An experiment was conducted to study the effect of providing additional Calcium (Ca) from different sources over and above that present in commercial layer feed on the performance of Rhode Island Red (RIR) laying hens. There were 4 treatment groups i.e. T1-Control-without additional Ca, T2-1% additional Ca from dicalcium phosphate(DCP), T3-1% additional Ca from calcium carbonate (CaCO3) and T4-1% additional Ca from limestone powder (LSP). Twentyfour number of RIR pullets of 20 weeks age were housed in individual cages and randomly allotted to 4 treatment groups. Each group consisted of 6 pullets. The experiment was conducted for a period of 20 weeks. Hens fed control diet had significantly (P<0.05) more feed intake than those fed 1% extra Ca from CaCO3 and LSP. Significantly higher Ca intake was recoded in hens of T2 group compared to those belonging to other groups. Egg number and % hen housed egg production was significantly higher in hens of T4 group compared to those of T1 and T3 group. Egg production was similar for hens fed 1% extra Ca from DCP and LSP. Significantly (P<0.01) heavier eggs were obtained in hens fed 1% extra Ca from CaCO3 compared to other groups. Feed conversion efficiency (Kg feed/dozen eggs) of hens fed LSP as additional Ca source was significantly (P<0.05) better compared to those fed control diet and 1% extra Ca from CaCO3. It is suggested that 1% additional Ca from LSP may be added to commercial poultry feed for better egg production with moderate size, early sexual maturity and better efficiency of feed utilization.
Calcium sources, egg production, performance, Rhode Island Red, laying hens
