Timothy Hay is easier to get and provides the optimal balance of nutritions ranging from fiber, protein, and calcium for guinea pigs. The high fiber content found in timothy hay helps maintain normal digestive health.
Orchard hay is an excellent alternative for guinea parents who have allergy to timothy hay. Orchard hay tends to be softer, sweeter, and also has an aromatic fragrance which will entice even the pickiest of eaters. The nutritional value of orchard hay doesn't fall much behind of timothy hay, boasting high fiber content, and having a slightly lower protein content.
If you'd like to learn more about different types of hay for guinea pigs you can read more about it here!