Effects of Rumen-Undegradable Protein and Rumen-Protected Amino Acids on Small-Intestinal Microbiota in Sheep with Special Reference to Chinese Hu Breed
Pakistan Veterinary Journal, cilt.46, sa.7, ss.1636-1648, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Derleme
- Cilt numarası: 46 Sayı: 7
- Basım Tarihi: 2026
- Doi Numarası: 10.29261/pakvetj/2026.159
- Dergi Adı: Pakistan Veterinary Journal
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, CAB Abstracts, EMBASE, Directory of Open Access Journals, Academic Search Ultimate (EBSCO), Biomedical Reference Collection: Corporate Edition (EBSCO)
- Sayfa Sayıları: ss.1636-1648
- Anahtar Kelimeler: Hu sheep, Ileum, Jejunum, Nitrogen-use efficiency, Rumen undegradable protein
- Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
- Erciyes Üniversitesi Adresli: Evet
Özet
In ruminants, dietary crude protein does not directly determine the amino acids available to the small intestine because rumen-degradable protein (RDP) supports microbial synthesis, whereas rumen-undegradable protein (RUP) bypasses fermentation. Together, they define the metabolizable protein (MP) supply. The amino acid profile is delivered to the jejunum and ileum. Adjusting the RUP:RDP balance by using rumen-protected lysine (RP-Lys) and rumen-protected methionine (RP-Met) can improve growth and nitrogen-use efficiency. However, the response depends more on post-ruminal release and bioavailability on protection claims alone. Increasing evidence indicates that segment-specific luminal substrates and epithelial signaling are linked to microbial ecology. These effects include changes in mucosa-associated communities, metabolite networks, and barrier/immune markers. However, many studies rely on rumen or fecal measurements and cannot reliably infer mechanisms in the small intestine. This review synthesizes segment-level evidence relevant to Hu sheep. It also highlights how bioavailability and sampling compartment (digesta vs. mucosa) affect interpretation. In addition, it proposes a diet–substrate–epithelium–microbiota framework to guide future trials. Key gaps include limited causal designs, inconsistent reporting of protected amino acid release/availability, and insufficient integration of nitrogen partitioning with intestinal endpoints. Addressing these gaps will strengthen gut-resilient nutritional strategies in Hu sheep production systems.