There is the possibility of captured guns being used, though I don't know of any instances. It is important to note that the difference in caliber between nations, and even individual platforms, would make using a captured gun reliant on how much ammunition was also captured. Also, while relatively similar in principle, time would be needed to learn the newly acquired system before it could be used effectively.

As far as field guns, which would likely have had a higher chance of capture because of their proximity to the front due to shorter range, the U.S. entered the war with a limited amount of 3-inch guns, which were mostly later replaced with 75mm guns of French origin (the French relied so heavily on this design/caliber that they almost entirely neglected larger/heavier calibers, costing them dearly in the opening years of the war). Britain made us of a 3-inch, eventually upgrading to a 5-inch later on in the war. Germany made effective use of 77mm guns, and eventually upgraded to 100/105mm.

All of this made the logistics of arming your own artillery corps (which may consist of different calibers/models within the same battalion) let alone an allies guns, a daunting task to begin with. Adding the ability to arm captured enemy guns just wasn't largely feasible unless a stockpile had been captured along with them.

Hey,

World War I, on the western front, is best known for the trench war it involved. Hundreds of kilometers of entrenchements manned by thousands of soldier. Enemy trenches being several hundred meters away from one another at the lengthiest, it was a complete shooting war.

With great improvements to aiming, batteries from both sides on the western front, had enough range to hit targets many kilometers away. These batteries, being extremely precious to the eyes of both commands, were thus positionned quite away from the front line.

Many deadly and inefficient assaults were made by both sides on each others trenches. Most of the time, positions remained unchanged, and in the rare cases where trenches were breached and "captured", armies would just move batteries to more "safer" locations.

But then again, there has, as of 1916, never been a particular breach to notice in any of the lines. World War I was extremely static.

However, artillery pieces have been captured during the war. Weighing hundreds of kilos (or even tons) each, it was very difficult to move these guns and find sufficient ammo to use them. If military logistics allowed it, batteries could be moved so they may be used against the enemy. Otherwise, batteries were destroyed, so as to make sure they wouldn't fall back to the enemy.