Fatty acid (FA) supplements containing palmitic acid (PA) are often included in lactating cow diets to increase diet energy. Previous publications have shown that PA supplements with moderate enrichment (~85%) have a higher digestibility compared with those that are very highly enriched (≥98%). Saturated FA have the potential to form organized secondary structures, which may attribute to their change in digestibility. Differential scanning calorimetry (DSC) is a thermal technique used to analyze changes in heat flow as energy is absorbed or released from a sample during heating. In the current project, DSC was used to determine melting temperature (MT) and enthalpy, a measure of energy flow during melting. Our hypothesis was that MT and enthalpy would increase as the enrichment of PA supplements increased. Supplements containing approximately 55, 80, 95, 98, and 99% C16:0 were analyzed using a Q600 STD (TA Instruments). Briefly, a ~40-mg sample was heated at 5°C/min from 25°C to 110°C. Instrument software (TA Universal Analysis, TA Instruments) was used to determine MT and total enthalpy of melting (area under the curve). Treatment means were compared with a Protected LSD Test in a model that included the fixed effect of PA enrichment. Melting temperature for the 55, 80, 95, 98, and 99% categories was 60.9, 65.6, 66.5, 67.3, and 68.1°C, respectively. These supplements also had enthalpy values of 196.0, 199.8, 217.4, 221.7, and 218.8 mW, respectively. The MT of the 55% category was lower than all others, but there was no difference between 80 and 95% or 98 and 99% (P < 0.0001). Both the 55 and 80% decreased enthalpy compared with the 95, 98, and 99% (P < 0.0001), but was not different between the 3 most enriched supplements. This data indicates large differences in physical characteristics of fat supplements differing in PA enrichment, but only minimal differences between those exceeding 95% enrichment in PA. These physical characteristics may explain differences in digestibility, although more work is needed to understand this relationship.