Endogenous phosphorus losses and standardized ileal digestibility of phosphorus in layer hens fed purified diets with diverse phosphorus sources

Venuste Maniraguha¹, Shan Randima Nawarathne¹, Elijah Ogola Oketch¹, Nuwan Chamara Chathuranga¹, Bernadette Sta. Cruz¹, Jeseok Lee¹, Haeeun Park¹, Hyunji Choi¹, Yu Bin Kim¹, Jung Min Heo¹^,^*, Myunghwan Yu¹^,^**

¹Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 34134, Korea.

^*Corresponding Author: Jung Min Heo, Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 34134, Korea, Republic of. Phone: +82-42-821-5777. E-mail: jmheo@cnu.ac.kr.

^**Corresponding Author: Myunghwan Yu, Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 34134, Korea, Republic of. Phone: +82-42-821-7022. E-mail: tomymh@cnu.ac.kr.

© Copyright 2025 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Jan 02, 2025; Revised: Jan 24, 2025; Accepted: Jan 27, 2025

Published Online: Feb 04, 2025

Abstract

This study aimed to measure the endogenous losses, the apparent (AID), and the standard ileal digestibility (SID) of phosphorus (P) using a diet containing corn, soybean meal, and wheat bran in 45-week-old Hy-line Brown laying hens. Hens were fed experimental diets containing inorganic phosphate supplements and plant-based phosphorus sources. Experimental diets included: (i) inorganic phosphate supplements (monocalcium phosphate [MCP], dicalcium phosphate [DCP], monosodium phosphate [MSP]); (ii) plant-based phosphorus sources (corn [CRN], soybean meal [SBM], and wheat bran [WB]); and (iii) a phosphorus-free diet [P-free]. Measurements were collected from the ileum and excreta over three days with six replicates per dietary treatment and four hens per cage, under <italic>ad libitum</italic> feeding conditions. The study demonstrated interactions (<italic>p</italic> < 0.05) between diet type and sampling locations on endogenous phosphorus losses. Higher endogenous phosphorus losses (<italic>p</italic> < 0.05) were observed in the excreta of hens fed P-free, MCP, DCP, MSP, and WB diets. Increased endogenous P losses in the ileum (<italic>p</italic> < 0.05) were noted in hens-fed CRN, SBM, and WB diets compared to inorganic phosphate supplement diets. The AID and SID of P were significantly lower (<italic>p</italic> < 0.05) in the CRN diet compared to SBM, WB, MCP, DCP, and MSP diets. Among inorganic phosphate supplements, MCP exhibited the highest SID of P, while for plant-based sources, SBM and WB demonstrated higher SID values than CRN. The AID of P was higher (<italic>p</italic> < 0.05) in hens fed the MCP diet compared to SBM and WB diets, but diet type did not affect the AID of dry matter (<italic>p</italic> > 0.05). In conclusion, diet type and sampling location influence endogenous P losses in laying hens, with differences between ileal and excreta measurements. The results highlight the variability in P bioavailability among plant-based and inorganic phosphorus sources, emphasizing the need to account for ingredient-specific P digestibility when formulating diets for optimal P utilization.

Keywords: Digestibility; endogenous losses; excreta; laying hens; phosphorus