Cows have natural light res of 50. Reducing their res is probably your most efficient way to deal more dmg.

Infis -85 lowers cows resists from +50 to -35. Since there are no immune cows (except king and other boss cows) which are broken by infi and have huge resists left i see no reason to use facets. -res from griffon and facets shine on broken immunity mobs, but you dont have them (except king and maybe 2 bosses per run).

well thank u for that great info
I alrdy went with facet'd all except occy
so that -15 from facets
-50 from infinity should be quick runs

Thats still 1,5/1,35 = 1,11... --> 11% more dmg from lowering their resists, not considering the +dmg% from facets. Seems as its still worth it, unless you oneshot already everything.

mostly use chain lightning so nothing get 1 shot