In 2016, the Beef Cattle Research Council’s (BCRC’s) Science Director received 10 letters like this:
“Dear Dr. Bergen…. My name is Emma. I am in 6th grade at Rime Street Elementary. My class found out on vegsource.com that it takes 2,500 liters of water to produce one kilogram of beef. Another site said 25,000 liters…. all these different answers are confusing. My social teacher also showed us a video named Cowspiracy, but it didn’t help. Do you have a dependable answer?”
Eleven-year-olds aren’t the only ones asking these questions. So are consumers, retailers, and others. When the facts aren’t available, exaggerated opinions often fill the gap. A quick google search provides more answers with less consistency. Numbers vary from 100,000 liters/kg (BioScience 47:97-106), 43,000 liters/kg (BioScience 54:909-918); 25,000 liters/kg (Cowspiracy), 16,975 liters/kg (waterfootprint.org) to 15,000 litres/kg (The Economist). A Canadian research team is providing the facts to help us answer these questions, and to help us know how to do better.
A Beef Cluster study led by the University of Manitoba’s Dr. Getahun Legesse Gizaw is measuring how the environmental footprint of Canada’s beef industry is changing. They’ve already reported that each kilogram of Canadian beef generated 15% less greenhouse gas in 2011 than in 1981. A new paper from this team entitled “Water use intensity of Canadian beef production in 1981 as compared to 2011” was just published in Science of the Total Environment.
What they did
Researchers calculated the amount of “blue” and “green” water required to maintain Canada’s beef breeding herd, grow feed, background and finish cattle (including Holstein steers), and process beef in Canada in 1981 and 2011. Blue water (surface or groundwater deliberately used for a specific purpose) mainly includes cattle drinking water used by processing plants, and irrigation. Drinking water was easily calculated; the amount of water cattle drink depends on their age, body weight, weather, and whether they’re lactating. Blue water used to wash carcasses, beef, equipment and laundry in packing plants came from published research, World Bank statistics, and information from packers. Blue water for irrigation came from census information, expert opinion (e.g. types of irrigation systems used for different crops in B.C., Alberta and Saskatchewan), irrigation districts, and provincial government records.
| Blue water = surface or groundwater deliberately used for a specific purpose
Green water = precipitation or rain water |
Green water (precipitation or rain water) used for dryland feed production was much more challenging to estimate. They first determined which pasture types, forages, feed grains and protein crops were most commonly used in Eastern and Western Canada in 1981 and 2011. For example, using annual crops for extended grazing was unusual in 1981 but quite common by 2011. The amount of water required by each crop at different stages of production was determined from published reports. The same crop may have different water requirements depending on when and where it’s grown. For example, barley seeded in July for swath-grazing experiences different growing conditions and has different water requirements than barley seeded earlier for silage or grain. Yield records for each crop came from 82 Census Agricultural Regions across Canada. Rainfall (green water), temperature, and soil moisture records came from 679 weather stations located within agricultural regions of Canada. Animal and crop data were combined into 49 different feeding scenarios.
What they found
In 2011, producing a kilogram of boneless beef in Canada required 459 liters of blue water and 15,485 liters of green water. Over three-quarters of the blue water was used to produce forage and feed crops. Less than a quarter of the blue water used was consumed by animals, and well below 5% was used to process beef. When green water (rainfall) used by feed and forage crops was included, feed and forage production accounted for over 99% of total water use; drinking water was less than 1%, and water used for beef processing was negligible.
The improvements in crop yields have varied drastically in the last 30 years and this has been reflected in the water footprint of the individual crops that are fed. For example, water use intensity of barley over 30 years stayed relatively stable whereas the water use intensity of corn decreased dramatically. This is because we have seen an increase in corn productivity (the average corn yield in Canada increased from 5,770kg/ha in 1981 to 7,400 kg/ha in 2011) due to both breeding and genetics that has not been seen to the same extent in barley.
| Overall it took 17% less water to produce a kilogram of Canadian beef in 2011 than in 1981. |
Overall, it took 17% less water to produce a kilogram of Canadian beef in 2011 than in 1981. This was mainly due to increased reproductive performance, growth rates, slaughter weights and improved crop yields.
What it means
Because beef’s water footprint is mainly due to crop production, shrinking it further will require improved water use efficiency by feed crops and forages through breeding, management, and improved irrigation practices. These steps will reduce the water footprint of agriculture overall, not just for beef production. Further improvements in feed efficiency will also improve the water footprint as well as the greenhouse gas footprint and overall competitiveness of Canada’s beef industry.
Including blue water in the calculations makes obvious sense, because we’re choosing to use that water for a specific purpose. Including rainfall (green water) may seem strange, because we can’t choose where it falls. But we are choosing what the land is being used for. Most of the land and water used for feed production is used by forage crops, which also help support ecosystem services like carbon sequestration, biodiversity and healthy watersheds. In many cases, keeping grass and cattle on the land is an environmentally responsible choice.
It’s also important to remember that these numbers talk about total water use and don’t take into account that while we use water to produce beef we don’t use it up. Water is recycled through the water cycle and returned to the environment for future use.
This research is helping the beef industry answer important questions from the public, and is another example of how improving our production efficiency helps shrink our environmental hoofprint.
If you want to learn more about the water footprint of Canadian beef cattle production, feel free to leave a comment below, or contact one of the researchers:
Getahun Gizaw: Getahun.Gizaw(at)umanitoba.ca
Kim Ominski: Kim.Ominski(at)umanitoba.ca
Tim McAllister: tim.mcallister(at)agr.gc.ca
- Related: The Environmental Hoofprint of Canada’s Beef Industry: Producing beef with lower GHG emissions and using fewer resources – BCRC Blog, January 11, 2016
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We recently received an email from a cattle producer which read:
We raise our cattle on pasture in the foothills of Alberta.
We can not control the rainfall and it generally does not run off. Therefore the rainfall can not be used for any other purpose.
Each cows drinks about 30 litres per day from a pond that does not run anywhere, although it is part of the water table.
Each cow produces a calf of 200 kg each year. Therefore the water used is:
– 30 litres per day x 365 days, divided by 200, for a total of 50 litres per kg.
Delighted to know where my math is wrong?
Here’s the reply to this excellent question from our Science Director, Reynold Bergen:
I did some similar math a few years ago; I might have even used the same drinking water stats as you did. I carried it a bit further (to get the animal to slaughter), and converted it from live weight through dressing percentage and accounted for lean yield (to get rid of bones), and ended up at roughly 80 liters per kg of beef (http://www.beefresearch.ca/blog/cattle-feed-water-use/).
But the numbers you and I came up with are way lower than this new research study. There are a couple of reasons for that.
One difference is that the researchers looked at the effect of the cowherd as well as the feeder calf. You can’t have a feeder calf without the cow, so they needed to account for the water the cow drinks as well (as well as replacement heifers, bulls, etc.). The endpoint plays into it as well; to get to liters per kg beef, they also accounted for the water the calf drinks while it’s in the feedlot.
Turning the finished calf into beef at the packing plant takes water as well, to clean carcasses and equipment. So they accounted for that.
That part was all pretty easy. The water used for drinking water and beef processing are pretty simple to calculate.
But what you and I didn’t do was account for all the water it takes to grow feed. The researchers did that. That’s the real reason the water use per kg beef is so huge in this research study.
Cattle eat a lot, for a long time. The cowherd eats grass, etc. for 365 days per year, and the calves eat grass before weaning and sometimes as yearlings, as well as a lot of silage and grain while they’re being backgrounded and finished. All that grass, silage and grain needs water to grow, whether it’s from rainfall or irrigation.
Estimating this was the hardest part. They used rainfall measurements from more than 600 weather stations around Canada’s agricultural regions. That told them how much water was available. Then they looked at how much water different grass and feed crops need at different points in the season, in order to produce different yields. Then they looked at crop yields from all the different ag regions across the country, and then combined the rainfall, crop requirement and crop yield data together to figure out how much water was actually used to grow those grass stands and feed crops. That’s hard to explain – but the point is that they didn’t just calculate total rainfall and blame it on the cattle (ignoring runoff and infiltration). What they tried to do was figure out how much of that rainfall was actually used to grow the feed.
It’s the water used for growing grass and feed crops that accounts for the dinosaur’s share of water use in beef production. Over 99%, in fact. That’s what makes the number so staggeringly large in this study.
But there are some really good things about this study.
One is that they used internationally accepted methodology to do this, as opposed to the back of the envelope calculations that you and I did, and that a lot of the beef industry’s opponents appear to do.
Another is that the huge water use number the researchers arrived at is far lower than what many anti-beef activists claim it is. So now we have a solid, scientifically defendable number to stand up and say “no, Science says it takes a third less water to produce a kg of Canadian beef than Cowspiracy says”.
Another is that the water footprint of Canadian beef is shrinking; 30 years ago it took 17% more water to produce the same amount of beef than it does now. So Science agrees that the environmental performance of Canada’s beef industry is improving.
And now that we know that grass and feed grain production account for 99% of the water we use to produce beef, it helps us know where to focus efforts to reduce the water footprint still more – by better farming methods, range management, more efficient irrigation, breeding varieties that use water more efficiently, etc.
Two more things.
These footprint studies can be kind of annoying, because they only look at how the potential negative impacts of the beef industry water, and ignore the potential benefits. It’s sort of like assessing my financial health by looking at how much I spend, while ignoring how much I earn. You need to look at both sides of the ledger, so to speak. We know that rangelands are really important for maintaining watersheds – grass allows far more water infiltration back into the groundwater (as you pointed out) than cropland, and allows FAR more water infiltration than cities. We also know that the rain that falls on pastures benefits the soil, and native plants, and insects, and birds, and a wide variety of wildlife – there are real ecological benefits to that. Also, water cycles – producing cattle and beef uses water, but it doesn’t use it up. We know that nearly all the water cattle consume (whether they drink it or eat it) ends up back in the environment through urine or manure or sweat or water vapor. We know that most of the water plants take up from the soil gets transpired back into the air. We know that the water that packing plants take out of the river at one end of the plant goes back into the same river at the other end of the plant. This study did not account for water cycling at all, but this team is doing research on understanding water cycling as well. Water cycling is an even more complicated thing to look at, so we’re fortunate to have a strong Canadian team working on it.
Lastly – here are two videos we helped produce recently. They aren’t about water specifically, but they are about the things the beef industry can do (and does do) to improve our environmental footprint.
This one’s aimed at producers: https://www.youtube.com/watch?v=lz-DsLxipk0
This one’s aimed at consumers: https://www.youtube.com/watch?v=JDSoZBmdudg
I hope this answer helps – let me know if you need more information (but I’d probably have to put you in touch with the researchers themselves for that).
Great answer!