Everything you need to know about fat & sausages? - NZ Casings NZ
https://nzcasings.co.nz/blogs/sausage-making-blog/why-is-fat-so-important-for-sausages#:~:text=Sausages%20should%20contain%2025-30%25%20fat.%20This%20may%20seem,250-300g%20of%20fat%20per%201kg%20of%20sausage%20mix.
The fat content of sausages can vary depending on the type, ingredients, and cooking method. A general ratio of fat to lean in sausages is about 25% fat to 75% lean12, but some commercially made sausages can contain up to 50% fat1. The fat content of sausages can range from 3.8g to 18.4g per 100g3, or 8g per sausage patty4. The fat content affects the flavor, moisture, and calories of sausages.