Alpaca breeders use a number of grasses when planting their pasture. It is important for all grasses to be endophyte free. When ordering grass seed from your farm extension have this discussion with your ordering source just to be on the safe side.
Ideally an equal mix of 4-6 different grasses when planting is ideal as alpacas love to forage and have a variety in their diet. The happier your alpacas are with their pasture, the more they will forage; foraging is beneficial to insure that your alpacas are getting a healthy and varied diet of nutrients and having a variety of grasses makes it palatable for them.
(Alpaca Owners Association)
As you begin developing your ranch you may have pastures in place from the previous owner or owners. Or you may have lush rich dark soil and sufficient annual rainfall to maintain the pastures. Others live in areas where some grasses do well and other do not or growing pasture is out of the question because of the climate.
Typically alpacas can graze on pasture that other livestock has gazed upon, however, there are some important considerations prior to bringing your alpacas home to a new pasture. The pasture should be cleaned and cleared of debris, also consult with your veterinarian or your veterinary manual (for any medical considerations) or your county extension for ideal grasses for your climate.
If the pasture is over grazed or has been overtaken by weeds it may be a really good time to replant the pasture areas. Using a herbicide to eliminate current growth may be the best option before seeding the pasture. Alpacas, in general, like 60% of their forage to come from grazing, so a great pasture is ideal for them. Then it is time to plant, allow the pasture to begin filling in and then you may wish to put down fertilizer and weed control. Each time you fertilize, the pasture must be closed off to your alpacas for three weeks.
The Alpaca Hacienda