^Milk production varies due to a significant range of variables including age of the cow, time of year, climate conditions, type of feed and specific breed lineages. Particular attention should be made to citations for figures used in this table for the methods used to obtain these average figures.
^ abcdefghijHeinrichs, Jud; Jones, Coleen M.; Bailey, Ken. "Milk Components: Understanding Milk Fat and Protein Variation in Your Dairy Herd". PennState Extension. Penn State College of Agricultural Sciences. Retrieved 2022-06-13.