Cows Need Both C 16 and C 18 Fatty Acids

During the past decade, fatty acid (FA) research has been focused on discovering the optimal combination of FA to feed to lactating cows for the purpose of improving milk yield (MY) and milk components. Most long chain fatty acid (LCFA) supplements contain either combinations of palmitic (C16:0) and oleic acids (C18:1), highly enriched C16:0 (>80%), or C16:0, stearic acid (C18:0), and C18:1. These supplement categories have substantial published research trials over the past 30 years. Nutritionists, researchers, and dairymen are continuing to search for the most optimal combination of these three LCFA. New information continues to enhance our knowledge of the metabolism and utilization of these LCFA for the purpose of improving MY, milk fat (MF), milk protein (MP), and reproduction by improving energy balance (EB) in early lactation. These LCFA are intimately involved in the metabolism of the lactating cow and have specific functions in the production of milk and milk components. Palmitic acid has been shown to improve milk fat % and yield. However, supplementing C16:0 has no effect on MY, body weight gain or body condition score (BCS). Stearic acid has been observed to have a positive influence on dry matter intake (DMI) and the yield of milk, MF, MP, and milk lactose. Combinations of C16:0 and C18:0 have been shown to improve MY, milk components, and improve EB in early lactation. Thus, the importance in discovering the proper ratio and feeding rates of these LCFA to improve performance is of interest.