76 BULLETIN 1031, U. S. DEPARTMENT OF AGKICULTUEE. 



More complete information will be found on both lice and. ear 

 ticks in publications by the United States Bureau of Animal In- 

 dustry.^ 



EEDUCTION IN LOSS FROM POISONOUS PLANTS. 



There are a number of poisonous plants on the semidesert ranges 

 of southern New Mexico. Among these may be mentioned two sus- 

 pected species of Astragalus^ rattle- weed loco and blue woolly loco,^^ 

 which occur on and in the vicinity of the Jornada Range Reserve. 



Heavy losses among both cattle and horses on range adjacent to 

 the Jornada Range Reserve were attributed to the rattle-weed dur- 

 ing the winter and spring of both 1917 and 1918. The range was 

 so closely grazed that there was little other forage available, and 

 both classes of stock ate the rattle-weed freely. The same species 

 occurs to a considerable extent on the Jornada Reserve, but other 

 forage was always available, and no losses were experienced from it 

 under these conditions. This leads to the assumption that cattle do 

 not begin to eat the rattle-weed as long as there is sufficient other 

 forage on the range. 



The most effective means of avoiding losses from rattle- weed, 

 unless eradication is practicable, appear to be to avoid grazing the 

 range too closely and to feed susceptible stock. 



OTHEE CAUSES OF LOSS OF STOCK ON THE RANGE. 



Some other causes which contribute to the aggregate losses on 

 southern New Mexico ranges are predatory animals, accidents which 

 may or may not be avoided, and grazing horses and mules on the 

 same range with cattle. 



Coyotes cause occasional loss among young calves, but such losses 

 occur mainly when cows are too weak to protect their calves. An 

 occasional lobo wolf or mountain lion may cause some loss. The 

 work of the Biological Survey of the United States Department of 

 Agriculture in eradicating these animals has been a very important 

 factor in decreasing losses from this cause, and with continued activi- 

 ties of this bureau such losses should eventually become negligible. 



Weak cows are sometimes lost in spring from getting stuck in bog 

 holes. 'Such places should be fenced or watched to see that weak 

 cattle are kept away and that any cows that may have become bogged 

 down are pulled out. 



Horses and mules will often stampede around watering places and 

 run over and injure weak cattle and sometimes kill young calves. If 

 it can be avoided, this class of stock should not be allowed among 

 weak cows or those with young calves. 



26 Imes, Marion, " Cattle Lice and How to Eradicate Them," U. S. Dept. Agr., Farmers' 

 Bui. 909, February, 1918. Also, " The Spinose Ear Tick and Metliods of Treating In- 

 fested Animals," U. S. Dept. Agi-.,. Farmers' Bui. 980, May, 1918. 



"'Rattle-weed \oco= Astra(jalus aUochrous ; blue woolly '[■oco=AstragaJus bigelovil. 



