Use of extruded eggshell as a calcium source substituting limestone or oyster shell in the diet of laying hens

Abstract

The nutritional values of limestone, oyster shell and extruded eggshells were evaluated using different methods. In total, 120 ready-to-lay pullets, 18-week-old ISA Brown were distributed into six dietary groups, namely D1 (4% limestone), D2 (8% limestone), D3 (4% oyster shell), D4 (8% oyster shell), D5 (4% eggshell) and D6 (8% eggshell), to assess the effect of calcium sources on egg production, egg quality, dry matter and cholesterol content of the egg. Kitchen-extruded eggshell contained 98.52, 4.24, 29.75 and 14.82% DM, CP, Ca and P, whereas hatchery-extruded eggshell contained 99.20, 13.80, 25.53 and 13.87% DM, CP, Ca and P, respectively. Limestone and Oyster shells contained 99.60 and 99.51% DM, and 37.12 and 35.20% Ca, respectively. Body weight, egg, hen day and egg mass production, and FCR did not differ among diets (p >.05). Egg production tended to increase with the increase of hen-housed egg production (p