Your reading list

Good bacteria: they’re found in yogurt and silage

Researchers look at using the next generation of inoculants to help livestock producers turn silage into a probiotic

FRIEDENSFELD, Man. — With probiotics, it’s hard to separate hype from reality.

Supporters claim that probiotics, products loaded with beneficial bacteria, are a cure-all for a long list of diseases.

Others aren’t convinced. They believe that probiotics don’t stand up to scientific scrutiny.

Nonetheless, it’s becoming common for dairy farmers and other producers to include a probiotic in their animals’ diets.

Many farmers believe they improve herd health, help cows resist infection and may increase milk production.

Given the interest in probiotics, scientists are looking at different ways to add beneficial micro-organisms to a cow’s diet.

One possible way could come from inoculants added to silage. Inoculants are live bacteria introduced into silage, which help lower the pH, prevent the growth of harmful micro-organisms and improve forage digestibility.

The next generation of silage inoculants, now in development, will do all that and more, said Tim McAllister, a ruminant nutrition and microbiology expert with Agriculture Canada in Lethbridge.

“Plus, the silage will act as a probiotic. Rather than you buying probiotics and putting it into the animals every day, the probiotic will be naturally in the silage,” said McAllister, who spoke at Manitoba Hay Day, a workshop held in Friedensfeld, Man., in June.

McAllister travelled to southeastern Manitoba to talk about the latest research and best practices for making silage.

One piece of research he’s working on is an attempt to understand why inoculants sometimes work for silage and sometimes don’t.

“The use of inoculants allows you to add in bacteria that are known to enhance the ensiling process,” he said.

“We use those inoculants as an insurance factor because the natural population (of micro-organisms) on the plant is quite unpredictable….

“You can’t … look at your forage and say it has all good bacteria and I don’t need an inoculant.”

The inoculants may add beneficial bacteria but they don’t always function as expected because it depends on the forage.

McAllister and his colleagues are hoping to change that. They are extracting DNA from forage samples to understand how inoculants react to different silage conditions.

“We sequence that DNA and identify all the bacteria, yeasts and moulds associated with that,” McAllister said. “Then we can tell this microbial population and … this inoculant, it worked really well. (Or) this microbial population, we added the inoculant and it didn’t work so well.”

With such knowledge, it may be possible to recognize the bacterial communities on forage and adjust the inoculant so it works every time.

Besides inoculants, McAllister shared his thoughts on how to make high quality silage.

A producer at the meeting asked about barley varieties and which varieties produce the best silage. McAllister answered that variety does matter, but the impact is minimal.

“Other factors like time of harvest and how you ensile it, all of those things have a much greater impact on the quality of the (silage) than the variety does.”

McAllister showed a slide, breaking down the key factors that influence silage quality:

  • Crop maturity determines 60 percent of quality.
  • Harvest and storage accounts for 15 percent.
  • Weather makes up 10 percent.
  • Soil fertility determines five percent.
  • Crop variety makes up three percent of silage quality.

“By far the most important thing is the timing part,” he said. “Pay attention to the basics.”

Phil Bourque of Dairy Smart Nutrition, in an online video, echoed McAllister’s point that crop maturity is critical for barley silage.

“It’s (about) waiting and waiting for that right time,” he said.

“When we squeeze (a kernel) and it’s at the right stage, it’s going to be getting to a late, soft-dough stage. There will be no milk…. The head will be yellow.”

The window of opportunity to get it right is narrow in Western Canada.

McAllister estimated that barley is in the proper stage of maturity for about a week.

About the author


Stories from our other publications