What Percentage of Bone Meal is Protein?

The amount of protein in bone meal can vary from less than 1% to over 50%, a significant range determined by the manufacturing process. A common misconception is that all bone meal is a substantial protein source, but this depends entirely on whether it contains other animal materials and the degree of heat processing it undergoes. Knowing what percentage of bone meal is protein requires understanding the specific type of product being used.

Quick Summary

The protein content of bone meal is highly dependent on its processing method. Traditional steamed bone meal has some protein, but calcinated bone meal has virtually none. In contrast, meat and bone meal is a rich protein source. Variations arise from different raw material compositions and heat treatment, affecting overall nutritional value.

Key Points

• Processing Determines Protein Content: The percentage of protein in bone meal is not fixed and depends on its manufacturing process. Calcinated bone meal has no protein, while steamed and meat and bone meal contain varying amounts.

• Calcinated Bone Meal is Protein-Free: This high-heat process removes all organic content, resulting in a mineral-only product containing 0% protein.

• Steamed Bone Meal has Modest Protein Levels: Processing with steam retains some organic matter, providing a small percentage of crude protein, typically between 6% and 10%.

• Meat and Bone Meal (MBM) is a High-Protein Source: By including meat tissues, MBM can contain 45% to over 50% protein, making it primarily an animal feed ingredient.

• Check N-P-K Ratios for Guidance: For gardeners, the NPK ratio can indicate protein content; a non-zero 'N' value suggests the presence of nitrogen derived from protein.

Protein Percentage Varies with Bone Meal Type

Unlike meat, which is primarily protein, bone is composed largely of inorganic minerals like calcium and phosphorus. The final protein percentage of a bone meal product depends heavily on how it is processed and whether other animal tissues are included. Simply stating a single percentage for all bone meal is inaccurate.

Calcinated Bone Meal: The Mineral-Focused Option

Calcinated bone meal is produced by heating bones to very high temperatures, effectively burning off all organic matter, including protein. This process leaves behind a product that is almost entirely ash, consisting of calcium and phosphorus. Consequently, calcinated bone meal contains virtually no protein. It is primarily used as a mineral supplement or fertilizer where the focus is solely on boosting calcium and phosphorus levels in the soil or in animal diets.

Steamed Bone Meal: Some Residual Protein

Steamed bone meal involves processing bones with steam and heat, but at a lower temperature than calcination. This method is designed to remove fat and sterilize the bones while retaining some of the organic material, including the protein and nitrogen content. According to Feedipedia, steamed bone meal contains an average of about 8% crude protein, though this can range from 6% to 10%. This product is still primarily valued for its slow-release phosphorus and calcium, but the small amount of protein contributes to its overall nutritional profile.

Meat and Bone Meal (MBM): A Protein Powerhouse

Meat and bone meal (MBM) is fundamentally different from traditional bone meal because it incorporates more than just bones. MBM is made from rendered animal by-products, including meat trimmings, offal, and bones. This inclusion of muscle tissue significantly increases the protein content. High-quality MBM typically contains a minimum of 50% crude protein, and some variations can contain even more. As a result, MBM is a valuable and cost-effective source of protein for animal feed, though its use is restricted in some areas due to regulations concerning BSE (Bovine Spongiform Encephalopathy).

The Impact of Manufacturing and Sourcing

The variability in bone meal's protein content highlights the importance of understanding its origin and processing. Manufacturers and suppliers must provide clear labels detailing the crude protein, calcium, and phosphorus content. For organic gardeners, pure steamed bone meal offers a balanced approach, providing essential minerals and a small amount of nitrogen from the protein. For animal feed manufacturers, the higher protein concentration of MBM is a key factor in formulating feed rations.

Comparison Table: Protein in Different Bone Meal Types

Feature	Calcinated Bone Meal	Steamed Bone Meal	Meat and Bone Meal (MBM)
Protein Percentage	~0%	6%–10%	45%–55% or higher
Key Nutrient	Phosphorus and Calcium	Phosphorus and Calcium	Protein
Processing	High-heat calcination; burns off organics.	Sterilized with steam; retains some organic matter.	Rendering of meat and bone tissue.
Primary Use	Mineral supplement, soil pH correction.	Slow-release fertilizer for root growth.	High-protein animal feed ingredient.
Organic Matter	Virtually none.	Low to moderate levels.	High levels due to meat content.

Conclusion

The question of what percentage of bone meal is protein has no single answer because the composition is not universal. The protein content is entirely dependent on the type of bone meal you are examining. For gardeners seeking a mineral supplement, calcinated bone meal is the best choice, but it contains no protein. Steamed bone meal offers a modest protein boost along with minerals, making it a good all-around organic fertilizer. For animal nutrition, meat and bone meal is the appropriate choice, offering a substantial protein source alongside its mineral content. Always check the product label for specific nutrient percentages and processing methods to ensure you are getting the right product for your needs.

Key Takeaways

• Protein in Bone Meal is Highly Variable: The protein content is not standard and depends entirely on the manufacturing process and inclusion of other animal tissues.
• Calcinated Bone Meal has No Protein: This version is heated to extremely high temperatures, removing all organic content, resulting in a mineral-only product.
• Steamed Bone Meal Contains Some Protein: A less intense heating process leaves some organic material intact, giving this type of bone meal a small protein percentage (around 6-10%).
• Meat and Bone Meal is a Rich Protein Source: The addition of rendered meat and offal makes MBM a high-protein ingredient, often over 50%, primarily used in animal feed.
• Read the Label: To determine the exact protein content, always check the product's nutritional or N-P-K (nitrogen-phosphorus-potassium) ratio, as nitrogen is directly related to protein content.
• Product Sourcing Matters: Be aware of the distinction between pure bone meal and meat and bone meal, especially regarding use in animal feed and compliance with regulations.

FAQs

Question: Can I use bone meal as a protein supplement for my pets? Answer: No. While some animal feed uses meat and bone meal, pure bone meal is not a protein source, and the safety and proper dosage of animal feed-grade supplements should be handled by a professional nutritionist.

Question: Does bone meal provide nitrogen for plants? Answer: Yes, steamed bone meal contains a small amount of nitrogen due to its protein content, but it is primarily a source of phosphorus and calcium.

Question: How can I tell the difference between steamed and calcinated bone meal? Answer: Steamed bone meal will typically have an NPK ratio with a small nitrogen number (e.g., 3-15-0), while calcinated bone meal has an NPK ratio of 0-something-0, indicating no nitrogen and thus no protein.

Question: Is meat and bone meal safe to use in the garden? Answer: While MBM is sometimes used as a fertilizer, its use can be controversial. Some gardeners prefer to stick with pure bone meal to avoid attracting scavengers or introducing pathogens. Always ensure any product is properly sterilized.

Question: Why is some bone meal listed as 0% protein? Answer: Bone meal listed with 0% protein has undergone a high-heat calcination process that burns away all organic material, including the protein.

Question: How quickly does bone meal release protein? Answer: Any protein contained in steamed bone meal is released slowly as soil microbes break down the organic material over months. For animal feed, the digestibility is much faster.

Question: What are some vegan alternatives to bone meal for gardening? Answer: Mycorrhizal fungi, rock phosphate, and green sand are effective vegan alternatives for adding phosphorus and other minerals to soil.

Question: Does the protein quality differ between types of bone meal? Answer: Yes. The protein in meat and bone meal is a more complete and higher quality source for animal nutrition compared to the smaller, less digestible protein fraction found in steamed bone meal.

Frequently Asked Questions

Can I use bone meal as a protein supplement for my pets?

No. While some animal feed uses meat and bone meal, pure bone meal is not a protein source, and the safety and proper dosage of animal feed-grade supplements should be handled by a professional nutritionist.

Does bone meal provide nitrogen for plants?

Yes, steamed bone meal contains a small amount of nitrogen due to its protein content, but it is primarily a source of phosphorus and calcium.

How can I tell the difference between steamed and calcinated bone meal?

Steamed bone meal will typically have an NPK ratio with a small nitrogen number (e.g., 3-15-0), while calcinated bone meal has an NPK ratio of 0-something-0, indicating no nitrogen and thus no protein.

Is meat and bone meal safe to use in the garden?

While MBM is sometimes used as a fertilizer, its use can be controversial. Some gardeners prefer to stick with pure bone meal to avoid attracting scavengers or introducing pathogens. Always ensure any product is properly sterilized.

Why is some bone meal listed as 0% protein?

Bone meal listed with 0% protein has undergone a high-heat calcination process that burns away all organic material, including the protein.

How quickly does bone meal release protein?

Any protein contained in steamed bone meal is released slowly as soil microbes break down the organic material over months. For animal feed, the digestibility is much faster.

What are some vegan alternatives to bone meal for gardening?

Mycorrhizal fungi, rock phosphate, and green sand are effective vegan alternatives for adding phosphorus and other minerals to soil.

Does the protein quality differ between types of bone meal?

Yes. The protein in meat and bone meal is a more complete and higher quality source for animal nutrition compared to the smaller, less digestible protein fraction found in steamed bone meal.