(Also read "Plants That Goats Won't Eat" for tips on landscaping and gardening)

As I began compiling this research data, it suddenly dawned on me that Nutrition and Food Source is just that - nutrition and food source. Any food that can be considered good and nutritive, when consumed in excess can just as easily be bad. Applying the economic "law of marginal utility" to this topic is probably the best rule of thumb a person could follow.

Feeding your goat the same thing, in excess, day in and day out for long periods of time may be just as harmful (and fatal) as feeding the goat a known toxic plant. From my research, goats are finnicky eaters and probably instinctively know what to eat, how much to eat, and when not to eat it. Goats are browsers. They are not grazers and do prefer variety. We as the goat owners are an influencing factor in the equation. Deprive and starve your goat from getting a balanced diet and you are forcing that goat to eat whatever it can just for the sake of not going hungry. Please think about this when you are determining your goat's food source.

To date I have learned that there are ten (10) very important classes of poisonous plants:

Alkaloid Containing Plants: ^Alk "Any of a large class of organic, nitrogen-containing ring compounds that have a bitter taste, that are usually water-insoluble and alcohol-soluble, that form water-soluble salts, and usually exhibit pharmacological action, as nicotine, morphine, or quinine."

Cyanogenetic Containing Plants: ^Cya "These plants are usually deadly when damaged or frozen."

Glucosides - Glycosides Containing Plants: ^Gls "Any of the class of compounds that yield a sugar and a noncarbohydrate upon hydrolisis."

Plants That Cause Mechanical Injury: ^Int "It should be obvious that some plants and shrubs have physical characteristics that would be injurious to animals - thorned plants as an example. Certainly some thorned and spiked plants may be eaten but once they reach the palate, punctures and tears can occur internally which cause a great degree of injury. Also, certain plants are known to 'twine' or 'bind' causing great intestinal difficulties."

Saponin Containing Plants: "Any of a group of amorphous glucosidal compounds of steroid structure, characterized by an ability to form emulsions and to foam in aqueous solutions, and used as detergents."

Volatile/Essential Oils Containing Plants: "Some plants, trees and shrubs contain volatile chemicals that go beyond 'general classification' and are thus unique. This simply means that there may be one or more ingredients within the chemical structure of a plant that causes adverse reactions in the animals who ingest it."

Photosensitizing Plants: ^Pht "This type of plant will cause a reaction whereas the ingredients interact with light. An animal ingesting such a plant is susceptible to sunburn, heat related illnesses, etc. Not all photosensitizing are considered extremely harmful, however, dependent upon climatic conditions/light, this class of plants can do great damage if the animal is not monitored."

Tannic Acid Containing Plants: "I am currently researching Tannic Acid. I am somewhat intrigued by this particular ingredient since many Oak trees contain Tannic Acid and this basically provides much conjecture with the belief that fresh, green oak leaves are soothing to sick goats. I will write more on this subject at a later date."

Resin Containing Plants: "This area is also under research since it has been a common practice for many goat owners to feed their discarded Christmas trees to their goats. Apparently this is not such a good idea as while it may not produce immediate, noticeable results, it can be a cause of abortions months later."

Poisonous Principle Not Yet Known: "Despite sending a man to the moon, space probes to jupiter and the cloning of sheep, there are still mysteries left in the world to unravel. So be it with the plant kingdom and plants whose toxic properties cannot be identified. There are a few and in reality, probably more than we really know about. I will attempt to research as many of these as is humanly possible."

In closing I'd just like to say that in my opinion, and for all scientific research only, there certainly has to be a relation between the physiological makeup of a goat, the chemical balance, and the goat's ability to eat certain known poisonous plants and not be adversely affected. I've read many posts where this is truly the case. Yet, in other circumstances, people will write and say that 'just a little' of a certain plant brought an immediate, deadly reaction. Is it a balance between chemicals from plant to plant or is it simply that 'some' goats have the tolerance built into their DNA while others do not. It certainly is a mystery that I would like to unravel.

We welcome your thoughts and input on any of the plants listed (or not listed) here. With your help perhaps we can further discover more about what to feed and what not to feed our goats. If you have any pictures or information regarding any of the plants, please let us know. We are only happy to share this information with you and others around the world.
-- by Gary Pfalzbot, GoatWorld.com