Supplementation of probiotic fibrolytic enzymes to improve the utilisation of fibre by ruminants


The potency of exogenous cellulolytic enzymes as feed additive of ruminant has also been examined since late 1950s but it did not show any significance in improvement of the efficiency of feed utilization. The failure to obtain a significant improvement of fibre digestion in vivo should not be so surprising. Since the microbial consortium in the rumen is perfectly evolved in effective degradation of cellulose and hemicellulose, any additional enzymes must be super active and resistant to microbial and digestive proteolytic enzymes. In the recent years, biotechnologies have been greatly developed and active fibrolytic enzymes have been industrially produced. Powerfulness of the newly exploited exogenous cellulase and xylanase encourages one to apply them to improve utilization of fibrous feeds in ruminants.


Dr Alex Chaves

Research Location

Sydney School of Veterinary Science

Program Type



In practice, when enzymes are to be used as feed additives, they should be resistant to the proteolytic attack from rumen microorganisms and enzymes in the digestive tract and acidic condition of the stomach. On the other hand, the addition of enzyme should not significantly affect synthesis of endogenous enzymes, otherwise the supplementation may not get net profit. Therefore, this project has a goal to determine stability of the enzymes in the rumen and the stomach, and to determine the effect of supplementary enzymes on synthesis of endogenous fibrolytic enzymes in the rumen.

The major objectives of this research are to:

1. Determine whether supplementation of the fibrolytic enzymes improves fibre digestibility and the efficiency of feed utilization by ruminants;

2. Determine whether supplementation of the fibrolytic enzymes affects ruminal fermentation and depresses methane production;

3. Determine whether supplementation of the enzymes affects site of digestion and bacterial efficiency, and

4. Determine the stability of the exogenous enzymes in the digestive tract and the effect of enzyme additions on synthesis of endogenous fibrolytic enzymes by rumen cellulytic bacteria.

Additional Information

- Opportunity to travel overseas (Canada) and work with a multidisciplinary team. Minimum 6 months.

- Research facilities provided for this project are breath-taking. Lethbridge Research Centre is the excellence beef research centre in Canada and it is located 1.5h from the Rocky Mountains.

- Opportunity available for Honours and PhD students.

- Techniques and research approaches: in vitro, in situ, and in vivo studies.

- Funding for the actual research is available. However, a scholarship is not included so students who already have funding/or are applying for an APA have a greater chance with this opportunity.

- Eligibility criteria: discussed on individual basis.

Additional supervisors include:

Drs Tim McAllister and Sam Ohene-Adjei - Agriculture and Agri-Food Canada, Lethbridge, AB, Canada

Dr Kim Stanford - Alberta Agriculture and Rural Development, Lethbridge, AB, Canada

Drs Alex Hristov and Jud Heinrichs - Penn State University, USA.

Students involved in this project:

PhD Candidate: Gustavo Lascano - Penn State University, USA.

Results generated from this research will be disseminated to interested parties through peer-review scientific publications.

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Ruminant, nutrition, fibre, digestion, methane, microbial, protein, synthesis, in vitro, in vivo, in situ, overseas travel; international collaboration; animal science; ruminant nutrition.

Opportunity ID

The opportunity ID for this research opportunity is: 604

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