What is the fat in butter? It's the fat produced from a 100% plant-based, high-fibre diet by an animal actually designed to eat one. It's what cellulose would become in our bodies if we (or rather our microbiota) could metabolise cellulose, plus the products of other fibres, starches and sugars in the grass, silage, or other feeds, and any fatty acids therein. One of these products of fermentation is butyric acid, incorprated in triglycerides as butyrate; butyrate makes up 3-4% of butter and is also formed in the human gut when dietary fibre is fermented by the right bacteria. Most of the benefits of fibre in the diet seem to relate to the formation of butyrate, and if the bacterial species present are those that instead prefer to generate D-lactate, or high levels of propionate, the results will not be beneficial - see the section "D-lactic and propionic acid - a cautionary tale" half-way down this probiotic review.
Pharmacological studies and siRNA knockdown experiments showed that NaB-mediated AMPK activation induced the phosphorylation and nuclear translocation of Sirtuin 1, leading to the increased assembly of mammalian TOR complex 2 and phosphorylation of AKT at Ser473 and subsequent induction of Nrf2 expression and activation. These favorable changes caused an obvious decrease in hepatic fibrous deposition, GST-P-positive foci development, and hepatocarcinogenesis.
Fat, therefore, is easy on the liver, and saturated fat the easiest of all, because the simplest to metabolize. I've shown in earlier posts how saturated (and monounsaturated) fats protect the liver because of their inherent stability compared to polyunsaturated fats, passively supporting the liver's antioxidant defenses. Butter also contains fats as MCTs, up to 15%, less than coconut oil, it's a source of vitamins A, D, E, and K2 as well as carotenoids, cholesterol and CLA. I'm sure there's another post in all this, but I've written more than enough already.