Reproductive performance of dairy cows with ovarian cysts after different GnRH and cloprostenol treatments F. Lo Âpez-Gatius a,* , M. Lo Âpez-Be Âjar b a Departamento de Produccion Animal, Escuela Te Âcnica Superior de Ingenierõ Âa Agraria, Universidad de Lleida, Avda. Alcalde Rovira Roure 177, 25198 Lleida, Spain b Department of Veterinarian Anatomy and Embryology, Autonomous University of Barcelona, Barcelona, Spain Received 1 October 2001; accepted 14 February 2002 Abstract Cysticovariandiseaseisanimportantcauseofreproductivefailureandeconomiclossforthedairy industry. This reportdescribes two consecutive studies. The objective of the ®rst was to evaluate the responseofcowswithovariancyststotwotherapeutictreatments.Inthesecondstudy,wecomparedthe effectivenessofthebesttreatmentestablishedinStudy1withthatoftheOvsynchprotocol.ForStudy1, cowswereconsideredtohaveanovariancystifitwaspossibletoobserveasinglefollicularstructure withafollicularantrumdiameter 25mmintheabsenceofacorpusluteuminthreeultrasonographic examinations performed at 7 days intervals. At diagnosis (Day 0), cows were assigned to one of two treatmentgroups.CowsinGroupGnRH/CLP(n  31)weretreatedwith100 mgGnRHi.m.and500 mg cloprostenol(CLP)i.m.onDay14.CowsinGroupGnRH±CLP/CLP(n  32)weretreatedwith100 mg GnRH i.m. plus 500 mg CLP i.m. on Day 0, and 500 mg CLP i.m. on Day 14. The animals were inseminatedatobservedestrusandmonitoredweeklybyultrasonographyfor4weeksoruntilAI.Cows intheGnRH±CLP/CLPgroupshowedalowercysticpersistencerate(15:6% < 45:2%; P  0:01);a higherestrusdetectionrate(84:4% > 41:9%; P < 0:0001);ahigherovulationrate(75%versus32.3%; P < 0:0001) and a higher early response rate (31% > 3%; P  0:02) than those in the GnRH/CLP group. For the second study, 128 cows with ovarian cysts were randomly assigned to one of two treatment groups: cows in Group Ovsynch (n  64) were treated with 100 mg GnRH i.m. on Day 0, 500 mgCLPonDay7,and100 mmGnRHi.m.36hlater.Cowsinthisgroupwereinseminated24hafter the second GnRH dose (Ovsynch protocol). Cows in Group GnRH±CLP/CLP/GnRH (n  64) were treatedasthoseintheGnRH±CLP/CLPgroupofStudy1butreceivedGnRH32hafterthesecondCLP treatment and were inseminated 24h after this. A further group of cows without ovarian cysts inseminated at natural estrus served as the Group Control (n  64). Cows in the GnRH±CLP/CLP/ GnRHgroupshowedalowercysticpersistencerate(10:9% < 46:9%; P < 0:0001);higherovulation Theriogenology 58 (2002) 1337±1348 * Corresponding author. Tel.: 34-973-702-500; fax: 34-973-238-264. E-mail address: flopez@prodan.udl.es (F. Lo Âpez-Gatius). 0093-691X/02/$ ± see front matter # 2002 Elsevier Science Inc. All rights reserved. PII:S0093-691X(02)00952-4