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ORIGINAL RESEARCH article
Front. Vet. Sci.
Sec. Animal Nutrition and Metabolism
Volume 12 - 2025 |
doi: 10.3389/fvets.2025.1489948
The Impact of Dietary Phosphorus Levels on Growth, Slaughter, and Digestive Metabolism in Growing Sheep
Provisionally accepted- 1 Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
- 2 Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province, China
- 3 Chongqing Academy of Animal Science, Chongqing, Chongqing, China
Phosphorus (P) pollution from livestock farming poses significant environmental challenges, necessitating efficient P utilization. This study systematically investigated the effects of varying dietary P levels on growth, slaughter performance, nutrient digestion, and metabolism in Yunnan Semi-fine Wool Sheep during the growth phase. Forty-five sheep (30.33 ± 0.56 kg) were randomly assigned to five dietary P levels (0.40%, 0.51%, 0.68%, 0.82%, and 0.97%) over a 44-day trial, including a 14-day pre-feeding and 30-day formal trial period. Digestibility trials were conducted on days 22-27, and selected sheep were slaughtered for detailed analysis. Results showed no significant effects of dietary P on daily weight gain, feed-to-gain ratio, or organ indices (P > 0.05). However, dry matter intake, liver, and lung weights decreased linearly with increasing P levels (P < 0.05). Carcass traits such as left half carcass rate and net rib rate varied significantly (P < 0.05), showing quadratic trends. P levels also affected P, calcium, protein, and energy metabolism, as well as apparent digestibility of acid detergent fiber (P < 0.05). Using endogenous loss and comparative slaughter methods, the P maintenance requirement was determined as: Retained P = 0.5436 × Intake P -0.0614 (R² = 0.83, P < 0.01). P requirements for growth were modeled as: P (g/kg EBW) = 30.95772 × EBW -0.5031. The recommended dietary P level was 0.40%, with maintenance and growth requirements of 0.06 g/EBW and 5.34-6.19 g/kg EBW, respectively, providing a foundation for P reduction strategies.
Keywords: Sheep, growth performance, slaughtering measurements, Metabolism, Phosphorus requirement
Received: 02 Sep 2024; Accepted: 09 Jan 2025.
Copyright: © 2025 Zhao, Ni, Zhou, Wang, Wen, Zhao, Cao, Zhao, Shao, Lu, Chen, Zhang, Yang, Quan and Xue. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Guobo Quan, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province, China
Bai Xue, Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, China
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