Adding an economic value to leftover meat bones.

Millions of tons of animal by-products are produced annually in Kenya. Very many people especially butchers and eateries that trade I meat products have an endless supply of bones that at times end up being a nuisance to their businesses.

But did you know that those bone leftovers are a real treasure?

Often the skeletal system (bones) is separated from meat during the processing of meat. Bone meal is an organic fertiliser that is a good source of phosphorus while for animals, it supplies mainly proteins. 

More recently, researchers at South Carolina's Clemson University have been looking at the use of meat and bone meal in petroleum-free bioplastics that can be used in items such as skis and snowboards.

Bone meal as used in animal feed.

Meat and bone meal is an excellent source of protein. Meat meal is an animal feed produced by recycling animal by-products. These by-products are cooked, or “rendered,” to produce a nutritional and economical feed ingredient.

When these raw waste materials are subjected to the rendering process, the result is many valuable and useful products, from bone meal to poultry meal, which are then used as feed ingredients for cattle, poultry and pets.

Meat and bone meal (MRM) and blood meal are valuable products that can be sold for use in the pet food industry, feed industry and other industries. The fats from the rendering process can also be used in the pharmaceutical, chemical and oil industries, as well as many others.

MBM is an excellent source of protein, calcium phosphorous, vitamin B-12 and numerous other minerals that are necessary to an animal’s health. In poultry diets, meat and bone meal is typically limited to less than 5% of the diet content because of the high calcium, phosphorus, and lysine content of the meal.

In order for animal by-products to be used in other materials and processes, the by-products must first be treated. Bone meal, meat meal and blood meal are produced in a process known as rendering. In this process, the raw material is heated to remove moisture and release fat.

For the dry bones, they are crushed with some of the innards and boiled under high temperatures of between 350 and 400°C to kill any pathogens that include salmonella contaminants.

The dry rendering process often begins with crushing and grinding the material, followed by heat treatment to reduce moisture content and eliminate any microorganisms. The melted fat is then separated from the solid protein through draining and pressing, and the solid material is ground into powder, such as meat meal, meat and bone meal, feather meal and blood meal.

Using bone meal as fertiliser.

Bone meal as fertiliser is that it is very high in phosphorous. As we all do agree, majority of these synthetic chemicals are bad for the soil as well as the produce we ingest.

Supplying your soil with organics like bone meal will help to nourish your soil without the added man-made chemicals. Chicken bones are great for this purpose. Whole chicken bones alone can be great for the soil, but the breaking-down process takes so long that it will just rob the soil of other nutrients.

How to make bone meal fertiliser.

1. Start off by collecting bones until you have a sufficient amount. 
2. The next step is to make broth to clean and sterilise them. Cover bones with water to the ⅔ mark. Add a splash of vinegar and a couple teaspoons of salt. Lock lid, and make sure steam valve is in the closed position. Cook on the “Soup” setting for two hours then drain broth and repeat for a second batch. By the end of this time, the bones will easily strip clean of any fat or meat tissue still stuck to them. 
3. Dry the bones. Once stripped clean, spread the bones on a plate and place them in a well-ventilated area to dry. Normally, this can take about a month for the bones to dry completely. This makes it easy to turn into a powder. 
4. Once the bones are brittle and dry, crush them into a fine powder. The best way to achieve this is with some muscle and a mortar and pestle. Work small batches at a time to create an evenly fine powder. 
5. Once ground up, the homemade bone meal for plants is now ready to use. You can store in tightly-sealed containers in a cool place. Bone meal lasts very well, and isn’t prone to clumping.