These birds are now coming up to 7 weeks of age, and were moved 6 days ago from the tractor into this pen (my worst as far as coccidia goes).
This pen has had umpteen chickens in it, but these birds are the youngest I've tried on that ground. It's my dampest pen, and is the one I'm going to see coccidiosis in if I see it at all. Since putting the birds in, it has rained twice.
You can see by the red combs (in the males, at least) that there are no signs of anaemia or pallor. All are eating heartily. Day 5 after exposure to heavy amounts of coccidia is when the first signs are seen... These birds are fine. The ones that look significantly smaller are much later hatched (about a week and a half); they were broody raised until 4 weeks of age, then put in the pen alongside the tractor-brooded ones.
So the roundup: one week on medicated starter; and 6 weeks on home mix.
The mix as you can see contains a range of whole and ground grains and legumes. However these birds aren't yet eating whole sunflower, so later in the day I'll go back and pick up what's left and toss it into the adult pen. By contrast the whole corn has been soaked and is beginning to sprout, and the whole wheat grains you can see are also sprouting. The young birds seem to be eating these very readily (helped probably by the container of hard grit nearby).
As far as cocci goes, I've never overcrowded the pen, so perhaps that's kept cocci levels from really shooting sky-high. As well, before these birds were put in the pen I tipped 2 wheelbarrow loads of woody mulch and raked it around (about 3cm thick), so it's arguable that the litter has helped reduce cocci exposure. Lastly regarding the pen floor it was also recently shovelled out to about 3cm depth to put on the garden, so that would have reduced cocci soil numbers somewhat.
But I've had the same circumstances (or nearly) when birds bought-in at point of lay from elsewhere acquired coccidiosis in this pen. Clearly the slightly improved pen floor can't be the reason why these birds are doing so well.
I'm left with two things: graduated exposure starting at day one in the brooder; removal of chicks from the brooder at exactly 3 weeks of age; further graduated exposure by moving the tractor weekly; and lastly and perhaps most importantly kefir.
The above mash contains about a litre and a half of kefir (soured milk) per bucketful of the following: soy meal (non GMO), pollard, bran, ground corn, ground sunflower, ground dun peas, wheat and corn sprouts, lucerne chaff (alfalfa), seaweed meal and salt.
Later in the day they get chopped greens, or I might hang something like kale or spinach in the pen.
Including organising the kefir and sprouts and grinding each day's corn/sunflower/peas, I spend about 20 minutes of a morning on all this. It isn't much considering the benefits (getting off the synthetic chemical roundabout, ensuring healthy birds/eggs/meat). And the longer I do it the more I learn.
What can be wrong with that?