I wanted to start off with “What is offal?”, but if you understand what is meat, you will find it easier to understand what offal is.
First off, it is helpful to know that there are 3 types of muscle fibre.
- Skeletal, which we normally think of as ‘meat’ and which themselves come in different types depending on their activities and the demands put upon them by the body. Type 1 are found around the neck and spine areas and type 2 are found in the limbs. They have different levels of blood and enzymes in them so it is probably better to have a mix of meats from different parts of different animals to prevent an overload or deficiency of specific nutrients. Chicken, pork and beef is around 17-23% protein, 3-19% fat and 55-70% water depending on how much fat has been trimmed off (lean meats contain more water). Trimmed beef and pork have similar fat levels to skinless chicken.
- Smooth or intestinal, which we often give to our dogs as tripe (it is a part of the stomach). This muscle type is also found in blood vessels and other ducts and tubes. Tripe is around 12% protein, 4% fat and 85% water and lungs are 16% and 3% respectively and both are high in cholesterol. Offal, while it is fed in limited quantities (usually 10%), it has similar protein and fat levels to smooth muscle.
- Cardiac, which is obviously found in the heart and is very similar to skeletal muscle. Ox heart is 18% protein and 4% fat and is also high in cholesterol. Cardiac muscle is also rich in blood which is also high in protein and low in fat.
As is becoming clear, protein is found in meat but not all protein is meat.