The importance of using the boar both in heat detection and when inseminating the sow has been widely confirmed by numerous studies and verified in the field: direct contact between the male and female (sight, smell, and sound) improves reproductive performance.
The correct implementation of this management practice depends on the type of sow housing at the time of mating: if they are housed in groups, the boar is introduced directly into the pen, or into an adjacent pen separated by a barrier, while if they are housed in individual pens, the boar is walked in front of the sows that are to be stimulated or inseminated. Generally, a docile boar is trained to be easily led back and forth through the aisles between the sows.
In rooms of a certain size with several intersecting aisles, panels or gates are required to form a route the boar has to follow between the various rows of crates that the boar must walk between the sows before returning to his own pen.
This is where a smart farmer has seen fit to equip the aisle intersections with a modular, length-adjustable gate that can be easily attached to all the corners of the crossings and the ends of the aisles, which are already equipped with special hooks for the gate.
It is made as shown in the photos, with two vertical stainless steel uprights, to each of which six horizontal tubes of suitable thickness are welded: those on one side have a smaller diameter than those on the other, so that they fit into each other and can slide telescopically. In this way, you have a sturdy, adjustable, convenient door that can be quickly attached to the corresponding mounting fixtures.
And... believe me, it's really practical, perhaps a little heavy, but very functional.