That's all good information to work with, thank you for the answers. Sorry I didn't get back to this faster, but I had lost track of the thread a bit and then it seemed to have blown up and I wasn't sure you were going to be coming back to read.
Which of the birds (breed wise) had started to lay? Were the brahmas actively laying and stopped as well or just the ones that had started are included in the ones that stopped? You mention you are feeling laying pellets "now" - was that a recent change and, if so, how recently was it changed? Given the ages involved I would imagine those that had started did not lay very long at all prior to stopping as it's been two weeks since they stopped laying - how many days/weeks was it you actually got any eggs from them?
Not to belabor the point, but the fact is that your birds are in a situation where the space available to them is not optimal. You have about 1.5 square feet in the coop and 5 square feet per bird in the run given the measurements you've given (and that's assuming that your feed and water stations are located such that they are not occupying any of the internal space). While industrial poultry farming will often assert that such an amount of space is sufficient, or even generous in comparison with the conditions of battery birds, from a practical standpoint it could definitely give you happier, healthier birds to increase the amount of space the birds have to themselves. A more commonly accepted guideline (outside of commercial producition or the horribly misguided measurements quoted by the pre-fab coop industry) is to try to allow at least 4 square feet inside and 10 square feet outside for each bird for standard large fowl birds - more for larger breeds (which you do have). While birds can certainly survive in less space than that, the goal (especially when you are wanting to increase production) is to have them thrive - rather than looking at meeting minimum standards, providing more than squeaking by (or cramming in).
Really, most of your birds are still very much within the window where a lack of production is not all that concerning - except for those birds that did start and then stopped. While starts and stops are normal when a bird first enters production, the fact that it has been two weeks with no eggs is a bit outside the norm for even the rather erratic production you can see at first. There are many factors that can contribute to a lack of production - for your birds it may be that most of them (after all, 15 out of 200 total is not that many birds to have seen start/stop and assume there is a more generalized/flock-wide problem) simply are not yet ready. You have a bit of a mix of breeds as far as the expected point of maturity. Do you ahve photos of the birds that you can share so that we can help you assess where they are in regards to closeness to production? If the birds truly are at the point where they *should* be producing and are not, that is when you start looking at the other factors that can cause issues - internal/external parasites, stress, nutritional issues, etc.
