Dietary modification of milk saturated fatty acids
Attempts to modify the fatty acid profile of ruminant milk fat by reducing the proportion of saturated fatty acids (SFA) and increasing the proportion of unsaturated fatty acids (USFA) represent a challenge to animal nutritionists. Unsaturated fatty acids entering the rumen are extensively (typically 85 to 97% of poly-USFA) biohydrogenated to SFA by addition of hydrogen atoms to the double bond positions on the fatty acid chain. Hence, regardless of the fatty acid profile of the diet consumed, the predominant fatty acids leaving the rumen for delivery to the mammary gland are saturated C16:0 and C18:0 with only a small proportion of USFA.
Due to the difficulty of delivering USFA post-rumen, considerable research effort has been directed to development of technologies which provide ‘protection’ of fatty acids from ruminal biohydrogenation. In addition to increasing the bypass of USFA, feeding rumen-protected forms of USFA avoid the production of trans fats which can lead to substantial reductions in milk fat %.
Volac Wilmar’s Megalac rumen-protected fat contains around 45% USFA and is proven to reduce the SFA concentration in milk fat.