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COLUMN: Is climate change responsible for a reduction in protein in plants?

In the Cariboo we are hoping to establish and alliance between the universities and all the agricultural stakeholder groups in our Interior region.
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There have been some early identifiable shifts in climate that may be affecting the quality of the food cattle eat: forage (grass and forbs), David Zirnhelt notes in his latest column. Monica Lamb-Yorski photo

David Zirnhelt

Special to the Tribune Advisor

Recently, I participated in a panel of agriculture producers presenting to a network of agriculture researchers in the Lower Mainland.

They are part of an emerging network organized for collaboration between researchers in the various institutions of higher education in B.C.

In the Cariboo we are hoping to establish and alliance between the universities and all the agricultural stakeholder groups in our Interior region.

In February we will hold a winter workshop to move this idea forward and identify “applied” research priorities.

“Applied” refers to the idea that the research involves producers.

Hopefully the results of the on farm trials and research will be applicable to producers in this area.

There have been some early identifiable shifts in climate that may be affecting the quality of the food cattle eat: forage (grass and forbs).

Here is one such idea.

The idea that we (industry, government and researchers) should investigate this was put forward by one of our eminent researchers, Dr. John Church, Chair of Beef Cattle Sustainability at Thompson Rivers University, Kamloops campus.

He said at this conference that there were a couple of priorities for research investigating the impact of climate change on the cattle industry: heat stress on cattle and the effects of changes (reduction) of forage nutrition on meat quality.

I asked him for his evidence on this idea.

He forwarded me this article from Iopscience, Environmental Research Letters, Vol 12, Number 4, April ,2017,“ Long-term declines in dietary nutritional quality for North American Cattle.

Just so I cannot be accused of plagiarizing, I am quoting verbatim from the conclusion of this article. (CP is crude protein and DOM is digestible organic matter):

If the drivers of the reduction of protein in plants cannot be identified and reversed, or adaptation strategies enacted, the protein debt is only likely to grow, which might begin to cause a net decline in cattle production barring further improvements to cattle genetics.

The consequences of declining [CP] and increasing [DOM]:[CP] extend beyond greater nutritional stress as they would also promote greater methane production, which could serve as a positive feedback to warming (Johnson and Johnson 1995).

Barring wide-spread mitigation of reduction in greenhouse gases, scenarios for adaptation should begin to be examined unless reductions in forage quality are to be tolerated.

In response to declining forage quality, managers could also opt to increase the use of N fertilizer for hay production, promote N2-fixing plant species, increase transport of hay and supplemental feeds, and/or increase the seasonal transport of animals from lower protein areas to higher protein areas (Zilverberg et al 2011, Joyce et al 2013).

Among the most likely efforts to be attempted, the economic viability and ecological consequences of increasing nitrogen availability on grasslands to counter the growing protein debt will need assessment.

Columnist David Zirnhelt is a member of the Cariboo Cattlemen’s Association and chair of the advisory committee for the Applied Sustainable Ranching Program at Thompson Rivers University in Williams Lake.