Welcome to The Select Breeders Blog

The Major Causes of Damage to Sperm During Freezing…water and salts and ice, oh my!

Posted by Paul Loomis on Tue, Nov 14, 2017 @ 01:10 PM

I have always been fascinated by the exquisite design of biological systems. The more we humans understand about biology, the more we realize we don’t know. The process of mammalian fertilization is one of these complex biological systems that in nature requires the proper coordination of so many factors ranging from the behavior of male and female to biochemical changes at the cellular and molecular level. Defined as: “A process in sexual reproduction that involves the union of male (sperm) and female (ovum) gametes (each with a single, haploid set of chromosomes) to produce a diploid zygote”, fertilization requires that functionally viable sperm, at the right stage of maturity, are present in the oviduct of the mare during a brief window of time when a functionally viable oocyte is present.

Read More

Tags: Frozen Semen

Trends in Equine Assisted Reproduction

Posted by Dr. Ed Squires on Mon, Oct 09, 2017 @ 09:31 AM

It has been almost 20 years since I started an assisted reproduction program at Colorado state University. The purpose of that program was to develop techniques to preserve equine genetics. It is beyond the scope of this article to discuss all the goals of that program but I would like to focus on production of foals from old mares and stallions via in vitro technology (aka test tube horse).

Read More

Tags: Assisted Reproduction Techniques

Shuttle Stallions - Frozen Semen to the Rescue

Posted by Erin Bishop on Wed, Jul 05, 2017 @ 01:21 PM

Shuttle or Dual-Hemisphere Stallions are terms used to describe breeding stallions which travel between the Northern and Southern Hemispheres for their respective breeding season. Several questions arise when discussing shuttle stallions and may include: Why do stallion owners incur the costs and risks of sending their stallions thousands of miles away? Does the lack of sexual rest affect their fertility? Is there a way to service mares in a different hemisphere without sending the stallion so many miles away?

Read More

Tags: Frozen Semen, Stallion Management

Equine Seminal Plasma: The Good, The Bad and The Ugly

Posted by Paul Loomis on Mon, May 15, 2017 @ 01:21 PM

To understand why seminal plasma is beneficial in some situations and potentially harmful in others we must first review what it is, where it comes from and what we think are its roles in reproduction. The term seminal plasma refers to the fluid portion of ejaculated semen in which the spermatozoa are suspended. This fluid consists of secretions from the accessory sex glands in the stallion’s reproductive tract. These include the ampullae, the vesicular glands (seminal vesicles), the prostate gland and the bulbourethral glands (figure 1).

Read More

Tags: Frozen Semen, Stallion Management, Mare Management, Breeding With Frozen Semen

Analysis of Frozen-Thawed Equine Semen

Posted by Julie Skaife on Thu, Apr 13, 2017 @ 09:36 AM

Once equine semen is frozen it is recommended that a post-thaw analysis be performed in order to ascertain the semen quality. There is variability in how well sperm from different stallions respond to the cellular stress of freezing and thawing. It is important to determine how well the sperm from a particular stallion withstood the stress of cryopreservation in order to make informed decisions regarding the management of their frozen semen inventory and breedings. Also, when we freeze a stallion for the first time we do a test freeze comparing several different protocols. We then use the post-thaw motility to select the freezing protocol for subsequent collections which gives the best post-thaw result. There are industry recommended minimums for commercial distribution of equine frozen semen and therefore it is pertinent to know if your stallion’s frozen semen would qualify. Consequently, the analysis of frozen-thawed semen is a valuable tool for the semen freezing lab, but also for the veterinarian receiving the semen. Your vet may base the breeding management of your mare upon the post-thaw quality of the semen. Also, many vets take a look at the motility of the frozen semen at the time of insemination, for future reference if there are concerns should the mare not check in foal.

Read More

Tags: Frozen Semen, SBS Semen, Breeding With Frozen Semen

Is the Volume of the Inseminate Important for Fertility?

Posted by Dr. Ed Squires on Sun, Mar 12, 2017 @ 08:29 PM

A common question asked by many breeders is whether the volume of semen deposited into the mare affects fertility. When a mare and a stallion mate naturally the entire ejaculate is deposited into the mare. This volume is usually 50 ml or more and includes several billion sperm. However, when breeding mares using artificial insemination, good fertility can be achieved with as little as 1/2 ml of semen. I have been telling breeders for years that the volume of the ejaculate is not important as long as the stallion is producing good sperm numbers. For example, a stallion can produce 8 billion sperm with 80 ml of semen at a concentration of 100 million sperm/ml or 20 ml of semen at a concentration of 400 million sperm/ml. Volume of the ejaculate and concentration are inversely related (i.e. if volume goes up then concentration goes down).

Read More

Tags: Mare Management

Equine Embryo Biopsy

Posted by Dr. Phil Matthews on Tue, Feb 07, 2017 @ 10:14 AM

One of the advantages of embryo transfer is the ability to biopsy the embryos in an attempt to diagnose different genetic traits or determine gender. The ability to do so has existed for several years and the amount of genetic information that can be realized is ever expanding as geneticists learn more and tests become available to identify particular alleles.

Read More

Tags: Embryo Transfer

Oxytocin Use in the Mare

Posted by Dr. Dave Scofield on Sun, Jan 08, 2017 @ 08:15 PM

Oxytocin is one of the most utilized hormones in broodmare practice. With so many possible clinical applications, a review of the use of oxytocin in the mare highlights the benefits of oxytocin, as well as necessary precautions with its use. Oxytocin is a nine-amino acid neuropeptide that is produced in the hypothalamus and released by hypothalamic neurons that terminate in the posterior pituitary. It is released in a natural pulsatile manner and exerts its effects by coupling with oxytocin receptors on various tissues such as the endometrium, myometrium, heart, kidney, pancreas, and fat tissue. There are also local effects of oxytocin and receptor binding, notably in the utero-placental tissues that help to increase the effect and intensity of pituitary derived oxytocin pulses. Clinically, oxytocin is available as a sterile injection, 20 IU (international units) per milliter. It can be administered intravenously or intramuscularly.

Read More

Tags: Mare Management

Ways to Determine Equine Fetal Gender

Posted by Dr. Anna Toenissen on Mon, Dec 12, 2016 @ 01:13 PM

Horse breeders are always interested in the well being of their broodmares as well as the well being of the fetus they are carrying. Advances in reproductive techniques have made it possible to gain insight into how the fetus is progressing as well as the ability to determine its gender. Knowing whether a mare is carrying a colt or a filly can help owners make important decisions concerning their herds and the industry in general. For example, fetal sex determination is used on a regular basis among thoroughbred breeders prior to stock auctions. In this article, we discuss the sorting of equine sperm for sex as well as fetal sex determination via transrectal and transabdominal ultrasound.

Read More

Tags: Mare Management

Suppression of Stallion and Mare Behavior

Posted by Dr. Ed Squires on Sat, Nov 12, 2016 @ 01:30 PM

Once young colts and fillies reach the age of puberty their behavior may become an issue in the show ring or on the race track. Castrating a colt which you intend to use for breeding purposes may not be an option and mares are not typically permanently sterilized. Their sexual behavior may also cause problems with housing, trail riding, etc. In this article, Dr. Ed Squires discusses some of the common ways stallion and mare owners suppress the behavior of their horses.

Read More

Tags: Stallion Management, Mare Management