Technology: Hilgardii: New name in silage inoculants

A new strain of bacteria found in maize silage in South America will be put to work next year improving millions of tonnes of silage around the world.
Technology: Hilgardii: New name in silage inoculants

Biotal has announced the arrival of Lactobacillus Hilgardii, a significant technological advance for the UK company which has been at the forefront of research into effective preservation and utilisation of forages for over 25 years.

Their discovery of the L Buchnerii bacteria in the 1980s delivered a new generation of silage inoculants to reduce waste and improve feed quality, and was a big factor in the acquisition of Biotal in 2001 by Lallemand Animal Nutrition, a primary worldwide manufacturer and supplier of inoculants which have bacteria and enzymes for rapid initial silage acidification (preservation), stability and palatability.

L Buchnerii 40788 has become the world’s most independently researched inoculant bacteria, with more than 40 peer-reviewed papers.

The story of its likely successor, L Hilgardii, began when experts at Lavras University in Brazil observed that local maize silages were remarkably stable.

As part of the ongoing global search for effective silage inoculants, about 100 bacteria from the Brazilian silages were analysed, and L Hilgardii has emerged with immense promise.

Biotal’s L Buchnerii patents expired last year, but they are now confident they have an active ingredient to follow in its footsteps, after positive results from exhaustive trials around the world of L Hilgardii as a silage preservative.

The trials showed impressive results for aerobic stability in silages, meaning that a combination of L Hilgardii and L Buchnerii in an inoculant will significantly reduce wastage and secondary fermentation.

An Irish trial of the Hilgardii and Buchnerii combination inoculant, in a very wet, 18% dry matter maize silage, showed only 4% dry matter loss at 15 days after ensiling.

“Silage waste is still a huge drain on farmer profits, so we have worked to identify which bacterial strain is the most effective at reducing waste,” said Lallemand’s Irish business manager, Bryan Buckley.

“Treating forages with strains of bacteria specifically identified to drive a faster and more efficient fermentation can have a big impact on feed costs, improving margins and promoting healthier cows.”

Having completed two stages of EU regulations, the product will go to market next year, confirmed Biotal technical manager John Bright last week at Biotal’s Malvern, Worcestershire, headquarters, where those attending the Biotal UK spring advisory tour included staff from Specialist Nutrition, which distributes Biotal silage additives in Ireland.

Further trials of the Hilgardii and Buchnerii combination inoculant will look at its effects on silage quality.

The advisory tour included an insight into how the inoculant manufacturer grows billions of bacteria for an inoculant silage additive.

“We sell bugs”, said production director Tim Nelson, explaining how a selected species and strain of bacteria is preserved in liquid nitrogen to preserve its genetic integrity, and a sample is inoculated into sterile media in fermenters to start bacterial growth.

He said it takes seven years to identify a bacterium, go through trials in thousands of tonnes of silage, and the EU regulatory process, before multiplying the bacteria for inclusion in inoculants which go on to farms with a guaranteed 18-24 month shelf life.

It is a unique manufacture process, because the material is a living organism. At one stage of the process, the acid production by the bacteria — which make them an effective silage preservative — has to be countered during fermentation by adding 1,000 litres of 37% caustic soda to each 14,000-litre fermenting vessel.

Growth is monitored so the bacteria can be harvested at peak numbers. Harvesting involves cooling to slow down and stop fermentation, and centrifuging the fermentation product to produce a 35% solution of bacteria.

Then, secret formula cryoprotectors are used to protect bacterial cells during freeze drying (drying by heat would damage them), as the bacteria are stabilised to a guaranteed shelf life.

For this process, Biotal uses £1m (€1.18m) freeze driers imported from New Zealand.

The pure bacteria are then blended and formulated into the products farmers use.

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