Read the current Progressive Forage digital edition
advertisement

COUNTERPOINT: In response to 'Inoculants: Insurance or strategy?'

Scott Dennis Published on 28 September 2012
 

counterpointI feel the need to respond to the recent article entitled, “Inoculants: Insurance or strategy?” (Editor’s note: This article appeared in the July 1st, 2012 issue of Progressive Forage Grower Click here to read).

I will preface my response by stating that as a trained microbiologist, I have spent 30 years with Pioneer Hi-Bred researching the lactic acid bacteria involved in silage fermentation.

The article is correct that dry matter losses occur during the “front-end” fermentation and during “back-end” feedout.

Research has shown that of the total fermentation losses, about 40 percent typically occur during the initial “front-end” pH decline, with about 60 percent occurring during the feedout phase. This is accentuated by the huge surface area exposed on many large bunker and pile faces.

That said, focusing solely on “front-end” losses does not seem the most effective strategy to reducing total dry matter loss.

It is apparent from extensive research with thermal imaging that good silo management alone is not sufficient to guarantee reduced losses or the heating initiated by yeast populations.

Preventing aerobic feedout losses has been the significant contribution of silage inoculants containing L. buchneri, proven in university trials.

The article further states that L. buchneri “require a high pH to grow and are inhibited by low silage pH.” This statement, as it pertains to Pioneer strains of L. buchneri strains, is completely false.

In fact, most L. buchneri thrive at near-terminal silage pH and are actually much more acid-tolerant than homofermentative lactic acid bacteria (L. plantarum, E. faecium, L. casei), found in many inoculants to promote faster fermentation.

Two recently published studies by Dr. McAllister at the Agriculture and Agri-Food Canada, Lethbridge Research Centre demonstrate that strains of L. buchneri can indeed function at low silage pH (references available upon request).

Finally, the article asserts that the silage producer must make a choice between selecting an inoculant that promotes decreased dry matter losses during the “front-end” of the fermentation or during the “back-end,” feedout phase.

The studies cited above are proof that the “combination” of homofermentative lactic acid bacteria and L. buchneri is an effective silage management strategy to improve both fermentation and aerobic stability.

—Scott Dennis, Ph.D., Microbiologist and Technical Training Manager, DuPont Pioneer

 

LATEST BLOG

LATEST NEWS