Vetch is a type of legume that is commonly used for forage and erosion control in horse pastures. There are several different types of vetch, each with its own unique characteristics and benefits for horses. Here is an overview of some of the most common types of vetch:

1. Hairy vetch: This is a hardy and drought-tolerant plant that is often used for erosion control and to fix nitrogen in the soil. It can provide a good source of protein and nutrients for horses, but it can also be toxic if consumed in large amounts or if it is moldy.
2. Common vetch: This is a fast-growing plant that is often used for forage and erosion control. It can provide a good source of protein and nutrients for horses, but it can also be toxic if consumed in large amounts.
3. Winter vetch: This is a hardy and drought-tolerant plant that is often used for forage and erosion control. It can provide a good source of protein and nutrients for horses, but it can also be toxic if consumed in large amounts.
4. Tufted vetch: This is a fast-growing plant that is often used for forage and erosion control. It can provide a good source of protein and nutrients for horses, but it can also be toxic if consumed in large amounts.
5. Nitrogen vetch: This is a hardy and drought-tolerant plant that is often used for erosion control and to fix nitrogen in the soil. It can provide a good source of protein and nutrients for horses, but it can also be toxic if consumed in large amounts.

If you are considering planting vetch in your horse pasture, it’s important to research the specific type you are considering and to seek expert advice on the proper management of vetch in horse pastures.