THE OCCURRENCE AND POSSIBLE TOXICITY OF 

 MOLDS IN CORN SILAGE. 



ALVIN R. LAMB. 



Frequent cases of suspected forage poisoning in this state 

 which apparently were traced to moldy silage, led to this study. 

 The silage in a silo below the surface layer is almost always free 

 from mold, at least when properly packed and containing a suf- 

 ficient amount of moisture. Occasionally, however, clumps of 

 mold are found far below the surface and in the interior of the 

 mass where the amount of oxygen is almost negligible. In order 

 to secure a considerable number of samples of such moldy silage, 

 notices were sent out to the newspapers of the state through the 

 press bulletin, "Better Iowa." 



A number of samples of the kind of material wanted were re- 

 ceived. In all cases, as in the case of samples previously sent in 

 for examination, the molds present were of the same character- 

 istic red or green color. In the samples studied the red mold was 

 in each case isolated and identified^ as Monascus purpureus 

 Went, which was found in silage some years ago by Buchanan.- 

 This mold forms in silage thick cottony masses of white myce- 

 lium, often tinged with carmine red. In cultures well advanced 

 in age the whole mass takes on this characteristic color. The red 

 pigment is easily soluble in water and diffuses through the sur- 

 rounding silage, coloring the kernels of corn a homogeneous pink 

 or carmine. The fact that this pigment penetrates beyond the 

 moldy region is sometimes a source of confusion in the examina- 

 tion of such silage. 



This mold was grown successfully on various modifications of 

 Raulin's medium. The addition of silage juice to the medium 

 did not generally increase either the color or the luxuriance of 

 the growth. The growi;h was most luxuriant, of course, with su- 

 gar in the medium, but the production of the red pigment was 

 more marked in the absence of sugar. Both on agar and liquid 

 media the pigment was produced below the surface of the me- 

 dium. 



The greatest production of the pigment was obtained in cul- 

 tures grown on rice flour paste after the method of Buchanan. 



^The identity of these two species was very liindly confirmed by Dr. 

 Charles Thorn of the Bureau of Chemistry, W^ashington, D. C. 

 «Mycologia, Vol. 2, pp. 99-108, 1910. 



