If Owen has an Appaloosa mare weighing 1,000 pounds and standing 14.3 hands tall, how much long-stem roughage should he feed her daily?

The correct answer is based on an understanding of the nutritional requirements of horses, particularly regarding long-stem roughage, which is essential for their digestive health. Horses should ideally consume at least 1% of their body weight in long-stem roughage each day to support their digestive system and prevent issues such as colic.

Owen's mare weighs 1,000 pounds, so calculating 1% of her body weight yields 10 pounds of roughage. Feeding her at least this amount helps ensure she gets the necessary fiber for good digestion and overall health.

While options indicating amounts greater than 10 pounds could also support her needs, the minimum requirement for her weight is adequately met by the 10 pounds specified in the correct answer. This is why this choice is the appropriate response for her dietary needs.