This is an interesting website https://www.ansci.cornell.edu/plants/medicinal/index.html My own experience is limited but i have seen Russian comfrey used as a stock food for NZ Racehorses and Dairy Cows. Rarely do Australian farmers have enough water for it (now might be an exception?) https://www.ansci.cornell.edu/plants/medicinal/comf.html A friend helped a cow with 'stuck' afterbirth with wild raspberry leaves (in molasses). it seemed to work extremely well. Another friend, very organic, who fed her chooks on heaps of Comfrey leaves was visited, by the Government heavies that concern themselves with such things, and told not to use so much "yellow dye" as her bright yellow egg yokes were obviously chemically induced! Many herbalist get into herbalism by not being able to afford vet bills! Bairacli Levy's books seem to be an exceptionally good resource Bairacli Levy, Juliette de. 1991. The Complete Herbal Handbook for Farm and Stable, 4th ed. Faber and Faber, NY. Anyone got any first hand experiences of remedies that work?