By Tim Kalinowski
Grazing and seeding systems come and go in Canadian agriculture on foraged land, says Dr. Alan Iwaasa, a grazing management and ruminant nutrition scientist with Agriculture and Agri-Food Canada stationed at the Swift Current Research and Development Centre, but the fundamentals tend to remain the same: Conservation of forage pastures to sustain cattle production over multiple generations and healthy feed to keep animals growing and strong.
“Producers have always been interested, to some degree, in maintaining their pastures and grazing pastures efficiently in a sustainable manner,” says Iwaasa. “As a result of that, by having good grazing management, and by looking at how the productivity of the pasture is sustained over many years, that they were actually encouraging a healthy, natural state within their pastures.”
Iwaasa says, however, the picture of how it is all supposed to work together does change as agricultural practices improve, technology evolves and the greater complexities of forage lands become better understood.
The monoculture seeding of the past, in this regard, he says, has given way to a more complimentary sense of how different grasses, native prairies species and legumes work together to improve total animal and pasture health.
Alfalfa’s benefits, for example, are already well-understood, says Iwaasa, but other prairie legumes like sainfoin and purple prairie clover bring a whole different set of lesser understood benefits to the table.
“The major advantage of looking at sainfoin versus alfalfa, even though alfalfa is a really good forage with good production in this (semi-arid) area, is the sainfoin is non-bloating,” says Iwaasa.
The other benefit of sainfoin, and to an even greater extent purple prairie clover, is the levels of condensed tannins found within. Iwaasa explains.
“The condensed tannin is a natural product within the plant that provides benefits to grazing animals against insects, against disease, as long as it is not to the point where it causes some inhibition to the animals not grazing or eating it.
“There is fine line between having too much tannins versus having just the right amount, not only in having some protection, but can also be utilized, grazed and consumed by the animal.
“In the case of sainfoin, it does have these condensed tannins that can bind with protein, and this is what actually prevents it from causing any bloating to occur. When condensed tannins combine with the protein, in this case, it can also bring additional nutrition benefits by bypassing the rumen breakdown.
“But what we found very interesting is in the case of the purple prairie clover is it has one of the highest cases of condensed tannins, considerably higher than sainfoin, but it does not seem to inhibit the animal from grazing it.”
Iwaasa says groundbreaking research is still being done on purple prairie clover, but the trial results have been intriguing and promising.
“We have found as far as some of the work we have done already that prairie clovers, in particular the purple clover, we have found it not only has had some advantages as far as extending the grazing season, it does fixate nitrogen. It’s more of a warm season legume, which has most of it growth into that July and August period.”
He says research done by his colleagues at the Lethbridge Research Station shows purple prairie clover also helps the animal consuming it shed less deadly E-coli bacteria in their dung.
“So there is not only a production benefit,” he confirms, “but an environmental health and human health benefit.”
Iwaasa expects ideas surrounding forage health and sustainability will continue to evolve going forward, and he and his colleagues are hoping their research will plant the seeds of those future forage systems— the amazing dimensions of which he can but glimpse at the moment.
“I believe in a complimentary grazing system where sometimes there might be the need to have native pastures we can utilize at certain times of the year, perhaps more in the fall period of time, and then rely on cool season grasses for some of our spring grazing or early summer,” he says by way of example.
“We have a lot of different cool season species that tend to go to full maturity early to mid-summer, and then you have that summer slump season around August or early September.
“As a result of that, we have to look at what are some of these different legumes or grasses extending into that summer slump period.”
The potential for greater complimentary forage is actually pretty exciting, says Iwaasa.
“Traditionally we haven’t looked at some of these warm season grasses as much as we are now, and that is partly because our growing season has kind of changed a little bit.
“There may be some opportunities where some of these warm season grasses being looked at, and with these legumes that are still actively growing into August, these might represent ways which we can look at extending our grazing season.”