So far, so good! These layer chicks are growing more and more robust and active by the day.
When first bought they were clearly showing signs of early coccidiosis, albeit very mild. This means they'd had some exposure before arriving here, though none was very sick. All came good after a day or two with a warm night-hutch and medicated starter.
After a few weeks in a brooder I'd seeded with older layer droppings they went onto a tractor on ground that I'd used to raise the meat hybrids. I left them in the tractor on the same ground for a week, longer than intended but still with commercial starter alongside other food. I left them there this long as I wanted the grass and weed cover eaten down. By the time it was close to ground level I moved the tractor.
Remember, the hybrids were on this ground when they showed cocci signs, so I'm going to go all-out and say these layers have now been quite heavily exposed. What they haven't been, however, is overwhelmed.
Some factors may be at play here:
- they're still consuming medicated starter. However I've noticed that they much prefer my home mix containing kefir, to the extent that I've barely had to add to the commercial starter hopper at all. I'd say they're only eating minimal amounts of medication, if any.
- the kefir may be providing some anti-coccidial benefits. Milk has long been used in this way, though I don't know to what degree it is generally effective. However when my meat hybrids developed coccidiosis they weren't having much kefir at all, as I hadn't begun souring skim milk for them. It remains possible that the kefir is a good preventive.
- the weather has been quite a bit drier than when I put the meat hybrids onto the same ground. However there have been two days of light rain and I would have expected to see some coccidiosis by now if the chicks were going to show signs. As well, the weather while raising the meat chicks was quite a bit cooler than now (warmth is important to oocyst ripening). Thus I'm not sure weather has been an important factor.
- these chicks may have been effectively 'inocculated' by their earlier mild bout of cocci. However only a few of the chicks seemed to have symptoms when I bought them, and I'm not sure the exposure was large enough to develop a full immune response. Still, it's quite possible that this alone explains their hardiness now.
It's hard to make judgements from all this, except that I can say that the combination of the above seems to prevent coccidiosis! Obvious, I know... Graduated exposure has always been the key to cocci prevention, however one achieves it (e.g. ionophores work by allowing some exposure but limiting it so the bird still acquires immunity). But still, 20 chicks aged about 6 weeks in a tractor on dampish ground for a whole week without cocci and with only very minor use of ionophores isn't bad.
The next step is to stop leaving chick starter out for the birds, and move fully to unmedicated feeds, whether I use my own mix or add in commercial meat bird finisher (also 18%) to cover my nutritional bases.