Stallion Dismount Latency and Pregnancy Outcomes in Thoroughbred Horses In Thoroughbred natural service breeding, dismount semen — residual urethral semen collected after copulation — is routinely used as a proxy for ejaculate quality. This study investigated whether the duration a stallion remains mounted post-ejaculation (stallion dismount latency) influences both dismount sample composition and pregnancy outcomes. Study Design: 62… Read More »
Storage Conditions Affecting Prolonged Storage of Post-thaw Semen Field-based use of cryopreserved stallion semen is often limited by the equipment and expertise required for on-site thawing. Thawing centrally, then achieving prolonged storage of post-thaw semen and shipping it in a cooled state could simplify artificial insemination programs at locations remote from the laboratory or center, but optimal post-thaw… Read More »
Timing Protocol Modification for Frozen Semen Insemination in Mares There are in use a variety of protocols for frozen semen insemination. This research compares the results from several currently used with those from a new timing protocol. Background: There is a growing demand for use of frozen semen in equine artificial insemination practices Classic protocols rely on time-intensive… Read More »
Is there a Seminal Plasma Impact on Foal Growth? This study investigated the downstream developmental consequences of seminal plasma (SP) exposure — or its absence — at the time of breeding, examining both placental gene expression and seminal plasma impact on foal growth trajectories over the first two years of life. Background & Purpose: SP proteins serve key… Read More »
The Effect of Uterine Interference on Reproductive Function in the Mare An unpublished manuscript written in 1976 by John R Newcombe and W E Allen, Royal Veterinary College University of London Introduction It has been shown in several recent reports that irrigation or infusion of the uterine lumen of the mare during the luteal phase of the oestrous… Read More »
US CEM Outbreak – Update The CEM outbreak in Florida continues to produce new cases. The initial animal was a mare identified following breeding in May. Tracebacks commenced and to date there are a total of 43 cases, which include 16 domestic ponies (2 stallions, 1 mare, and 13 geldings), 14 riding horses of various breeds (all geldings),… Read More »
Unpublished Research Articles from Professor John Newcombe, BVetMed, MRCVS We were delighted – honoured to be asked – to present some previously unpublished and summarized research articles from Professor John Newcombe. The author is a world-renowned expert in the field of equine reproduction, with a list of peer-reviewed published works well in excess of a hundred. In association… Read More »
Repeated Embryo Loss in Mares is the Result of Retarded, Small for Age, Embryonic Vesicles. By Professor John Newcombe, BVetMed, MRCVS A Normal Foetus and then a Foal Will Eventually Result When a Normal Embryo is Produced: A Case Report ABSTRACT A twelve-year-old maiden/barren part-TB mare with otherwise limited reproductive history, was sent to an equine fertility clinic… Read More »
CEM Identified in Florida “A mare in Florida (FL) has been confirmed culture positive by the USDA APHIS National Veterinary Services Laboratories (NVSL) for Taylorella equigenitalis, the bacterium that causes contagious equine metritis (CEM). The affected mare, the breeding stallion, and one other mare are under quarantine. A comprehensive epidemiological investigation is being conducted including traceback and history… Read More »
The last completed cycle (IOI) of the year before a phase of extended winter anoestrus is significantly longer than the midsummer IOI in each mare By Professor John Newcombe, BVetMed, MRCVS Abstract Data held at a Clinic at latitude 52°N was examined retrospectively to determine the length of the last Inter-ovulatory Interval (“IOI” – “cycle”) preceding a period… Read More »
