Beef kidneys for the Frankenprey diet
If you are familiar with the Frankenprey model, you know that secreting organs are required to fulfill 5% of the complete diet. Secreting organs include the spleen, pancreas, thymus, kidneys, and others. Believe it or not, some organs cannot be sold in grocery stores or butcher shops and must be specially purchased online. I have been fortunate enough to find local sources of three types of kidneys, so I don't feel the need to buy them through online vendors. Our local butcher shop strictly adheres to the "no preservatives, no hormones, no antibiotics" principle, and we appreciate it immensely. The three types of kidneys we purchase are those belonging to beef, calf, and lamb.
Beef kidneys for the Frankenprey diet
Beef kidneys for the Frankenprey diet
Lamb kidneys aren't as welcomed around here as calf kidneys, but the more variety, the better. They have a grassier odor versus the beef and calf kidneys and I don't think the little ones particularly like that smell. Calf kidneys have the least pungent smell and are the most liked. It may be different for you and yours. As a raw feeder, try and try again. If organs or meats from one prey animal are rejected, it doesn't mean all is lost. It's likely if chicken livers are walked away from, turkey livers may be gobbled up.
Calf kidneys for the Frankenprey diet
Kidneys secrete various hormones---used in red blood cell production, calcium absorption, iron and oxygen availability. They also excrete and remove waste byproducts, as creatinine, ammonium, and urea, from the body. While kidneys are full of all the B vitamins, they are jam-packed with B-12; 6 to 12X the daily requirement. A 28g slice has 245% of daily B-12. They also provide over half of the daily requirement of iron. Kidneys offer plenty of vitamin A, zinc, phosphorus, selenium, and copper.
Calf kidneys for the Frankenprey diet
Now, of course, secreting organs make up only 5% of the Frankenprey diet and this is because balance is needed. They are high in vitamin A, but so are prey livers. Because kidneys are organ meats, they are low in calcium and high in phosphorus in about a 1:20 ratio for a 1oz piece. Phosphorus and calcium cannot be in an imbalance.
Kidneys have to work hard to get rid of excess phosphorus and the excess phosphorus will bind calcium and hinder its absorption by the body. Calcium and phosphorus will cluster and lead to vessel blockage and organ calcification (kidneys are especially affected). The bound calcium is not recognized by the body as free calcium for use, so excess calcium is secreted from bones and storage and into the blood, causing weak and brittle bones. Feeding bones is an absolute must.
Lamb kidneys for the Frankenprey diet
Don't exclude secreting organs from a carnivore's diet. Kidneys are detoxifying organs and fulfill vitamin and mineral requirements that other organs and meats do not. Just make sure everything is proportionally balanced.
Other prey kidneys exist, but we have not tried anything else besides the ones mentioned---so I can't really write about that until we experiment with them. In general, other prey kidneys will have similar nutritional benefits as beef, calf, and lamb kidneys.
Nutritional Data:
Lamb kidneys for the Frankenprey diet
Your takeaway: Secreting organs fulfill 5% of the Frankenprey diet, so they should be fed on a regular basis. Kidneys are part of this category and the easiest to come by. They are detoxifying organs, full of B-12, provide half of daily iron requirements, and contain other minerals/vitamins. Kidneys, like other organs, are high in phosphorus and low in calcium, so it is important that the diet consists of 10% bones.
When to feed: We feed the Frankenprey diet over a week's worth of meals. For us, we feed kidneys once or twice a week.
How much to feed: The amount to feed depends on the animal's weight. A carnivore should eat 2-3% of body weight worth of food per day.
A 10lb hunter should eat 0.25lbs (4oz) of food per day to maintain weight. This equates to 2oz per meal if feeding twice daily. This is 28oz per week.
5% of 28oz is 1.4oz. So, a 10lb animal should eat 1.4oz of secreting organs per week. Either feed 1.4oz once a week or 0.7oz twice a week. Of course, if you feed twice a week, you'll add additional Frankenprey components so that each meal is 2oz.