The artificial vagina used for the bull is the template for that is used on most of the small ruminants. The sheep AV as well as that of the goat and deer are simply smaller versions of the bull AV.
A piece of PVC pipe is the main body of the bull AV. This usually has a sizable hole drilled in the side roughly 10 cm from the end for water venting when the bull thrusts. In this pipe fits a rubber liner, which is folded back over at each end to create a space between the liner and the pipe. This space is filled with warm water to create friction and pressure as well as a warm temperature to simulate a real vagina. The end of this is secured with rubber bands to prevent it from coming open and thus possibly contaminating the sample with water. The hole at the end of the pipe is covered over by the excess inner lining that has been folded over the end of the tube. The rubber band at this end of the tube is above the hole such that water will not come out around the end of the pipe, but will be able to escape through this hole if enough pressure is applied. The outside of the tube can be covered by an additional liner which holds the displaced water inside of it preventing the spray of water that is otherwise associated with the bull thrusting. The end opposite the hole in the pipe is fitted with a rubber collection cone. At the end of this cone a graduated vial is attached to receive the sample of semen. All attachments are secured with rubber bands. It is important to be aware of the location of the rubber bands after collection; bands should be counted after collection to make sure that none remain on the bull's penis.
An example of a fence system used to restrain bulls.
A bull can be stimulated using a cow, steer or another bull as a teaser animal. Any one of these can also be used as the mounting animal, or a dummy can be used. To get highest results in this area it is preferable to have the bull false mount once or twice and then allow him to mount to completion. It is important to have proper facilities when collecting from a bull. A restraining box using 3-inch steel piping is a preferred set up so that the animal being mounted is restrained by more than merely a lead rope. This is especially important when another male or a non-estrous female is being used because these animals in particular are likely to be adverse to the concept of being mounted. In addition it is important to take caution in general when working with bulls because they are large animals and can be unpredictable and therefore dangerous. As with all the other quadrapedal species, bulls can be trained to mount a dummy instead of a live animal for the purpose of collection. The AV should be well lubricated and warmed to approximately 45 degrees. An insulated jacket is useful in keeping the collection vial warm so as to prevent cold shock. The AV should go on the penis as the bull begins to mount and removed as the bull dismounts. When inserting the bull's penis into the AV it is important to grasp the sheath instead of the penis itself, lest the bull subsequently prematurely ejaculate. It is also desireable to, before hand, clip the area surrounding the bull's penis and wash out with water or a mild soap solution to remove various debris from the sheath.
The two larger electrodes in this picture are designed for the bull.
Electroejaculation is a method that is used in bulls, however only in cases of debilitated animals or those that are incapable due to age. In general, this is a satisfactory method of obtaining an ejaculate. The voltage required to stimulate the nerves is low enough that the bull does not feel pain and only perhaps a mild amount of discomfort. Occasionally the voltage will affect the leg muscles of the bull, causing them to stiffen and the bull will go down. Because of this possibility it is prudent to give the bull good footing and even a support under his chest. The ejaculate resulting from this method usually has a lower concentration of sperm, but the overall numbers are comparable to service to an AV. This is because stimulation of the sex glands causes a greater release of seminal fluid than occurs during a natural ejaculation.
The AV and techniques used for the bull are all completely applicable to the water buffalo as well which is something that is more useful in southeast Asia, but is of interest none the less.
