Peanuts are a tasty source of protein, vitamins A and E, zinc, iron, potassium and phosphorus, making them very nutritional for humans and birds. There are several factors and opinions involved in the choice of roasted or raw peanuts for both wild and pet bird food. Some birds are as picky as humans about what they will eat, but just like some humans, there are those birds that will eat just about anything.
The cooking process changes the physiology of the peanut, making it easily digestible for humans and animals. Bacteria and other contamination can be encountered during the shipment of raw peanuts and cooking generally kills anything picked up in transit. The FDA regulates all forms of marketed peanuts, including wild and pet bird food, and they are trying to stop the contamination during all phases of growth, sale and consumption.
Trypsin is a very important protease enzyme that breaks down protein complexes in the digestive system of most animals, including humans and birds. Without this enzyme proteins are not digested properly resulting in malnutrition, kidney and pancreas damage with long-term ingestion. Raw peanuts and other legumes have a substance that hinders or prevents the pancreas from producing trypsin. But roasted peanuts give birds an energy boost in winter and they will eat as many as are available.
Raw peanuts and other legumes are one of the primary sources of these toxins in animal and human food. Studies show birds to be more susceptible to aflatoxins than most other vertebrates, and pet birds especially will develop severe liver damage when given raw peanuts consistently over a long period of time. This group of toxins arises naturally in warm and humid growing conditions, is extremely potent and even tiny amounts can cause disease, including cancer, throughout the body.
Peanuts mold in hot, damp weather and they need checked often. Signs of black mold or darkening color indicate the peanuts are no longer edible. It is best to monitor the feeding habits and offer only as many peanuts as are eaten in a few days. Supplement peanuts with seeds that the local birds prefer to offer a well rounded diet. Remember to never feed salted nuts of any kind to pet or wild birds or other wild animals because long-term ingestion of salt will kill them.