Calcium and phosphorus both are needed in conjunction with each other for egg shells. Four times the amount of ca. is needed during laying season than the rest of the year. My ration we figure the peahens needs between 1.90-2.30 grams of calcium per day and .4-.6 grams of phosphorus daily. We're actually making it in the 3 grams daily intake of calcium and the .75 gram of ph. per day,,,,if they are getting excess they will just poop it out as with anything unneeded in their diets, vitamins and mineral and protein wise.