Fibre – made up of cellulose, hemicellulose and lignin – is a core component of forages and offers a key source of energy in ruminant diets, potentially providing energy levels similar to starch and sugar.
But accessing this energy requires fibre digestion by rumen microbes, and as such, the efficiency of this digestion has a significant bearing on the nutritional potential of forages when fed.
Taking steps to improve fibre digestion within the rumen should therefore always be a key consideration within feeding regimes. This will improve the utilisation of the available forage, as well as the overall diet, supporting increased production – both milk yield and quality – alongside more fertile, healthier cows.
For example, for every 5% increase in NDF digestibility a cow will increase their Dry Matter Intake (DMI) by 630g/day resulting in a 0.9kg increase in fat corrected milk.
Winter feeding considerations
Grass silage quality is a mixed bag this year and it’s important to take into consideration your particular scenario when looking to maximise the value of the forage available.High dry matter (DM) silage: A dry ration is comparable to Weetabix without the milk, and steps will need to be taken to improve forage palatability to ensure adequate feed intake. Sorting can also be an issue in high DM total mixed rations (TMR’s), increasing the risk of digestive upsets and acidosis which can severely hamper rumen function and therefore feed efficiency. Adding water to the ration can be a simple, yet effective option.
It’s also worth bearing in mind that drier forages are typically more difficult to compact, increasing the risk of heating and mould growth on opening.
Low DM silage: In the case of wet silages, cows need to eat a higher total volume (fresh weight) to receive the same DM and this can result in lower DMI due to the bulk fill of water from the silage. Wet silage tends to have an increased acid load in the rumen due to higher lactic acid concentrations in the silage. Ideally wet silages should be balanced with drier silages such as wholecrop cereal silage when available.
Benefits of including a live yeast
There are several practical ways to optimise fibre digestion, including feeding more often, pushing up regularly, offering a cool, stable and palatable ration, and avoiding overcrowding at the feed face to maximise eating and crucially lying time.Feeding a live yeast however can also offer a very good return on investment (ROI), due to its positive impact on feed digestion, particularly of the fibre fraction of the diet. The rumen specific live yeast, Saccharomyces cerevisiae CNCM I-1077, known commercially as Levucell SC, can stimulate the growth and activity of the fibrolytic bacteria and fungi. In-vivo trials with more than 200 different forage samples show that Levucell SC significantly increases forage NDF degradability in the rumen with a greater effect seen on lower NDFd forage.
It’s important to note that not all live yeasts are equal and each strain will have distinct effects on different microbial species. Levucell SC has been specifically developed for ruminants to yield the greatest benefits and is backed by extensive trial work.
When fed, trial work during lactation shows that Levucell SC delivers a significant and consistent improvement in performance, delivering on average a 1.1kg/day* uplift in milk yield from a 3% improvement in feed efficiency. Under rumen challenged conditions the average milk yield response can increase to 2kg/day**.
The benefits of feeding Levucell SC on feed efficiency can also be gauged by sieving the manure, with a notable reduction in the volume of material captured within the top sieve in all cow groups receiving the live yeast.
