What is the reason why you don't want to feed layer pellets? Laying chickens need the correct balance of carbohydrates, proteins, minerals and fats. The commercial feeds have these at the right levels and make a complete feed with nothing else required except water. Rice does not contain enough protein which is essential for the production of eggs and the growth of new feathers. Nor does it contain sufficient calcium. If you want to provide alternative feeds you will have to provide mineral and protein rich foods along with something like rice or corn for carbs and a little fat particularly in the winter. Bird seed is rich in carbs possibly protein depending on seed type and some minerals but are hard to digest and must be fed with grit. They also do no contain enough calcium.