Yes
Magnolias are a group of trees and shrubs some of which bear large flowers.
Deciduous magnolia trees, such as the Southern magnolia (Magnolia grandiflora) and the Saucer magnolia (Magnolia × soulangeana), lose their leaves in the winter. Evergreen varieties, like the Sweetbay magnolia (Magnolia virginiana), retain their leaves throughout the year.
Yes, cows eat grass and leaves; but do not eat meat and fish.
Goats can and quite often do eat grass just like cows do. Cows will eat leaves as well: grass is pretty much all leaf anyway, but cows will eat leaves off of forbs, trees and shrubs as much as possible or as high as they reach. However, goats are not roughage grazers, rather they are what are called "selective grazers" like deer are, meaning they like or choose to eat leaves from forbs and shrubs than grass.
Yes, they can. Are they poisonous? Consensus view says no.
Yes, cows can safely consume beetroot leaves as well as the beetroot itself. The cow may not have a liking of them however.
Yes. Grasses are essentially leaves, cows will also eat leaves off of trees and shrubs and eat leaves (as well as the stems) from forbs like alfalfa.
Yes, they all do.
No
Yes, magnolia seeds are toxic if ingested in large quantities as they contain alkaloids that can cause gastrointestinal upset, diarrhea, and vomiting. It is not recommended to eat magnolia seeds.
Magnolia
See this link.