Taming a equus is a passive tame not a knock out. You'll need to make a trap so it won't run off and get killed. You'll need as much berries as the DeX says. And have a ghillie suit to not spook it.But in case you accidently mount off and lose some taming effect have some more berries with you just in case. This is how I did it.
Well the Equus is a hard tame,even a t-rex is easier but you will need around 30-60 carrots so to get that you will have to plant some get a medium plant crop and in order to the seeds go to the nearest forest and keep gathering plants until you get the seeds plant the seeds with fertilizer inside the plant crops.