Our diets contain organ meat such as pork liver, beef liver, beef heart, beef lungs and muscle tissue because organ meat is more nutrient dense than other types of meat. Organs are nature’s multivitamin. They are rich in protein and amino acids that help strengthen and maintain your pet’s muscles. They are particularly rich in B-vitamins, such as vitamin B12 and folate, along with choline. They are also rich in minerals, including iron, magnesium, selenium and zinc, as well as important fat-soluble vitamins like vitamins A, D, E and K