Select Sires

Proper Semen Placement in the Reproductive Tract
Transcript of Select Sires' Reproductive Moment Program
on DairyLine Radio Which Aired June 27, 2002

Maintaining maximum fertility in your A.I. program is a function of quality semen deposited in the proper place in the reproductive tract at the proper time relative to ovulation. Today we’ll key in on the issue of semen placement. Most A.I. organizations recommend the uterine body as the site for semen deposition. However, from time to time the question of horn breeding arises, wherein half the semen dose is deposited deep in each uterine horn. The theory is that semen deposition closer to the site of fertilization will improve the efficiency of sperm transport and fertility. However, research projects comparing horn and body breeding have failed to consistently come up with the same answer. While no study has ever suggested the fertility of horn breeding to be less than that of body breeding, a positive response to horn breeding appears to be dependent on the proficiency of the body breeding technique. In a Select Sires study, non-return rates of below average technicians were significantly improved by horn breeding, while above average technicians was not affected. Other studies have found that, in most cows, comparable numbers of sperm gain access to both oviducts even after depositing all the sperm deep in only one uterine horn. When I put all horn breeding studies in a basket and try to come up with a single consistent answer, I get something like this; the most important aspect of semen placement is to be sure you are getting through the cervix. If your target is the uterine body and you’re not sure of your exact gun tip location, lean towards going too far and depositing semen in a uterine horn. This will be less likely to compromise fertility than falling too short resulting in cervical deposition. Beyond that, horn breeding simply improves our confidence that we are in fact penetrating the cervix. However, because this procedure takes more time, increases the risk of uterine trauma, and will likely increase the probability of abortion if previously inseminated animals are inadvertently re-inseminated, only experienced technicians should consider adopting the deep uterine horn breeding technique. If you would like more information on semen deposition, site of insemination, don’t hesitate to contact your local Select Sires Reproduction Solutions™ specialist.

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Copyright 1996-2002 Select Sires Inc. Last updated 15-Jul-2002.

Select Sires Inc., 11740 U.S. 42 North, Plain City, Ohio 43064 / Phone: (614) 873-4683 Fax: (614) 873-5751