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BMP testingGrain, bran, feed and fodder

Rabbit and rodent feed pellets — BMP: 12 studies, weighted mean 330 m³ CH₄/t VS

Pelleted feed for rabbits and rodents is a test material from an interlaboratory BMP programme: a pellet of plants and cereals. The compilation contains curves measured at many laboratories.

CH₄ ≈ 52 % (estimate)

Published Updated 3 min readFeedstockData Editorial Team

Illustration: FeedstockData (AI, Google Gemini)

Weighted mean
330m³ CH₄/t VS
Range
231–381m³ CH₄/t VS
Records
12studies
Publications
2sources
Temperatures
35 °Cof the test

Methane in biogas

Medium methane content · ≈ 5.2 kWh/m³ of biogas

estimate from the substrate type The collected studies contain no measurement. The interval follows from the approximate composition (carbohydrate-dominated (no protein or fat characteristics)) and the yields of compound groups according to FNR.

How we calculate it and what the zones mean

Rating for biogas plants

not rated — editorial rating for biogas plants

Not rated: no dry matter or volatile solids in the data. We calculate the rating when the dry matter and volatile solids of the material are known.

Editorial rating per the methodology

Add to the co-digestion calculator CSV data

BMP curves from 12 studies

Weighted mean Individual records

BMP curves: Rabbit and rodent feed pelletsCumulative methane production over time for 12 records and the weighted mean of 330 m³ CH₄/t VS. 1 of the curves are model curves (first-order kinetics).0100200300400500051015202530time [d]m³ CH₄/t VSHafner et al. (2026) · lab. E18: 317 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. E21: 321 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. E08: 323 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. E27: 328 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. R03: 332 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. R04: 333 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. E19: 334 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. R05: 347 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. R02: 347 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. R06: 368 m³ CH₄/t VS (measurement)Hafner et al. (2026) · lab. E13: 381 m³ CH₄/t VS (measurement)Kouas et al. (2017): 231 m³ CH₄/t VS (model curve)mean330

Dashed lines are a model curve (first-order kinetics, B(t) = B₀·(1 − e−kt)); the end point comes from the publication. Solid lines are measurements (11).

Cumulative methane production over the test [m³ CH₄/t VS]. The thick line is the weighted mean of all records (330); dots mark the end values given in the publications. Point at the chart to read values; click a legend item to hide or show a record.

Records and sources

Download CSV
SourceBMP
m³ CH₄/t VS		TemperatureSampleCurve
Hafner et al. (2026) · lab. E18 DOI317— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. E21 DOI321— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. E08 DOI323— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. E27 DOI328— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. R03 DOI332— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. R04 DOI333— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. E19 DOI334— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. R05 DOI347— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. R02 DOI347— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. R06 DOI368— · mesophilicRabbit feedmeasurement (31 pts)
Hafner et al. (2026) · lab. E13 DOI381— · mesophilicRabbit feedmeasurement (31 pts)
Kouas et al. (2017) DOI23135 °C · mesophilicdry food pelletsend point (model curve)
Weighted mean330arithmetic mean 330, SD 37

Process properties

  • easily degradable
  • fibrous
  • variable composition
  • physical contaminants
  • editorial classification

Low confidence: the description is based on general characteristics of the substrate group, not on studies of this material. Treat it as a hint to be verified.

Advantages

  • Methane potential in the database: weighted mean 330 m³ CH₄/t VS (median 332; range 231–381; 12 records from 2 sources).
  • The data come from the interlaboratory BMP study (Hafner 2026) and from the Kouas 2017 test.

Drawbacks and risks

  • Spread of results in the database: standard deviation 37 at a mean of 330 m³ CH₄/t VS (12 records from 2 sources).

Co-digestion — what to combine it with, what to watch out for

Dosing

No source-based dose limits.

Practical requirements

  • Shred: shredding increases the surface available for degradation and speeds it up, but does not necessarily raise the final gas yield (FNR 2010, Ch. 3 “Triturado”).

Sources of the process data

  1. Kouas, M.; Torrijos, M.; Sousbie, P.; Steyer, J.P.; Sayadi, S.; Harmand, J. (2017) Robust assessment of both biochemical methane potential and degradation kinetics of solid residues in successive batches. Waste Management 70, 59–70
  2. Weiland, P. (2010) Biogas production: current state and perspectives. Applied Microbiology and Biotechnology
  3. Hafner, S.D.; Leca, E.; Sambusiti, C.; Astals, S.; Azam, O.; Koch, K.; Liu, J.; Møller, H.B.; Nistor, M.; Olaya-Rincon, M.; Peyrelasse, C.; Ward, A.J.; Zennaro, B.; Monlau, F. (2026) Reliable biochemical methane potential testing: insights and recommendations from global interlaboratory study. Bioresource Technology 446, 134136
  4. Hendriks, A.T.W.M.; Zeeman, G. (2009) Pretreatments to enhance the digestibility of lignocellulosic biomass. Bioresource Technology
  5. FNR (2010). Guía sobre el Biogás – Desde la producción hasta el uso (hiszp. wydanie „Leitfaden Biogas”, GIZ 2013)

The co-digestion calculator will assess a specific mixture containing this substrate.

What it is and where it comes from

Pelleted feed for rabbits and rodents is a commercial product made of ground plants (lucerne, grasses, cereals, additives), pressed into pellets. It is available in shops and has a relatively constant composition, which is why it was used in the interlaboratory BMP programme as a test material. The compilation contains several records: eleven from the 2026 programme, with curves measured at many laboratories, and one for pelleted guinea pig feed from another study.

Properties relevant to digestion

The pellet contains a lot of plant fibre from lucerne and grasses, alongside starch from cereals and protein. Degradation is therefore faster than for straw, but slower than for pure starch. The pellet disintegrates after wetting, but its structure and compaction affect the initial rate of degradation. A high protein content favours ammonia release at higher doses. It is not a biogas plant substrate, but a material that shows well the behaviour of a plant mixture with a composition typical of feeds.

How to read the spread of results

Several records from the 2026 programme are results for a single sample from many laboratories, so the spread indicates the effect of methodology: inoculum, substrate-to-inoculum ratio, size reduction, gas measurement system and test length. The result on day 30 of the test was adopted. An additional record comes from another study and concerns pellets for guinea pigs, that is, a similar but not identical product, and was carried out at 35 °C. The difference therefore does not stem from measurement uncertainty, but from a different material.

In biogas plant practice

Pelleted feed is not a typical biogas plant substrate, but it may appear as an expired or rejected batch. The value of the compilation for practice lies in the fact that data from many laboratories show the real repeatability of the BMP method. It is good to choose a laboratory that takes part in comparative studies and to require a full description of the test conditions. When assessing your own batch of pellets, size reduction and the inoculum are of key importance for the result. As with other materials from the programme, it is worth paying attention to the course of the curve and not only the final result. This makes it possible to assess whether the laboratory prepared the sample correctly and whether the inoculum was active throughout the test period.

Methodology in brief

BMP is the amount of methane obtained from volatile solids (VS) in a batch test, given in m³ CH₄ per tonne of VS (numerically the same as NmL CH₄/g VS in the publications) and converted to normal conditions (0 °C, 101.325 kPa). The weighted mean gives each publication a total weight of 1, split equally between its results for the substrate — a paper testing twenty varieties does not outweigh a paper with a single sample. In inter-laboratory programmes the unit is the laboratory (total weight 1), and within it the weight of a test grows with the number of bottles (replicates). Results after pretreatment (e.g. thermal, chemical, enzymatic) are shown separately and are not included in the mean.

Solid lines are curves measured in the tests. Where a publication gives only the final result, we draw a first-order kinetic model, B(t) = B₀·(1 − e−kt): only the end point comes from the publication, and the shape of the curve serves purely as visualisation — do not read the production on a particular day from it. For this substrate k = 0.257 d−1 was assumed (median of rate constants k reported in the sources and/or fitted to the mean measured curves).

The statistics describe the spread of published results — a descriptive compilation, not a meta-analysis or a guarantee of plant yield.

Full methodology and correction policy

Bibliography

  1. Hafner, S.D.; Leca, E.; Sambusiti, C.; Astals, S.; Azam, O.; Koch, K.; Liu, J.; Møller, H.B.; Nistor, M.; Olaya-Rincon, M.; Peyrelasse, C.; Ward, A.J.; Zennaro, B.; Monlau, F. (2026). Reliable biochemical methane potential testing: insights and recommendations from global interlaboratory study. Bioresource Technology 446, 134136. DOI: 10.1016/j.biortech.2026.134136 DOI
  2. Kouas, M.; Torrijos, M.; Sousbie, P.; Steyer, J.P.; Sayadi, S.; Harmand, J. (2017). Robust assessment of both biochemical methane potential and degradation kinetics of solid residues in successive batches. Waste Management 70, 59–70. DOI: 10.1016/j.wasman.2017.09.001 DOI

All sources of the site: bibliography.

Other substrates in the group “Grain, bran, feed and fodder”