Published online by Cambridge University Press: 27 March 2009
1. The daily retention of calcium, carbonate, phosphorus and chloride was studied using four birds and changing the calcium carbonate content of the ration every 5 days for 15 days.
2. It was shown that high calcium diets result in a much lower retention of calcium and thin-shelled eggs are produced.
3. Retention of calcium was higher in the laying than in the non-laying bird when calcium carbonate was fed.
4. High calcium diets depressed the retention of phosphorus, and in one case the retention was negative, even when no eggs were laid. Laying birds gave negative values for retention because of the heavy phosphorus excretion associated with egg laying.
5. High calcium diets also depressed the retention of chloride, and on occasion led to negative retention values.