17 



The feedings of hay and milkweed may be briefly summed up for 

 range ewes as follows: (1) 3 ounces may or may not make the animal 

 sick, (2) 4 to 6 ounces will usually produce poisoning, (3) amounts in 

 excess of 6 ounces will probably cause death. 



The dried milkweed is evidently very poisonous. While the plant is 

 green sheep are very likely to avoid it because the taste is repellent ; 

 but after it is dry it loses much of its bad flavor and is then more 

 dangerous because more readily eaten. 



It takes about three parts of fresh milkweed to make one part of 

 air-dried; and it is an interesting fact that if the above amounts of 

 air-dried material are multiplied by 3 to give the original green 

 weight they agree very closely in most cases with the results of Table I. 



The feeding tests given in Table II therefore indicate that drying 

 causes little if any loss of the poisonous principle. Consequently when 

 this milkweed is cut and fed in hay, it becomes a serious source of 

 danger. 



TABLE III 



The Narrow-Leaved Milkweed The Plant Which Had Dried Naturally in the 



Field Fed to Sheep 



The plants which were used in the above feeding tests were collected 

 in late autumn after they had fully matured and become dry. The 

 feedings were made in the months of November, December, and Janu- 

 ary. The results may be summed up briefly as follows: (1) small 

 amounts up to 3 ounces are not dangerous, (2) amounts from 5 to 16 

 ounces will usually produce poisoning, (3) amounts in excess of 16 

 ounces are extremely dangerous, and are likely to cause death. 



Comparing the results given in Table I with those of Table III, it 

 is found that it takes about as much of the naturally cured material, 

 dry weight, to cause death as of the fresh green plant. From this it 

 appears that some of the poison is destroyed or lost when the dried 

 plant stands exposed to snow and rain after the leaves are dead. 



During the fall and winter months the dried plants may be found 

 still standing. Other feed is usually very short and scarce at that time 

 of the year; and the narrow-leaved milkweed, still retaining a con- 

 siderable part of its original poison, is then a source of danger to 

 grazing animals. 



TABLE IV 

 The Narrow-Leaved Milkweed Seeds Fed to Sheep 



