If you want a more detailed and accurate publication refer to the following link
http://www.fao.org/docrep/003/x6556e/X6556E00.htm#TOCthis is FAO ANIMAL PRODUCTION AND HEALTH PAPER 52
Small-scale sausage production by I.V. Savic
With reference to
Safe Practices for Sausage Production. Be careful with anything written by FSIS or the USDA, not that they are unreliable however, they have now combined as FSIS/USDA and at the present are doing a major overhaul of their publications. Most things still out there are linked through sites other than theirs. In a lot of the FSIS publications they were also numerous discrepencies.
hope that this is of some use to you
kind regards
Parson Snows