The rumen is truly a remarkable organ, one that allows ruminant livestock digest and upcycle human inedible food into high quality meat and milk. This extraordinary ability is thanks to a diverse population of micro-organisms that inhabit the rumen and are the true powerhouses of dairy, beef and lamb production. In just 1mLof rumen fluid you can find 100 billion bacteria, 10 million protozoa and 10,000 fungi, which equates to over a quadrillion (1,000,000,000,000,000) microbes per cow.
Each microbe has a unique function in the rumen, including specialists and generalists, and there is so much for us to learn yet. However in recent years, a new method known as 16sRNA sequencing is allowing scientists to identify microbes that would otherwise be invisible. These tiny microbes comprise over 90% of the rumen microbiome and offer promise in understanding how to better harness the microbiome to improve health, performance, sustainability and welfare. You could say we are potentially adding microbiology to the broad range of skills required to be a nutritionist or farmer.
In the everyday world of farming, we are seeing increasingly that 2024 forages have higher than normal NDF or fibre levels in first and second cuts. This is due to a lot of grass being carried over the winter in 2023 and delayed cutting in 2024, in addition to stressed grass plants moving into the reproductive phase quite quickly, even at lower covers.
The acres of land put down to maize is up, however reports show that quality is variable with limited cobb fill in many cases, likely leading to lower than desired starch levels.
These factors will pose a challenge for winter feeding, especially in terms of driving milk production from forage. Whilst no two farms or forages are the same, it will definitely pay to conduct regular forage analysis in order to determine the best diet for your herd.
Generally, higher levels of starch and sugar are will be needed (cereals and byproducts) to make the best use of lower digestibility forages. These should be fed alongside a supply of both rumen degradable and bypass protein to fully nutrient requirements and drive milk yield.
If we think back to the fact that the rumen microbes are responsible for the majority of feed digestion, while considering that forages will have a higher fibre content, we need to ensure that the rumen environment is in an optimal state to allow these microbes to thrive.
SUPPORTING THE RUMEN MICROBES
The rumen microbes need a few basic elements in order to function optimally:
- Consistency – Microbial populations adapt to changes in feed ingredients. Keeping the diet as consistent as possible helps to limit setbacks as microbes adjust to even small changes.
- Water – Essential for nutrient breakdown and ensuring microbes can move in the rumen, as well as other vital metabolic processes (keep in mind that a dairy cow is 60-70% water!)
- Balanced energy, protein NDF etc. – Ensure a balanced supply of essential nutrients for the microbes.
- Stable rumen pH – Facilitate the desirable microbes, particularly those that digest fibre.
- Low oxygen levels – Much like an anaerobic digester (AD) plant, rumen fermentation requires an oxygen-free environment.
Once the basics are covered, we can then fine tune the rumen microbiome to optimise the utilisation of this year’s diets. Beneficial microbes and the various fibre-digesting species are particularity sensitive to undesirable rumen conditions, like low pH and higher traces of oxygen. By removing oxygen and creating a more anaerobic rumen environment, Actisaf® has been repeatedly proven to enhance the digestibility of feed and forage.
We now know that differences in rumen microbial populations are responsible for over 60% of the variability between animals in terms of feed efficiency - recent research shows differences of 2.6kg DMI between dairy cows with the same level of milk production and more than 5kg DMI between beef cattle with the same live weight gain. Several groundbreaking pieces of research have also demonstrated that keystone species involved in lactate utilisation and fibre digestion are highly correlated with these more feed efficient animals.
THE ROLE OF ACTISAF
We know that Actisaf® is stimulating these same microbes and that the degree to which this occurs depends on the dose being fed.
By optimising the rumen environment and facilitating a shift in key microbial species, we have consistently seen significant benefits in feeding Actisaf® in a range of diets, from those that are prone to being highly fermentable and acidotic to those with high NDF levels.
In a study at the University of Nottingham, cows fed Actisaf® produced 2.8kg more energy corrected milk per head per day than cows fed control diets, despite having identical intakes. When we looked at how much of the diet was digested between the two groups we saw a significant improvement (4 points) in fibre digestion in the Actisaf® group. (See figures below)
MEASURING FIBRE DIGESTION
Recording and measuring the rate at which fibre is digested can traditionally be difficult and expensive to do at farm level. To help our customers and farmers do this more efficiently, Phileo by Lesaffre created Digescan™, a tool designed to practically demonstrate and monitor Actisaf’s impact on fibre digestibility, supported by an easy-to-use app for data capture and analysis.
Click here to learn more or contact your Phileo UK & Ireland representative.
Additional notes about the rumen microbes
The synergy and interaction between key rumen microorganisms, and their diverse enzymatic capabilities, allow for efficient degradation and utilisation of fibre in the ruminant diet, making them essential to growth, production, and overall health of ruminant livestock.
