POISONING OF CATTLK BY DIPLODl A -INFECTED MAIZE. 447 



cobs fcrwarded for experiment contained only a small pcrcentat^e 

 of infected grains. 



Reference to these experiments will be found in a pamphlet 

 (Science BidleNii No. /), published in 1916 by Dr. van der Byl. of 

 the Division of Plant Pathology. This pamphlet gives a detailed 

 description of Diplodia zccc, with photographs of infected maize 

 cobs, and should be consulted by those interested in the following 

 feeding tests. 



From these previous experiments, it was concluded that the 

 maize so infected had no harmful effect on animals to which it 

 was fed. 



x'Mthough these results were fairly conclusive, the experience 

 of many farmers pointed definitely to the harmful results of 

 allowing cattle to graze in those mealie lands where cobs were 

 abundant, and for the first few days, at any rate, constituted 

 almost the sole article of diet. 



For this reason it was decided to commence a series of 

 experiments at the Maritzburg Laboratory, utilising mealie cobs 

 obtained from farms where the disease had recently occurred. 



Through the assistance of Mr. Power, Senior Veterinary 

 Surgeon, Natal, sufficient material was obtained for the tests 

 from, various farmers in the Estcourt Division. Some cobs were 

 forwarded to the Government Botanist, Pretoria, for determina- 

 tion of the infecting fungus present, and were rejxirted on by 

 him as follows: — "The mealie cobs referred to in your Minute 

 of 30th September last are infected with the fungus Diplodia 

 sccc." 



For the tests four oxen were selected which had been on 

 the station for about two years, and had been fed only en grass 

 in the paddocks adjoining the Laboratory. These animals were 

 about five years old, and in good condition. During the experi- 

 ments they were tied up in the stable, and watered by hand with 

 water obtained from the river close by. The mealies on the 

 cob were fed as received from the farmers, but in all cases only 

 the mealie grains were eaten, the central core being rejected. It 

 is therefore difficult to s^y definitely what weight of material was 

 actually eaten. 



Quantities of material fed : — - 



Ox 88 360 lbs. 



Ox 90 - 270 lbs. 



Ox 94 225 lbs. 



Ox 87 ad lib., about 145 lbs. 



Of these four animals one ox did net show any symptoms, 

 and the remaining three developed typical symptoms. 



General Notes on the Experiment. 



With the exception of Ox No. 87, the feeding on the mealie 

 cobs was discontinued as soon as the first symptoms were shown. 



E 



