My trimmer told me that they're just cosmetic & are to do with moisture levels. When the weather is wet (&makes the hooves constantly wet), the hooves absorb the moisture, expand slightly & the cracks seem to disappear (they haven't though - it's just because the hooves have expanded). When the weather is dry like it is now, the hooves are also dry, so contract slightly & look like that. That's what i was told - no idea how true it is? Ours have no problems resulting from them though. They're only superficial surface cracks. Mine are all on balanced minerals & live out. The cracks definitely seem to be weather-related.
Some people soak the hooves with water but i read a study that said it made no significant difference to hoof moisture levels.
I'd be interested in other responses too as I've just taken my trimmers' word for it
Those are more than superficial esp when tied in with the event lines. It's a good balancer but might not be the right one for you, plus I suspect the grass maybe too much. The deep toe crack is not just a trimming issue. A photo of the sole would help but it is possible the white line has become stretched.
The surface cracks tend to appear in hooves with sub optimal nutrition - this can be mineral balance or excess dietary sugar (grass is usually the main culprit).
I'd say the large crack may well have some seedy toe lurking underneath... has your trimmer had a look, or advised any treatment for it?
Yes there is a lot of grass coming through, she is strip grazed and the grass they get is about a foot long which I understand is better than short ? Maybe I need to give them less per day.