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Alltech and Alimetrics collaborate on in vitro tool for estimating ruminal protein degradability

October 10, 2019

Scientists from Alltech and Alimetrics have collaborated on a study which compares the rumen degradability and effects on rumen fermentation of three protein sources: whey protein, soybean meal and yeast-derived microbial protein.

Meeting the protein requirements and improving nitrogen efficiency in cows under different physiological conditions can become more precise with the use of this additional  tool for diet formulation


[DUNBOYNE, Ireland and ESPOO, Finland] – An innovative laboratory fermentation method for assessing the ruminal breakdown of dietary protein ingredients has been created by Alltech and Alimetrics Research. The novel technique was developed to evaluate feed protein sources and involves measuring the proportion of certain amino acids that is converted to specific end products over 24 hours.

Scientists from Alltech and Alimetrics collaborated on the study, which has been published in the scientific journal Frontiers in Veterinary Science and compares the rumen degradability and effects on rumen fermentation of three protein sources: whey protein, soybean meal and yeast-derived microbial protein.

The assessment of protein degradation in the rumen of live animals has historically proven difficult, and although analysis of overall protein can be done, tracking the origin of protein from a specific feed component cannot be done with great certainty. In addition, ruminants have a low overall efficiency of nitrogen utilisation, with between 70– 95% of the nitrogen in diets excreted in dung and urine, according to the Food and Agriculture Organization of the United Nations. The use of this novel in vitro technique can help to overcome such challenges as it allows protein sources to be ranked according to their degradability by rumen bacteria.

“When it comes to comparing protein sources, we believe this tool is particularly useful when some known and commonly used benchmark products, such as soybean meal, are included in a study,” said Dr. Juha Apajalahti, managing director at Alimetrics.

Data from the study indicate that the yeast-derived microbial protein was the most resistant of all three protein sources to being degraded in the rumen, with less than 15% of the amino acids of interest being converted to end products measured. Additionally, the study showed that the level of the protein breakdown product, ammonia, from yeast-derived microbial protein was able to be taken up by the rumen bacteria, reducing excess rumen ammonia accumulation. Evaluation of other parameters demonstrated that the yeast-derived microbial protein was able to extensively stimulate rumen fermentation to the same extent as soybean meal.

These data not only suggest that this novel method is suitable for assessing ruminal breakdown of protein feeds, but also that yeast-derived microbial protein could potentially provide a more sustainable, and equally suitable, alternative to products such as soybean meal.     

“In terms of research methodology, this provides us with a robust model for screening products, both for fermentation effects and the ability to bypass protein through the rumen,” said Matthew Smith, vice president at Alltech. “The findings from this study clearly demonstrate the value of our yeast-derived microbial protein in stimulating rumen fermentation and volatile fatty acid and microbial biomass production. The tool itself is one we can use in our own in vitro fermentation model, Alltech IFM™, to aid future development.”

Click here to view the research article.