Indian Journal of Poultry Science

An experiment was conducted to study the effect of feeding different levels and particle size of calcium (Ca) supplement on performance, egg shell, quality and serum calcium (Ca) and phosphorus (P) concentrations in White Leghorn (WL) layers. Nine experimental diets were prepared with 3 Ca levels (2.75, 3.25 and 3.75%) and 3 particle sizes (2–4, 4–6 and 6-8mm) of Ca supplement as oyster shell grit in maize-soybean meal and deoiled rice bran based diet containing 0.49% available P. Levels of shell grit were adjusted to arrive at the desired levels of Ca in the diets. A total of 270 WL pullets (24 weeks of age) were randomly divided in to 9 dietary treatment groups of 30 birds each and housed in individual cages under similar management. Each experimental group were replicated three times at the rate of 10 birds in each. Each diet was fed ad libitum up to 37 weeks of age. Significantly (P<0.05) higher egg production was observed at 2.75% Ca compared to other higher levels of Ca. Serum Ca concentrations increased significantly (P<0.05) with increasing the dietary levels of Ca from 2.75 to 3.25%. The Ca concentrations in diet did not influence feed intake, feed efficiency ration, egg weight, shell quality and P concentration in serum. The above traits did not influence significantly due to particle size and interaction between particle size and Ca levels. Based on the results, it can be concluded that White Leghorn layers (24 to 37 weeks of age) do not require more than 2.75% Ca in diet when oyster shell grit was used as Ca supplement with 2–4 mm particle size.