Gárnoth's Farm was known for the quality of cattle and meat once produced there, but these days there are not many domesticated cows left in the Fallows. Most of those cows are still on the farm, and should not be left to become food for the Orcs.
Gárnoth's Farm has a few cows left behind from when the farm was abandoned. Their masters frequently took them to Forlaw's market and would know the paths to get there. If the cows are freed, they should make their way to the city, or may end up wandering the plains, but that would be better than leaving them to an unpleasant fate.
The cows left behind at Gárnoth's Farm are grazing in pens throughout the farm.
The Orcs occupying Gárnoth's Farm have managed to keep many cows corralled. They seem to be using them as a local food source instead of relying on shipments from elsewhere.
The Orcs can no longer rely on the local food source, and will once again have to rely on shipments from elsewhere.