Grass silage inoculant boosts fibre digestibility and milk yields

Malvern, United Kingdom – Using an inoculant on grass silage can significantly increase fibre digestibility and boost milk yields by more than a litre a day, according to results from a ground-breaking trial.

The study, carried out by the Miner Institute in New York State, assessed the impact of a Lallemand Animal Nutrition Magniva Platinum grass silage inoculant on Neutral Detergent Fibre digestibility (NDFd)¹.

Lientjie Colahan, forage technical support at Lallemand, says the results highlight how the use of a crop- and condition-specific inoculant on grass silage can deliver more milk in the tank for farmers.

“The importance of NDFd in grass silage cannot be underestimated, as previous research has shown a 1% improvement in NDFd can lead to a 0.17kg increase in Dry Matter Intake (DMI) and an additional 0.23kg of milk production²,” adds Mrs Colahan.

“The results from this trial show a significant improvement in NDFd from using a Magniva Platinum inoculant – highlighting how an inoculant is not only important for preserving silage quality, but also for improving fibre digestibility which can positively impact milk yields.”

She says the Miner trial measured NDFd in two silage crops containing a mix of alfalfa and grasses, which were ensiled for 160 days – one was treated with Magniva Platinum and the other received no inoculant treatment.

“The improvement was most noticeable after 48 hours of ruminal digestion with a 5.4% increase in NDFd recorded in the treated crop,” says Ms Colahan.

“Based on the Oba & Allen (1999) research, this result can lead to an increase in DMI of 0.92kg/cow/day, and increased milk production of 1.23kg/cow/day.”

Mrs Colahan says the improvements in digestibility demonstrated in the Miner trial are down to highly specific enzymes present in the inoculant.

“Improving diet digestibility by feeding enzymes is commonplace in monogastric diets, but is not widely adopted for ruminants due to the notion that the rumen microbes would break down the enzymes,” she explains.

However, recent studies for enzyme application at ensiling have proven that a pre-digestion occurring outside of the rumen can improve animal performance.

"Very few inoculants on the market contain enzymes, but these can help break down the fibre components of grass silage, particularly cellulose and hemicellulose," Mrs Colahan explains.

"These structural fibres – alongside lignin – are interwoven like a rope. Specific enzymes in the inoculant help to unwind those strands of fibre, breaking down bonds in cellulose and hemicellulose. This releases simple sugars that beneficial bacteria can utilise to enhance fermentation and improve silage digestibility.

“The enzymes naturally stop working once the optimum pH is reached in the silage, to prevent excessive fibre breakdown during storage.”

“The results from the Miner trial show the production benefits that can be achieved by treating grass silage with a condition-specific inoculant,” she adds.

“It not only helps preserve silage quality and stability but also helps improve dry matter intakes and milk yields – meaning producers will see a worthwhile return on investment if they use the right inoculant when making grass silage.”

Full details of the Magniva inoculants range are available here.

References

1. Forage Centre of Excellence, Miner Institute (unpublished)
2. Oba, M., and M. S. Allen. "Evaluation of the importance of the digestibility of neutral detergent fiber from forage: effects on dry matter intake and milk yield of dairy cows." Journal of dairy science 82.3 (1999): 589-596.