These are horses grazing out in the desert.  Driving down the roads here on the Navajo Reservation you see alot of cows and horses.  Every once and awhile you see sheep.  The cows and horses appear to be fending for themselves and graze on the sparse vegetation.  They appear to get enough food and all look very healthy.  Many times the horses and cows have gone through the fences and they graze along the road and the cars just drive around them.