in the 2019 thun calendar, they share the results of several trials they did comparing using the traditional methods of stuffing animal parts vs. using sheaths made from trees. after 2 yrs of trialing, they discovered that the highest yields and best results came from the vegetarian preparations every time. whether using horse or cow manure, the vegetarian tree sheath version outperformed the traditional animal version in every trial. seems using animal intestines are not only unnecessary, but in fact inferior. this is great news for me.. i've had great success using the thun calendar and making teas but would/will not use intestines since i'm a vegan and it goes against my ethics.. so yay! now i can add these preparations to my gardens also and it sounds like it will be all the better that i don't use animal parts.