458 TiiiRTY-FiRST Annual Ricport 



feed, a change of pasture, or turned out on the open range where 

 feed was fairly good. 



The first indication of this disease in animals is lack of thrift". 

 They become gaunt, listless, separate from the herd, and lie down. 

 The horses appear fagged as if overridden and exhausted. The 

 disease seemed to exist in two forms. In the acute form the ani- 

 mals have some fever and die within a day or so, while in the 

 slower form they linger three to five days, losing flesh and becom- 

 ing weaker. A few hours before dying they tremble violently, 

 often fall down with the legs spread out, drop the head and neck, 

 and froth at the mouth. Some animals break down over the loins 

 and fall down with their hind legs sprawled out. The disease 

 attacks both sexes and all sizes, ages, and conditions of animals, 

 and very few of the affected ones recover. 



The rayless goldenrod or burro weed (Bigcloivia coronopifolia) is 

 abundant over large areas on the desert ranges and valley lands in 

 southern x^rizona. It is less abundant on the prairies. It belongs 

 to the goldenrod group of the sunflower family and is a woody 

 shrub one to three feet tall. The leaves are skeleton-like, and 

 pinnately parted nearly to the mid-ribs. The flowers are golden 

 yellow, and borne mostly in terminal clusters in the summer and 

 fall. The whole plant is strongly resinous, with a pronounced 

 bitter odor, and stock rarely eat it except when driven by stress of 

 hunger. Sheep and goats, however, eat the blossoms and seed 

 heads and appear to relish them. 



A shrub nearly related to this goldenrod grows throughout the 

 Gila Valley in Arizona and is known to stockmen as "jimmy weed.'' 

 This plant is Bigcloivia hcterophyJla and is believed to be the cause 

 of the disease among stock known as "jimmies," losses from which, 

 though rarely heavy, occur each year. Bigeloivia IVrightii is still 

 another plant belonging to this group of rayless goldenrods. This 

 species grows in New Mexico and is known to cause losses among 

 stock during the fall and winter months. 



FEEDING EXPERIMENT WITH RAYLESS GOLDENROD 



To determine whether rayless goldenrod was the cause of the 

 losses of stock noted above, a quantity of the material, including 

 the woody stems, leaves, and herbaceous growth, was gathered, 

 dried carefully, and ground into a meal. This was fed to a mare 

 kept in a stall so that she could get no feed other than what was 

 given her. She was allowed all the water she would drink. To 

 maintain her on a barely living ration, she was fed daily one pound 



