Abstract

Background: Small-scale quail farmers commonly use semi-self-mixed diets that may reduce mineral availability and compromise laying performance. Locally sourced calcite could provide a cheaper, more effective alternative to commercial mineral premixes.
Objectives: This study evaluated the effects of locally formulated calcite-based mineral supplements that differed in particle size, calcination, and mineral enrichment on the productivity, physiological responses, and economic efficiency of laying quails.
Materials and Methods: Five local calcite-based mineral formulas were produced from rock flour and oyster shell meal in raw or calcined forms, with or without mineral enrichment. A total of 432 laying quails were assigned to six dietary treatments, including a commercial mineral premix and five local mineral supplements incorporated at 5% of the basal diet for eight weeks. Productive performance, eggshell quality, blood mineral profile, physical characteristics of the minerals, and economic returns were evaluated.
Results: Local calcite-based minerals significantly improved egg production, egg mass, feed conversion ratio, and net return compared with the commercial premix (p < 0.05). Calcite grit (Cag) produced the highest productivity and profitability. Its coarse particle size and greater density likely enhanced calcium retention and sustained mineral release for eggshell formation. Although calcination and mineral enrichment increased serum phosphorus levels, they did not further improve production performance or economic efficiency.
Conclusions: Calcite grit is an effective and economically superior mineral supplement for laying quails. Physical characteristics, particularly coarse particle size and density, contributed more to productive performance than calcination or mineral enrichment.

Key words: Calcite grit; calcination; Coturnix japonica; net return; physical property