Use of silage additive can greatly increase the efficiency of the fermentation in the clamp, minimising waste and maximising the nutritional value of the preserved forage.
“Additives dominate the fermentation process by ‘flooding’ the silage pit with highly efficient strains of bacteria,” says Dr Simon Pope, Wynnstay crop protection manager.
“At the most basic level, bacteria ferment sugar in the grass to produce lactic acid, and it’s this acid which creates well preserved silage,” he adds.
“The lactic acid producing bacteria occur naturally in the field, and are already present on the grass when it is chopped.”
However, he explains that like any naturally occurring population, there is a diverse range in the types of bacteria which are present in the field.
“Some are extremely efficient at converting sugar into lactic acid, while some are at the opposite end of the spectrum and are quite wasteful.
“The goal is to produce a rapid and efficient fermentation, to produce stable, well preserved silage, while losing as little of the feed value as possible.
“The average efficiency of fermentation in untreated grass silage is around 55%. This efficiency can be greatly increased by adding an appropriate additive, which contains strains of bacteria selected for their ability to produce as much lactic acid as possible, by ‘burning’ as little sugar as possible.
“Therefore, more of the nutrients remain in the preserved forage and the result is a silage with a significantly higher feed value.”
Dr Pope explains that protein breakdown also occurs during the ensiling process, but a rapid and efficient fermentation minimises the amount of protein lost, and again the feed value of the silage is maintained at a higher level.
“Alongside the lactic acid bacteria, spoilage organisms also occur naturally in the field. When allowed to multiply in the clamp, these ‘bad’ bugs cause deterioration in silage quality and increase dry matter (DM) losses.
“The use of silage additive products means the inefficient strains and the spoilage organisms can’t compete, as they don’t get the chance to multiply. The result is higher feed value silage with lower DM losses,” he adds.
They are often defined by the number of colony forming units (CFU) applied per gramme of forage (CFU/g), with the majority of products on the market offering from 100,000 CFU/g up to 1 million CFU/g.
“Although this appears a large number, there is now the option to apply double the amount.
“Wynnstay’s grass silage additive, Wynnstay Dominator, applies 2 million CFU/g, ‘flooding’ the silage with highly efficient strains of bacteria. Where DM is at 30% or higher, Wynnstay Hi-Dri is recommended. It not only contains 2 million CFU/g, but has the added benefit of including a specific yeast and mould inhibitor, designed to further improve aerobic stability.
“A lot of time, effort, and money goes into the whole process of ensiling the grass crop to create a well preserved high feed value forage. Therefore, additive usage should be considered as an essential management tool.”