You are eating the animal's sewer system. I used to like liver when I was toxic. I ate it frequently at Luby's. After doing six liver flushes, the entire Cure Zone cleansing protocol, rise and shine fasting, master cleanser, blood cleansing, liver cleansing herbs, etc etc etc, it now tastes like shit to me. But I would eat magic mushrooms again if I had some, and they grow on cow poop, so my opinion really isn't really worth much, since it could be viewed as very hypocritical. I would definitely be concerned about parasites, especially with the raw. There are other ways to get an energy boost, which won't last long if you pick up parasites. Iodine, for example, which cleans out the liver.

http://www.merckmanuals.com/vet/digestive_system/gastrointestinal_parasites_of_ruminants/gastrointestinal_parasites_of_cattle.html

Organ meats, cooked and raw, once were considered part of healthy eating .... but we are not in Kansas anymore.

On the road to ridding himself of terminal liver/pancreas cancer, Dr. William Donald Kelley made several references to the need for nutrition from animal parts in his book One Answer To Cancer, still available free online at a website maintained in his honor - http://www.drkelley.com/CANLIVER55.html

He mentions the benefits of consuming sweetbreads. The first time I read this I thought - cinnamon rolls, coffee cake, and the like, YAY, I never expected THAT to be a recommended part of eliminating cancer! Eventually I learned this is a slang expression for organ meats, especially Thymus, stomach and heart of calf. Here are some relevant excerpts.

- Missing Nutrients

The modern diet is quite deficient in certain foods that have in the past been mainstays of good nutrition and the support of health. The most outstanding missing group as a whole is the organ meats, such as kidney, liver, stomach, intestinal tract tripe, and lung. These health-building foods are unheard of and unavailable in today’s society. To get these today one must obtain them in the form of nutritional supplements.

Sweetbreads

Pancreas tissue or sweetbreads without a doubt, indicated by our 30 odd years of research, is the most deficient item in our food chain. It should be noted that the pancreas is the most needed of all the missing organ meats from our diets. It must be supplied in our diets or serious deficiencies result.

Low temperature processed pancreas gland enzymes are available to the public in various Metabolic Formulas listed below. These nutritional products are designed to support the normal metabolic processes of human metabolism.

- Liver

Liver is a wonderful energy food and cannot be surpassed as a blood builder. It is especially crucial for leukemia and lymphoma patients, as their blood is unusually weak. However, all cancer patients can benefit from the intake of raw liver before noon each day. In the mid 1960s, when Dr. Kelley was told he was in the final stages of pancreatic and liver cancer, he found that raw liver blended into carrot juice gave him strength when everything else he ate made him feel ill.

Raw organic, antibiotic-free and hormone-free liver contains a multitude of live enzymes, amino acids and other intrinsic factors that science has not yet identified, which are destroyed when the liver is cooked. (References to "intrinsic" or "unidentified" food factors are fairly common in nutritional literature. They result from clinical reactions, which cannot be linked to known nutrients. Raw liver for cancer patients is an excellent example of powerful therapeutic, but unexplained, effects.) There are no supplements or drugs that can take the place of raw liver; none are in any way comparable in their effects. Eating raw liver ensures thorough digestion and the replacement of expended nutrients, promoting excellent health.

Raw liver is best if it is organic, antibiotic-free, hormone-free and not irradiated. However, if this type of raw liver is unavailable, fresh muscle meat, steaks and ground, are acceptable even if you buy them at regular markets. Organically grown and not irradiated is always more nutritious and preferable. But if organic isn’t available, commercial is healthier than none. At least 3 and no more than 6 heaping tablespoons of raw liver should be taken daily.

Chewing the liver is best for proper digestion. However, if masticating it is too objectionable, it will digest well even swallowed whole, if it is sliced into small enough cubes, and if adequate hydrochloric acid and enzymes are taken.

There are two methods which people find suitable for preparing liver:

The liver can be sliced about ¼ inch thick, placed on a cookie sheet, and frozen. After it is frozen, it can be cut into ¼ inch cubes. One can then use plastic sandwich bags, putting 3 to 6 tablespoons of frozen cubed liver in each bag and storing them in the freezer for daily eating. This frozen liver may be chewed or swallowed whole, followed by a sip of juice if desired. Some prefer to allow the liver to thaw and then to place a spoonful at a time in the mouth and chew it or swallow it whole with a sip of juice.
Liver may be placed in the blender with carrot, pineapple, or tomato juice (and seasoning of one’s preference if desired), blended, strained to remove the fiber if preferred, and used as a morning "pep-up" drink.
Meat (Cooked and Commercially Produced)

The cancer patient will want to give up cooked and commercially produced meat such as beef, pork, lamb and fowl immediately (except for raw liver — see above). Cooked meat is harmful for the cancer patient, as the very same enzymes used in its digestion are needed for fighting and digesting the cancer. All natural, self-made enzymes your body can produce should be used to fight the cancer. Commercial meat should be avoided for another reason; it has a high female sex hormone content. For commercial reasons most animals, especially beef and fowl produced in the United States have been fed large quantities of hormones. Since an overabundance of female sex hormones initiate cancer, meat of this type should be excluded from the cancer patient’s diet.

- Type Two metabolizers must have meat — preferably fatty, heavy, high purine meats such as lamb, beef, salmon, and sardines. They are usually the people who order their steaks very rare. By eating these fatty meats, they slow down their carbohydrate/sugar metabolisms. They feel they have eaten something that will "stick to their ribs." Their energy is released at a normal rate and they don’t suffer the ups and downs energy-wise that fruits and sweets cause them to have. Normally, these metabolizers don’t care much for sweets. They do well on root vegetables, cabbage, Brussels sprouts, cauliflower, carrot juice, and beans. They enjoy butter, cream, Danish pastries, cream puffs and foods with cream or butter added. They can do well by adding a small amount of whole grains.