects on hormone concentrations during or after treatment or on conception after timed AI.
Watch out: Very small (15 vs 23 cows) and the abstract reports no conception-rate figures at all — only that the difference was not significant — so this card supports 'no difference shown', not any effect size. The abstract does not state randomisation, so this card alone is design class (c). Cystic ovarian disease here required two palpations without a corpus luteum, a stricter case definition than the single-examination diagnoses in the other cards.
Kawate N, Watanabe K, Uenaka K, Takahashi M, Inaba T, Tamada H. Comparison of plasma concentrations of estradiol-17β and progesterone, and conception in dairy cows with cystic ovarian diseases between Ovsynch and Ovsynch plus CIDR timed AI protocols. J Reprod Dev. 2011;57(2):267-72. PMID: 21242655. Registry ID: none in the record. MeSH: Animals · Cattle · Delayed-Action Preparations · Estradiol/blood* · Female · Fertility Agents, Female/pharmacology/therapeutic use · Fertilization/drug effects* · Insemination, Artificial · Ovarian Cysts/drug therapy/veterinary* · Ovulation Induction/methods/veterinary* · Pregnancy · Progesterone/blood*
Abdalla 2020: in 552 cows with follicular cysts, CIDR-added regimens only tended to raise pregnancy per AI vs Ovsynch (odds ratios about 2.1-2.3, P = 0.07-0.09, not significant)
Nonrandomised single-herd protocol comparison (record's own wording; publication types: Journal Article)
Who: Dairy cattle: 552 cows in a single herd diagnosed with follicular cysts (follicular structures over 25 mm on two ultrasonographic examinations 7-10 days apart), assigned in a nonrandomised study to one of five ovulation-synchronisation protocols with fixed-time AI: Ovsynch; New-CIDR (Ovsynch plus a new CIDR insert days 0-7); Reused-CIDR (as New-CIDR with a previously used insert); G-New CIDR (a pre-GnRH 7 days before the New-CIDR regimen); and RG-Ovsynch (repeated GnRH every 7 days until a luteal structure was seen, then Ovsynch). Pregnancy per AI at days 30 and 70 was analysed by logistic regression.
Result: Compared with Ovsynch, RG-Ovsynch improved pregnancy per AI at day 30 (odds ratio 2.6, P = 0.03) and day 70 (odds ratio 2.5, P = 0.05). New-CIDR and G-New CIDR were associated with non-significant increases in pregnancy per AI at day 30 (odds ratio 2.1, P = 0.09 and odds ratio 2.3, P = 0.07) and day 70 (odds ratio 2.01, P = 0.09 and odds ratio 2.2, P = 0.09). Reused-CIDR was not associated with improvement (P = 0.93 and P = 0.79). RG-Ovsynch had a longer diagnosis-to-insemination interval (median 24 days). New and reused inserts produced comparable serum progesterone concentrations. The abstract reports odds ratios only — absolute pregnancy rates per protocol are not given in the record's abstract.
Watch out: Explicitly nonrandomised, so protocol groups may differ systematically, and the study's one significant result (RG-Ovsynch) is a GnRH-intensification strategy, not a progesterone strategy — it must not be quoted for the progesterone side of this shelf. The CIDR odds ratios (about 2.1-2.3) are non-significant (P = 0.07-0.09) and come without absolute rates in the abstract, so no absolute benefit can be stated from this record.
Abdalla H, de Mestre AM, Salem SE. Efficacy of ovulation synchronization with timed artificial insemination in treatment of follicular cysts in dairy cows. Theriogenology. 2020;154:171-180. PMID: 32622197. Registry ID: none in the record. MeSH: Animals · Cattle · Cattle Diseases* · Dinoprost/pharmacology · Estrus Synchronization · Female · Follicular Cyst*/veterinary · Gonadotropin-Releasing Hormone · Insemination, Artificial/veterinary · Ovulation · Pregnancy · Progesterone
Synthesis: no demonstrated pregnancy-rate advantage for either GnRH-based or progesterone-based cyst therapy — MAYBE (weak evidence)
Synthesis
Who: Synthesis of the four cards above (Crane 2006, 401 cows; Kim 2006, 135 cows; Kawate 2011, 38 cows; Abdalla 2020, 552 cows) and of the near-miss record documented in the result, fetched at drafting and deliberately not carded as a claim-carrier.
Result: (1) Resolution/cyclicity: the only carded resolution-type outcome, corpus luteum on day 21 in Crane 2006, was 83% (Ovsynch) vs 79% (CIDR), P > 0.05 — no difference shown. (2) Pregnancy/conception: Crane found no significant difference in conception (18.3% vs 23.1%) or pregnancy rate (14.4% vs 9.5%); Kawate found no significant conception difference when a CIDR was added to Ovsynch; Abdalla's CIDR-added regimens were non-significant tendencies only. The single significant pro-progesterone result (Kim: 52.3% vs 26.9%) compares a CIDR-based timed-AI package against a single GnRH injection with oestrus-detection AI, so it cannot isolate progesterone. (3) Near-miss not carded: Ambrose 2004 (PMID: 15600159), an observational study of GnRH plus prostaglandin with (8 cows) or without (18 cows) a CIDR, reported a 41% pregnancy rate after synchronisation and timed AI in the without-CIDR trial and follicular responses in both, but no comparative pregnancy rate for the CIDR arm — it cannot carry a comparative claim. (4) Design class (b) for the shelf (randomisation established by Kim 2006; blinding not established in any carded record), with Crane class (c) on alternate allocation and Abdalla nonrandomised, as flagged on their cards. Tier C is not engaged.
Watch out: One-home check at drafting: none of PMIDs 16229884, 16288840, 21242655, 32622197 or 15600159 appears in any other pack on disk. Case definitions differ across cards (single palpation/ultrasound diagnosis in Crane and Kim; two examinations without a corpus luteum in Kawate and Abdalla), and 'pregnancy rate' denominators differ (per cow treated in Crane; per insemination in Kim) — do not pool the percentages across cards.
Synthesis of Crane MB et al. PMID: 16229884; Kim IH et al. PMID: 16288840; Kawate N et al. PMID: 21242655; Abdalla H et al. PMID: 32622197; Ambrose DJ et al. PMID: 15600159. Registry IDs as on the individual cards (none in the records).
Back to the library index · VetMed home
VetMed is an educational resource, not veterinary advice.