Effects of fat supplements containing different levels of palmitic and stearic acid on milk production and fatty acid digestibility in lactating dairy cows

Fat supplements based on palmitic acid (PA) or stearic (SA) are expected to have different effects milk production and nutrient metabolism in lactating dairy cows. In this study, the of prilled fat containing levels PA SA were tested 12 high-producing multiparous cows (pretrial yield = 53.4 ± 8.7 kg/d; mean SD) arranged a 4 × Latin square design with 21-d periods. Treatments control (CON; no supplemental fat), an enriched supplement (HP; 91% C16:0), (HS; 92.5% C18:0), blend (INT) fed at 1.95% diet dry matter. All contained oleic approximately 5% fatty acids. The HP treatment decreased matter intake (DMI) by 1.9 kg/d 1.1 compared CON, respectively. Milk was not changed treatment, but INT increased energy-corrected 2.7 HS. treatments 0.11 0.14 Additionally, <16 carbon acids (FA; de novo synthesized) 44 g/d 43 16-carbon FA (mixed source) 155 CON 64 relative INT. No effect apparent total-tract digestibility matter, organic neutral detergent fiber detectable. HS 10.3 10.5 percentage units HP, Total-tract 18-carbon lowest highest HP. conclusion, supplementing SA, mixture without decreasing intake. profile influences their DMI synthesis.