Just following up!
I weighed out what I feed in terms of grain and supplements, and had the pasture tested. We took soil samples on Sun and I’ll drop them off on Tues.
The estimated Iron intake (Grazing plus ration balancers) is 515 g, the zinc intake is 925 g, the copper is 164 g for about 1200 lbs horse, so about a 3.1 : 5.6 : 1 ratio. Does anyone have any comments? The copper does seem to be low, and ration balancer is balancing out the very low copper levels in the soil. I’ve been supplementing with manganese because it is low and the human vits were on sale. The bleaching has begun, but his black points stay black. His registration papers say “dark brown” but he maintains black points always.