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ORIGINAL RESEARCH article

Front. Immunol.
Sec. Microbial Immunology
Volume 15 - 2024 | doi: 10.3389/fimmu.2024.1398310

Dietary 5-Hydroxytryptophan improves sheep growth performance by enhancing ruminal functions, antioxidant capacity, and tryptophan metabolism: In vitro and in vivo studies

Provisionally accepted
Zhe Sun Zhe Sun 1Natnael D. Aschalew Natnael D. Aschalew 1Long Cheng Long Cheng 1Yuanhong Xia Yuanhong Xia 1Longyu Zhang Longyu Zhang 1Guopei Yin Guopei Yin 1Shikun Wang Shikun Wang 2Ziyuan Wang Ziyuan Wang 1Jianan Dong Jianan Dong 1Weigang Zhang Weigang Zhang 3Wei Zhao Wei Zhao 3Guixin Qin Guixin Qin 1Xuefeng Zhang Xuefeng Zhang 1Rongzhen Zhong Rongzhen Zhong 4Yuguo Zhen Yuguo Zhen 1Tao Wang Tao Wang 1*
  • 1 College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin Province, China
  • 2 College of Life Sciences, Jilin Agricultural University, Changchun, Jilin Province, China
  • 3 Changchun Borui Science & Technology Co., Ltd, Changchun, Hebei Province, China
  • 4 Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences (CAS), Harbin, Jilin Province, China

The final, formatted version of the article will be published soon.

    Hydroxytryptophan (5-HTP) can regulate the synthesis of 5-Hydroxytryptamine (5-HT) and melatonin (MT). In a previous metabolome analysis, we found that 5-HTP is an effective ingredient in yeast culture for regulating rumen fermentation. However, research on the effect of this microbial product (5-HTP) as a functional feed additive in sheep production is still not well explained. Therefore, this study examined the effects of 5-HTP on sheep rumen function and growth performance using in vitro and in vivo models. Firstly, a two-factor in vitro experiment involving different 5-HTP doses and fermentation times was conducted. Then, in the in vivo experiment, 10 sheep were divided into a control group which was fed a basal diet, and a 5-HTP group supplemented with 8 mg/kg 5-HTP for 60 days. The results showed that 5-HTP supplementation had a significant effect on in vitro DMD, pH, NH3-N, acetic acid, propionic acid, and TVFA concentrations. 5-HTP altered rumen bacteria composition and diversity indices including Chao1, Shannon, and Simpson. Moreover, the in vivo study on sheep confirmed that supplementing with 8 mg/kg of 5-HTP improved rumen fermentation efficiency and microbial composition. This led to enhanced sheep growth performance and increased involvement in the tryptophan metabolic pathway, suggesting potential benefits. Therefore, dietary 5-HTP (8 mg/kg DM) improves sheep growth performance by enhancing ruminal functions, antioxidant capacity, and tryptophan metabolism. This study can provide a foundation for the development of 5-HTP as a functional feed additive in ruminants’ production.

    Keywords: 5-Hydroxytryptophan, Sheep, ruminal fermentation, microbiota, growth performance, Metabolites

    Received: 09 Mar 2024; Accepted: 03 May 2024.

    Copyright: © 2024 Sun, Aschalew, Cheng, Xia, Zhang, Yin, Wang, Wang, Dong, Zhang, Zhao, Qin, Zhang, Zhong, Zhen and Wang. 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: Tao Wang, College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin Province, China

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