Influence of two levels of phytic acid and particle size of oyster shell on the performance, calcium digestibility, gastrointestinal pH, and bone traits in broilers

ABSTRACT

1. Phytic acid (PA) is an antinutritional factor in poultry diets. The effect of high dietary PA in chicken diets might be exacerbated when the particle size of oyster shell (OS) is too fine. Thus, this study investigated the hypothesis that high PA with fine OS particle size would impair growth in broilers.

2. Two hundred and eighty Cobb 500 broilers were assigned to four diets in a 2 × 2 factorial arrangement in a CRD. The factors were PA (low or high) and OS particle size (fine or coarse) in starter, grower and finisher diets. Data collected were performance, Ca digestibility, gastrointestinal pH and bone traits.

3. On d 21, high PA increased intake (P < 0.05), gain (P = 0.099) and body weight (BW; P = 0.093) compared to low PA. On d 42, high PA increased BW (P = 0.086) and gain (P = 0.089) compared to low PA. High PA increased intake (P = 0.063), BW (P = 0.054) and gain (P = 0.056) compared to low PA on d 56. High PA improved liveability on d 56 (P < 0.05) compared to low PA. In birds fed coarse OS, crop and ileal pH were reduced (P < 0.05) by high PA on d 28. The OS × PA interaction was observed for ileal pH (P < 0.05) on d 56, where in birds fed coarse OS, low PA increased ileal pH. Fine OS increased crop (P = 0.056) and proventriculus pH (P < 0.05) on d 56. There were no treatment effects on calcium digestibility. In birds fed fine OS, high PA decreased the BS (P < 0.05).

4. Overall, the study showed that a combination of high PA and coarse OS particle size improves the production performance of broilers, while low PA and coarse OS improve their bone health.

KEYWORDS:

• Phytic acid
• oyster shell
• particle size
• growth performance
• bone health and broilers

Acknowledgments

The authors hereby acknowledge AB Vista, Marlborough, UK for funding this research and the General Chemistry Laboratory of the CSIR-Food Research Institute of Ghana for their technical assistance in the analysis of the TiO₂, Ca and P. Mr. Haruna Seidu of the Forestry Research Institute of Ghana, Fumesua is also duly acknowledged for his technical assistance in the use of the universal texture analyser.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by AB Vista, UK.