Tapioca comes from a plant called Manihot Esculenta that is grown in the tropics. The fleshy roots (tubers) are processed and dried in the sun to destroy the cyanide present, with the resultant product being tapioca.
Tapioca is a high quality energy supplement, with similar starch content to maize grain, but is low in protein and not as palatable. Therefore, tapioca is a good feed for early lactation when there are high protein levels in pasture.
The risk of acidosis is high due to the high starch content and the finely ground nature of the feed before being pelletised. If cows are allowed ad libitum access there is a significant risk of rumen acidosis and death. Therefore feeding ad libitum in bins is risky and should only be fed as a blend with PKE at no more than 25 % tapioca: 75% PKE.
If fed in the shed where intake is controlled you can feed up to 2.5 kg/c/milking in the spring and 2.0 kg/c/milking in mid to late lactation as long as the normal protocol of gradual introduction is followed (begin with 0.5 kg/day of Tapioca and increase by 0.5 kg/day to desired amount).