Juvenile and older males entering a new career as a breeding stallion don't have the luxury of a changing cascade of hormones or an event like parturition to jumpstart their innate nature to show them how to be a stallion. There is likely only a change in routine, location, or in their training schedule that cues them into their new roles as breeding animals. Many stallions make the transition seamlessly. Simply acting on the behavior they have been trying to use for years, allowing their behavior to mimic their springtime rise in testosterone. When exposed to a female, they have little doubt about the job at hand and will readily take to live cover or phantom training. Additional information for training the young stallion for collection can be found in our article, Collecting Semen from the Young Stallion. However, for some, the transition proves far more difficult and oftentimes frustrating for the stallion and for the staff at the shed.
Nervous, timid, slow starting, shy, and anxious, are all terms used to describe stallions that are slow to make the transition to breeding. Their lack of stallion-like behavior may be a conditioned response from years of training, fear of correction if they do show stallion-like tendencies, and anxiety or fear of acting like a stallion. These stallions can show a lack of interest, lack of normal stallion behavior, failure to obtain an erection, or inappropriate behavior in the presence of a female. The slow starting stallion shows minimal behavioral interest in a mare in heat whether it be mares in natural estrus, programmed mares, or ovariectomized mares under the influence of exogenous estrogen.
Slow starting stallions will quietly move around the estrus mare, possibly with a flaccid dropped penis, but not necessarily. They may play with the mare’s tail, lick her flank, and/or rest their head on her croup. Some may mount a mare with a flaccid penis or without dropping at all. A Flehmen response is variable in these horses. However, any behavioral act that is “stallion like” in nature should never be corrected but should instead be reinforced and rewarded.
What makes these slow starting stallions even more frustrating are the normal values for testicular size/mass, testosterone, estrogens, and pituitary derived signaling hormones that don't allow a clinician to find any abnormality to or deficiency to treat or stimulate using medication. Oftentimes, these slow starting stallions will be seen in their stalls with erections including masturbation. If the drippings or discharges are collected, viable, motile, and highly concentrated sperm are in the samples.
So what can we do to correct these slow starting stallions and give them the tools and confidence to become a normal breeding stallion? Diagnostically, we must make sure there is nothing physically or hormonally wrong with stallion. This includes a thorough Stallion Breeding Soundness Exam which includes imaging of the reproductive organs, hormone profiles, physical exam, lameness exam, history of any medication, and paying close attention to historical activities of the stallion. Once we rule out any underlying medical issue, we can begin to work on the behavioral issues that may prevent a stallion from being collected.
Many times, the process of reconditioning a stallion to breeding behavior begins with numerous and short trips to the breeding shed. There are several things we do during training sessions:
- Utilize mares of varying age, color, estrus stage (early, mid, and late estrus)
- We may take the stallion outside the shed for a brief walk
- Try different sides of the mare
- Leave everything as natural as possible
- Give both the mare and stallion long leads without correction so they can play off each other’s natural mating cues
In general, as soon as progress is made in a positive direction, the stallion is rewarded with praise and the session ended. We try to be as patient as possible and never get to a point where the stallion exhibits frustration or boredom.
Unfortunately, there is limited pharmaco-therapy that helps fix these “slow” stallions since most of the problem is a behavioral issue. I am very diligent in making sure lameness and/or musculo-skeletal pain is not an issue. If I feel anxiety in the shed is hampering progress, I may try very low doses of anti-anxiety medication administered a few minutes prior to collection to see if improvement is noted. Lastly, we may put these stallions on low doses of GnRH or topical testosterone cream to increase the libido at or near the time of collection. I am very cautious regarding the duration of therapy with testosterone applications for several reasons. One is because if you over utilize exogenous testosterone it can cause the down regulation of endogenous testosterone. Also, it is possible for staff and handlers to be affected by the gels and creams if there is transfer to their skin. However, low doses of GnRH have been administered to stallions for long durations of therapy with no adverse effects.
Another factor to consider is how the “slow” stallion is housed. Just as there is an “alpha” mare in the broodmare band it has been shown there is also a hierarchy between stallions housed in close proximity to one another. For some stallions, this can result in low testosterone. If we believe this could be a factor for a particular stallion we will house him next to or in close proximity to a stable group of mares. However, even the closeness of one mare can show improvement in the stallion’s behavior. Sometimes this can assert his natural desire to have a harem of mares as he expresses his dominance over the band of mares.
In any case, a quick fix to these difficult slow starting stallions is not usually achieved. With enough time, and more importantly patience, most of these stallions will make strides to become active breeding horses.