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Bull Testicles: Nutrition and Benefits of “Rocky Mountain Oysters”

By Liam McAuliffe Published on

Bull, lamb, goat, buffalo, and boar testicles are enjoyed as food all around the world. In America, bull testicles are the most common, and go by many names like cowboy caviar, lamb fries, bull fries, Montana tendergroin, and of course, rocky mountain oysters. 

Loaded with protein, vitamin B, selenium, and zinc, there’s no reason not to go nuts with these, well, animal nuts. 

In this article, we’ll explore the origins, nutrition, benefits, taste, texture, and easy rocky mountain oyster recipes. Let’s have a ball!   

Table of Contents

What are Rocky Mountain Oysters?

Rocky mountain oysters are bull testicles. They became associated with the rocky mountains and the American West when the first ranchers needed healthy, inexpensive food. 

In the good old days, food wasn’t convenient, and people practiced nose-to-tail eating. They knew the nutritional value of the whole animal, and nothing was left to waste. 

Out on the prairie, it was inconvenient to kill and butcher a cow. But young male cows were routinely castrated in order to reduce aggression and fighting, improve meat quality, and control breeding. 

Cowboys learned to love these nutrient-dense organ meats that they could harvest on the move without decimating their herd.  Cowboys seared up fresh bull testicles with branding coals for an on-the-job treat. 

Meat cooking on top of steaming metal grilling device while men lean against metal fence in the background in Flint Hills, Kansas, USA

Often larger castration events would turn into big nut-eating parties, the legacy of which persists to this day in annual “Testical Festivals” across the Western U.S. and Canada. 

You can watch the Liver King “enjoy” a raw testicle below.

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Rocky Mountain Oyster (Bull Testicle) Nutrition

Animal testicles are more than just a gimickey treat–they’re loaded in nutrients, and they don’t taste half bad. 

For such a popular food, it’s nuts that the nutritional profile for bull testicles is incomplete. To help fill out the picture we’ll include both bull and New Zealand lamb testes nutrition info. 

Nutrient Amount per 100 grams of Rockey Mountain Oysters
Fat3 grams
Protein 26 grams
Cholesterol 375 mg
Carbohydrates 1 gram
Potassium 380 mg
Iron6% RDV
Phosphorous 26%

Though amounts remain unspecified, researchers from Colorado State University classify Rocky Mountain Oysters as either an “Excellent Source” or “Good Source”, per the USDA guidelines, of vitamins and minerals including Vitamin K2, Vitamin D, B-12, Vitamin A, and Vitamin E. (3)1 

Both bull and lamb testicles are extremely nutrient-dense foods.

Lamb Testes Nutrition

lamb testicle nutrition stats

list of vitamins in lamb testicleslist of minerals in lamb testicles

Benefits of Eating Rocky Mountain Oysters (Beef Testicle) 

Large testicles of a bull of Portuguese breed, northern Portugal

When it comes to eating organ meats, traditional peoples often take a like-supports-like perspective. This is a belief that eating an organ will have specific benefits for the corresponding organ in your own body. 

Modern science suggests that there is biological truth to this claim. For example, beef heart has the highest concentrations of the heart-healthy compound CoQ10, which has been shown to help heal and reduce the risk of heart disease.4 5

Rocky mountain oysters and the testes of other animals have been prized around the world for their purported libido-boosting benefits. 

Though popularly attributed to consuming the animal’s testosterone, research shows that unless eaten raw, animal testicles have only trace amounts of testosterone. 

But there are numerous vitamins and minerals in testes that support fertility and virility. 

Rocky Mountain Oysters Support Reproductive Health

Rocky Mountain Oysters are great sources of key minerals needed for healthy fertility and testicular function including zinc, selenium, iron, and B vitamins. (3)


Selenium has been shown to increase sperm motility, and the combination of selenium and vitamin E can decrease damage from free-radicals while improving sperm motility in infertile men.4

Other ​​research suggests that selenium deficiency can factor in miscarriage and semen quality. 

Selenium also supports the quality of follicular fluid around women’s eggs. (28 31


Zinc is a trace mineral that plays an essential role in sperm formation, and testosterone metabolism. Zinc can increase testosterone levels, sperm count, and sperm motility, especially when combined with selenium.3 5


Having higher blood levels of vitamin B12  has been found to enhance fertility in women undergoing infertility treatment. 24

Other research suggests that  B12 can improve sperm quality. 25

Vitamin E

Vitamin E provides antioxidant properties that may promote sperm function in men. This nutrient also supports general reproductive health in women.  (33, 34

Taste of Rocky Mountain Oysters

It may be cliche, but a fresh rocky mountain oyster fried in batter tastes a lot like chicken crossed with very thin pork tenderloin. 

Texture of Rocky Mountain Oysters

The texture is very tender, easy to bite into, and without toughness. Expect it to be juicy and succulent, almost like really moist dark meat chicken.

Believe it or not, the texture of a rocky mountain oyster is a good reason to give them a try. 

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Keto Rocky Mountain Oysters Recipe

carnivore diet rocky mountain oysters

Rocky mountain oysters are rather lean on their own. This variation on the traditional fried rocky mountain oyster recipe will help you boost the fat content and meet your keto macro percentages


  • 2lbs rocky mountain oysters
  • 1 cup coconut flour 
  • 1/2 cup Parmesan cheese finely grated
  • 2 egg large
  • ⅓ lb tallow or lard for frying
  • Salt to taste


  1. Place rocky mountain oysters on a paper towel to dry
  2. In a medium-sized bowl, mix together coconut flour and Parmesan cheese.
  3. In a separate, medium-sized bowl, beat the eggs.
  4. One at a time, lightly coat the “oysters” in the coconut-Parmesan mixture. Transfer the oyster to the beaten egg, then right back to the flour-cheese mixture. Set aside until all “oysters” have been coated.
  5. Heat your tallow or lard in a large frying pot over medium-high heat. Once bubbles appear, gently place your breaded “oysters” into the pot.
  6. Fry each side of the “oyster” until the breading becomes a golden color. Note: make sure to turn the “oysters” so the cheese in the breading doesn’t stick to the bottom of your pan.
  7. Transfer the “oysters” to a dry paper towel. 

Enjoy on their own or with keto condiments like keto mayo, ranch, cheese sauce, or BBQ sauce. 

Carnivore Diet Rocky Mountain Oysters Recipe

Spanish tapas of criadillas de toro battered with wheat flour, breadcrumbs and egg on wooden table

Here’s another variation on the beloved fried rocky mountain oyster, just a heck of a lot healthier and tastier, and completely made with animal products for a carnivore diet snack. 

In place of unhealthy seed (vegetable) oils and grain flowers, we use wholesome pork cracklings (or rinds), and molecularly stable animal fats for frying. 




  1. Blend the pork cracklings* and until they reach the consistency of an oily powder
  2. Place the pork crackling powder in a medium-sized bowl 
  3. Beat two eggs in a small bowl.
  4. Dip each bull testicle into the egg mixture. Once fully coated, immerse it into the pork crackling powder and roll it around until it’s fully coated with a thick layer. The powder will be oily and should stick together. Make sure the breading layer is thick.
  5. Place the coated rocky mountain oysters on a parchment paper-lined baking sheet. 
  6. Salt breaded testicles liberally
  7. Bake for 20 minutes at 400 degrees, flip, then bake for another 20-25 minutes
  8. Dip in melted carnivore diet blue cheese and enjoy!

When finished, the coating should be hard to the touch and crunchy. 

If you make them in an air fryer, cook for 20-30 min at 400 degrees. 

Rocky Mountain Oysters: The Bottom Line

More than a novelty, rocky mountain oysters are nutrient-dense organ meat with a surprisingly tender texture and mild flavor. 

The combination of complete proteins along with robust amounts of essential nutrients like B vitamins, selenium, and zinc make rocky mountain oysters a potent snack that will support the health of your own sack. 


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