Collection Procedure

Several methods of semen collection have been discussed in the previous sections, the majority of which involve the use of an AV. The procedures for the correct use of an AV are varied and depend on the type of AV being used and individual stallion preference. Regardless of the specific techniques that are chosen, the following principles apply to the collection procedure.

The aim when using an AV is to mimic the natural vagina and it is important that, among other things, the positioning of the AV during collection is appropriate. After teasing (Fig. 5.23) the stallion should be allowed to approach the jump mare or dummy. The collection procedure, whether using a jump mare (Fig. 5.23) or a dummy (Fig. 5.24), will be very similar, except that fewer handlers are required in the case of the dummy as only the unpredictable behaviour of the stallion needs to be catered for. As with natural covering, all handlers (and the collector) should be positioned on the same side of the stallion (Fig. 5.23). This is normally the nearside, as it is the side most stallions are used to, but it depends on the preference of the collector. The positioning of all handlers on the same side when using a jump mare means that, in the event of an accident or should problems occur with the procedure, both the mare's head and the stallion's head can be pulled to the same side as the collector. This action will ensure that the hindquarters of the mare and stallion are moved away from each other and the collector. This reduces the risk of injury to all parties, especially as a result of lashing out by either the mare or the stallion. Collection from the offside is perfectly

Stallionpenis

Fig. 5.23. Events involved in semen collection using a jump mare: (a) introduction or teasing of the stallion and mare; (b) AV ready for use; (c) guiding the stallion's penis into the AV and the correct positioning of the handlers all on the same side of the mare and stallion; (d) slightly inclined positioning of the AV to mimic the natural position of the mare's vagina; (e) dismount of the stallion and slow removal of the AV, ensuring all semen is collected; (f) after dismount the stallion should be turned away from the mare to reduce the chance of injury; (g) the collected sample. (Photographs by Julie Baumber and Victor Medina.)

Fig. 5.23. Events involved in semen collection using a jump mare: (a) introduction or teasing of the stallion and mare; (b) AV ready for use; (c) guiding the stallion's penis into the AV and the correct positioning of the handlers all on the same side of the mare and stallion; (d) slightly inclined positioning of the AV to mimic the natural position of the mare's vagina; (e) dismount of the stallion and slow removal of the AV, ensuring all semen is collected; (f) after dismount the stallion should be turned away from the mare to reduce the chance of injury; (g) the collected sample. (Photographs by Julie Baumber and Victor Medina.)

Stallion Penis
Fig. 5.24. Collection from a stallion using a dummy mare. (Photograph by Julie Baumber and Victor Medina.)

acceptable, provided the handlers are appropriately placed. Indeed, collection from the offside is preferred by some stallions and by many right-handed collectors, especially with the heavier Cambridge type AVs, as it allows the right arm to take the weight of the AV. In Germany, specially designed bridles are used that allow the handler to stand on the nearside and the collector on the offside. The reins of the bridle are so arranged as to allow the handler to pull the horse's head to the right in the event of problems (J.M. Parlevliet, The Netherlands, 1998, personal communication; S. Revell, Wales, 1998, personal communication). Many dummies are fitted with a lumen into which the AV may be placed (Fig. 5.19), so circumventing the problem as to on which side to stand. Once the stallion is drawn and ready to mount the mare, he should be allowed to do so with minimal interference. Excessive interference at any stage, but especially during the period prior to intromission and ejaculation, can discourage or distract the stallion. If the interference is consistently a problem it will result in psychological effects, reducing libido and willingness to use an AV.

Once the stallion has mounted he should be allowed a little time to stabilize himself on the mare or dummy. The collector then steps forward and deflects the penis away from entry into the vagina and into the AV (Fig. 5.23c). The amount of time allowed for a stallion to stabilize himself should not be too long and the collector should be ready to deflect the penis immediately on mounting if there is any danger of the stallion entering the mare or injuring himself on the dummy. Once the AV has been placed over the penis (Fig. 5.23d), the warmth within it plus the thrusts of the stallion should stimulate ejaculation. It may be necessary to reduce the pressure within the AV on entry by allowing some water or air to escape. This is not normally required in stallions used regularly for collection as the required pressure within the AV can be predetermined. However, in new stallions, depending upon the ease with which they thrust and the size of the stallion, a reduction in the AV pressure may be deemed necessary.

During thrusting and subsequent ejaculation, the AV should be slightly inclined at an angle of 25° to the horizontal, equivalent to the natural angle of the mare's vagina, at about mid hip level of the mare (Fig. 5.23d). One hand should hold the handle of the AV while the other supports it from below. The AV should be held in this position, the collector's hips and ribs pushing it against the mare's side, but allowance should be made so that the AV can move slightly as the stallion thrusts. During ejaculation some stallions may grasp the mare or dummy to steady themselves; others may require their legs to be held in place on the mare or dummy, especially if they are small in comparison. This can be done by the mare handler, provided the mare is quiet and happy to stand still.

Successful ejaculation is normally marked by the flagging of the stallion's tail. It can be more accurately confirmed by sliding the hand (which is supporting the AV) along the length of the AV to the base of the penis and feeling for rhythmical contractions of the urethra along the ventral side of the penis. This technique accurately determines whether ejaculation has taken place but the interference may be objected to by some stallions. Immediately ejaculation has been ascertained, the distal end of the AV, with the collecting vessel, should be slowly lowered to aid the collection of semen into the collecting bottle (Fig. 5.23e). During this stage the stallion may dismount. If possible, the AV should remain on the stallion's penis and be slowly lowered to the vertical as his erection subsides. This may not be possible with all stallions but the AV should remain on the penis as long as possible to ensure maximum collection of the ejaculate. Once the AV is removed from the penis, the urethral area may be observed for the presence of a white frothy secretion - a further indication that ejaculation has taken place.

As soon as the AV has been removed and ejaculation confirmed (Fig. 5.23f), the collector should move away from the stallion, holding the AV vertically (Fig. 5.23g). The filler cap should be unscrewed to allow water to drain out and so reduce the pressure within the lumen and encourage any semen deposited towards the entrance of the AV to drain into the collecting vessel. Drainage of the water will also cool the AV and so minimize the risk of overheating of the spermatozoa from excessive contact with the warm lumen environment (J.M. Parlevliet, The Netherlands, 1998, personal communication). Once all the semen has been collected, the collecting vessel should be removed from the AV and taken without delay to an incubator or water bath in the laboratory.

When the stallion has dismounted, the mare should be brought forward and turned towards the handler; the stallion should similarly be turned towards the handler at the same time. This minimizes the risk of injury to both animals and handlers. After collection the stallion does not normally require washing, as his penis should not have come into direct contact with the mare, and so he may be returned directly to his stable or field.

The exact procedure involved in collection may vary from stallion to stallion. Many have certain idiosyncracies and may perform better if these are catered for. As with all stud management, knowledge of the stock being handled helps significantly in obtaining good and consistent results.

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