A comparative study on the effect of limestone particle size on performance, ileal digestibility of calcium and phosphorus, and bone characteristics in broilers and pullets

ABSTRACT

1. The effects of limestone particle size on growth performance, gastrointestinal tract (GIT) traits, ileal morphology, duodenal gene expression of calbindin, apparent ileal digestibility coefficients (AIDC) of calcium (Ca) and phosphorus (P) and tibia characteristics in broilers and pullets were assessed in broilers and pullets. These birds have different growth rates and likely different responses to parameters, such as particle size.

2. A total of 240 chicks aged one day, 120 Ross 308 female broilers, and 120 Hy-Line pullets were allocated randomly into four treatments in a 2 × 2 factorial arrangement with two bird types (broilers vs. pullets) and two limestone particle sizes (<0.5 mm versus 1–2 mm) to give six replicates containing 10 chicks in each from 1 to 21 d of age.

3. Feed intake and weight gain were greater (P < 0.001) and feed per gain (FCR) was better (P < 0.001) in broilers compared to pullets from 1 to 21 d of age. Greater villus width (P < 0.01), villus height (P < 0.001) and crypt depth (P < 0.01) were seen for broilers compared to pullets.

4. Pullets fed coarse Ca particles had higher calbindin gene expression at 21 d of age (P = 0.05). Both AIDC of Ca and P were higher (P < 0.001) in broilers compared to pullets. The AIDC of Ca from 0.463 to 0.516 was increased (P < 0.05) by feeding coarse limestone particles. A significant interaction was found between bird type and limestone particle size (P < 0.01), where pullets fed coarse Ca particles had higher bone P concentration in tibia than broilers.

5. Broilers had better ileum absorptive capacity and growth performance compared to pullets. The AIDC of Ca and P was higher in broilers than in pullets. Increased limestone particle size elevated villus height, AIDC of Ca and concentration of P in the tibia.

KEYWORDS:

• Digestion
• gastrointestinal tract
• morphology
• poultry
• tibia

Acknowledgments

The authors thank the personnel of the Poultry Research Unit of Bu-Ali Sina University for the care of birds.

Disclosure statement

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

Author statement

A.R. Jafari Arvari, S. Mirzaie Goudarzi, M. R. Abdollahi and M. Sadeghi conceptualised the experiment. A. R. Jafari Arvari conducted the animal part of the experiment. S. Mirzaie Goudarzi also supervised the project. A. R. Jafari Arvari and S. Mirzaie Goudarzi analysed the data and wrote the first draft of the manuscript. M. R. Abdollahi contributed to the data interpretation and proofreading of the manuscript. M. Sadeghi contributed to the extraction of gene expression data and their interpretation. All authors contributed to the editing and approval of the final version of the manuscript.

Ethics statement

The authors confirm that the ethical policies of the journal, as noted on the journal’s Guidelines page, have been adhered to.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.