Comparative impact of fungal and microbial proteases on the rumen and fecal microbiota composition and nutrient digestibility in Kazakh White Head bulls

Vet World Vol.18 November-2025 Article - 18

Research Article

Veterinary World, 18(11): 3536-3544

https://doi.org/10.14202/vetworld.2025.3536-3544

Viktoriya Vladimirovna Grechkina^1,2

, Elena Vladimirovna Sheida^3,4

, Olga Vilorievna Kvan^3,4

, and Artem Vladimirovich Bykov⁵

1. Federal Scientific Center of Biological Systems and Agrotechnologies of the Russian Academy of Sciences, ul. 9 January, 29, Orenburg, 460000, Russian Federation.

2. Department of Non-Communicable Animal Diseases, Orenburg State Agrarian University, ul. Chelyuskintsev, 18, Orenburg, 460014, Russian Federation.

3. Department of Food Biotechnology, FSBEI HE “Orenburg State University,” 460018, Orenburg, Povedy avenue, 13, Russia.

4. Department of Feeding and Feed Technology Named after S.G. Leushin, Federal Scientific Center for Biological Systems and Agro-Technologies of the Russian Academy of Sciences, 29 9th January Str., Orenburg, 460000, Russia.

5. Department of Food Biotechnology, Doctor of Biological Sciences, Associate Professor, Federal State Budgetary Educational Institution of Higher Education “Orenburg State University”460018, Orenburg, Povedy avenue, 13, Russia.

Background and Aim: Proteases are key enzymes that hydrolyze peptide bonds enhancing the utilization of feed protein, improving nutrient efficiency, and reducing the need for costly protein ingredients. Despite their growing use in animal nutrition, comparative studies between fungal and microbial proteases in ruminants remain scarce. This study aimed to evaluate the influence of fungal and microbial proteases (25 U/g each) on the microbial composition of rumen fluid and feces, and on the chemical composition of digestive contents in Kazakh White Head bulls.

Materials and Methods: Twenty bulls (14–15 months old; 310–320 kg) fitted with rumen fistulas were divided into three groups: a control group and two treatment groups, each receiving a basal diet supplemented with either fungal or microbial protease. Rumen fluid and fecal samples were analyzed for taxonomic profiles using next-generation sequencing (MiSeq, Illumina) of the 16S ribosomal RNA V3–V4 region. Chemical composition (dry matter [DM], crude protein [CP], crude fat [CF], crude fiber, and ash) was determined according to GOST mass fraction of DM 31640, mass fraction of CP 13496.4, mass fraction of CF 13496.15, mass fraction of crude fiber 31675, and mass fraction of crude ash 26226 standards. Statistical analysis was performed using the Mann–Whitney U-test (p ≤ 0.05).

Results: Microbial protease supplementation increased the abundance of beneficial phyla Bacillota (70.1%) and Bacteroidota (19.5%) in rumen fluid, with a corresponding rise in DM (+6.3%), CF (+9.4%), and CP (+7.9%) relative to control. In feces, Bacillota (70.7%) and Bacteroidota (15.5%) predominated. No opportunistic pathogens (e.g., Pseudomonas and Sutterella) were detected in the microbial protease group, indicating improved microbial balance and intestinal protection. Fungal protease exerted milder effects, with modest increases in nutrient fractions.

Conclusion: Microbial protease was more effective than fungal protease in optimizing rumen microbiota and enhancing nutrient digestibility in bulls. Its use may support environmentally sustainable livestock production by reducing nitrogen excretion and dependence on high-protein feed ingredients. These findings provide a scientific basis for breed-adapted enzymatic feeding strategies in ruminants.

Keywords: cattle, fungal protease, microbial protease, next-generation sequencing, nutrient digestibility, rumen microbiota.

How to cite this article: Grechkina VV, Sheida EV, Kvan OV, and Bykov AV (2025) Comparative impact of fungal and microbial proteases on the rumen and fecal microbiota composition and nutrient digestibility in Kazakh White Head bulls, Veterinary World, 18(11): 3536–3544.

Received: 01-07-2025 Accepted: 23-10-2025 Published online: 27-11-2025

Corresponding author: Olga Vilorievna Kvan E-mail: kwan111@yandex.ru

DOI: 10.14202/vetworld.2025.3536-3544

Copyright: Grechkina, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.