Just like cows have their similarities as well as extensive differences, so do the bypass fats. That’s why it’s very crucial to sort out the differences when choosing a bypass fat to effectively meet the challenges of Negative Energy Balance just after parturition. Currently three generations of bypass fats are used in lactating dairy cows:
First Generation Bypass Fat - Partially Hydrogenated Fats (PHFs)
Second Generation Bypass Fat - Calcium Soaps
Third Generation Bypass Fat - Pure Free Fatty Acids (FFAs)
Partially Hydrogenated Fats (PHFs) are animal or vegetable fats that have been hydrogenated to make them solid. Though this process reduces the level of unsaturated fatty acids to make the fat more rumen inert, it also decreases digestibility (40% or less).
Calcium soaps (84% Gross Fat) provide increased energy and improved digestibility over PHFs, but they contain 45% or more unsaturated fatty acids that upset rumen fermentation, reduce appetite, and depress dry matter intake.
Pure free fatty acids (100% Gross Fat), available as PurFAT, are the latest generation in dry fats. Fed in the form that the cow is naturally designed to digest, absorb, and use, it is the most inert in the rumen and without disturbing rumen function, is digested in the small intestine. Because of the fatty acid profile of PurFAT and high digestibility, cows maintain intake AND the intake is higher in energy. These fats high in saturated, long-chain, free fatty acids have the most positive impact on Negative Energy Balance.
Selection Criteria for Bypass Fat:
- Total energy content
- Effect on dry matter intake
- Digestibility
- Cost per unit of energy
- High concentration of Saturated Fatty Acids
