According to an analysis from Sniffen (2004) where feeding 5 pounds of cottonseed was compared to feeding 1 pound of a CA salt supplement, cottonseed showed an advantage on milk fat, with 3.7% milk fat for cottonseed vs. 3.54% for CA Salts. However, the research also showed that they are really apples and oranges when it comes to their impact on milk yield, with CA-salts yielding 5.7 pounds of milk versus just .7 pounds of milk for cottonseed.
Therefore, the difference in fat corrected milk is…5.74 pounds for CA Salts versus just .72 pounds for cottonseed, giving CA Salts a 5-pound energy corrected milk advantage.
What’s the bottom line?
1) Remember that not all ‘fat supplements’ are the same.
2) Whole cottonseed is a valuable jack of all trades, but not a pure substitute for the energy value for fat corrected milk that your rumen inert fats like EnerGII provide.