Biomedical subjects

Paul R Loomis

Publications and source records attributed to Paul R Loomis.

2 recordsLinked to original sources

PubMed2006

Advanced methods for handling and preparation of stallion semen.

Clinical reproduction in the horse more closely parallels human clinical reproduction than in other domestic farm animals. Horse breeders rarely include fertility as a selection criterion when making mating decisions; in most breeds, there is no licensing or approval of stallions. This has led to a significant number of stallions in the breeding pool that possess desirable performance traits but are subfertile for a variety of reasons, some of them genetically transmitted between generations. Therefore, semen characteristics can vary greatly among stallions within the breeding population. A champion stallion is not gelded or culled for poor semen quality or the inability of his spermatozoa to withstand semen preservation techniques. Rather, equine theriogenologists go to great lengths to maximize reproductive performance using any and all means available. Therefore, advanced methods for processing and selecting stallion semen provide the clinician with valuable tools for handling poor-quality semen or for obtaining spermatozoa for assisted reproduction procedures.

Animals↗

PubMed2005

Frozen semen management in equine breeding programs.

Success with frozen semen requires attention to detail and a basic understanding of the techniques for properly handling and thawing and inseminating frozen semen. Practitioners should also be familiar with strategies used for managing mares for insemination with thawed semen. This manuscript will review those techniques and also present fertility data collected in a commercial setting. Factors that affect pregnancy rates for mares inseminated with frozen-thawed semen such as timing and frequency of insemination were examined for two separate data sets consisting of 332 and 536 mare cycles collected during the 2002 and 2003 breeding seasons. There were no differences observed in pregnancy rates for mares inseminated once or multiple times in a given cycle (51.5% versus 51.7% for data set 1 and 47.1% versus 46.1% for data set 2). Mares inseminated twice on a cycle, once before and once after ovulation, became pregnant at a rate similar to mares inseminated once within 6h post-ovulation (48.1% versus 47.3%).

Aging↗