We use everything we can from the animals we butcher out of respect for the life of that animal, every butchering is a zero waste event for us.
It’s a simple task to catch blood from a small animal that is hanging, like poultry in a killing cone, or a stunned rabbit by its feet, so I never pass up the opportunity to catch the blood in a bucket and use it. I occasionally catch it for culinary use, making blood sausage or blood pasta, but most often I catch it in a bucket, dilute it with water to keep it fluid and use it when watering leafy greens in the garden.

In this case it was rabbits that were butchered, and I caught the blood in a 5 gallon bucket and diluted it with water, about a 50/50 ratio. From there the diluted blood goes through a strainer to strain out fur and blood clots so it can be used in one of our EZ Flow Fertigators without clogging it. The EZ Flow is hooked up to a garden hose which further dilutes it and doses the plants we choose to use it on. Adding it to the crops in that manner dilutes the strong smell of blood which can attract unwanted nocturnal predators to the farm.
The NPK of blood is 12-0-0, which is the highest percentage of organic nitrogen there is, and it's full of micro-nutrients, especially iron. Using it to feed plants that you want spectacular leafy green growth on kale, collards, lettuce etc. is a great way to utilize this resource which is at your disposal if you're someone who does backyard butchering. You can also do a strong dilution of 75% water to 25% blood ratio in a 5 gallon bucket and add it directly to your compost pile. If you want to amp it up even more, adding more nutrients to mix, you can add some rabbit manure to the bucket and/or comfrey leaves, let the bucket sit for 72 hours, stirring it daily, then strain out the solids before using it in the garden.
Making blood meal for the garden
In the spring and summer it’s easy to use fresh, diluted blood in a the EZ Flow, but in winter time there’s no need for it in the garden, so I dehydrate it and store it for use when spring rolls around.

I use a plastic sheet that came with my Excalibur dehydrator to dry the blood on, and once it’s dried I run it through my blender to powder it, then jar it up and store it until we’re ready to use it.

When the warmer weather starts, we add the blood meal to the EZ Flow with X amount of water and it's good to go.
Zero waste with every butchering.