Feeding
A cow can eat up to 30 pounds of grass in a day and a wolf can gobble down 20 pounds of meat in a single meal. But more important to Ars Magica Fifth Edition stories are the type and availability of a beast's food, rather than how much of it is necessary for survival. Magical animals do not need to eat, although most enjoy it. Magical creatures that are starved will not die, but will desperately desire to escape, be more prone to violence, and will refuse to reproduce. Providing adequate food and water can be one of the many challenges that hinder developing a menagerie.
Feeding captured animals is the most labor intensive part of the operation. There are no holidays from feeding livestock, and a magus who personally manages his menagerie needs to spend part of each day feeding his creatures. A kind storyguide will allow such a magus a regular laboratory season, counting the ten days that any magus can miss without decreasing Lab Totals as the time spent tending the animals. Any other sort of mishap or distraction will count as missed time and affect a Lab Total. A less kind storyguide might impose an automatic penalty to Lab Totals, depending on the number of creatures the magus needs to feed, balancing the character's score in Animal Handling against the number of animals.
Oats, grains, and raw meat can usually be acquired easily, although a story

could be derived from a lack of adequate food stocks. Magical animals should have other dietary staples as well; a griffin eats gold, a Siberian six-legged antelope eats bark from a sacred birch tree, and a roc eats an entire elephant once a month. Finding exotic foodstuffs is an adventure in itself, and maintaining the supply will be a challenge. Adequately feeding a roc might mean maintaining and breeding a herd of elephants.
A magical alternative is to create foodstuffs using appropriate Creo spells. Nutritious food can only be created using rituals spells. Formulaic spells will create the food, which the animal will eat, but will not provide the same satisfaction as permanent food. Non-permanent food is better than no food, but will still leave the animal agitated and temperamental.