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Musings on how much cattle eat and drink

Charlie Gracey looks at grain and water usage in cattle

Conventional wisdom holds that beef cattle are wasteful users of grain and in direct competition with humans for finite supplies of food grains and water. Thus the large acreages devoted to feed grains might better be deployed in the production of crops directly consumable by humans.

This observation may appear logical on the surface but, as with so many easy assumptions, it requires closer examination. Recently food scientist Sylvain Charlebois of Dalhousie University commented that cattle require “more than 10 pounds of feed and eight gallons of water to produce one pound of edible beef.” The inference most readers would draw from his comment would be that this placed the beef animal in direct competition with humans for a supposedly limited supply of food grains and water.

The debate about the role of beef in our diet should begin with the facts.

So I would offer a more realistic picture of how the bovine, with its marvellous ruminant digestive system, greatly increases and enhances the human food supply by converting plants indigestible by humans into high-quality protein foods from land entirely unsuitable for any purpose other than grazing.

Grain consumption

Let us begin with some basic “factual” information on grain consumption by beef cattle.

The general public often doesn’t realize that the cow herself spends her entire life eating grass or stored forage in winter, although she may receive small amounts of grain as a growing heifer. Her calf is weaned at about 40 per cent of its mature weight on a diet of mother’s milk and grazing. Whether they enter the feedlot as weaned calves, yearling or short keeps, it is fair to say an “average” animal goes on feed at about 55 per cent of its final mature weight having consumed mainly pastures, stored hay and silages, and little or no grain.

In a feedlot its ration consists of a mixture of forages or silages and a grain ration consisting of corn or barley with a small amount of protein supplement. Based on Trends data from Canfax, I calculate cattle in the feedlot consume, on average, 7.2 pounds of grain per pound of live weight gain.

If this grain is applied to the final weight of the animal, as it should be, grain consumption works out to 3.3 pounds of grain per pound of final live weight.

This ratio of usage is expressed in terms of live weight and must next be converted to actual boneless beef. An average beef carcass weighs 60 per cent of the live animal weight but the amount of boneless beef in a carcass averages 42.6 per cent of the live animal weight.

The rest is not wasted, tighten your belt or look at your shoes… I’ll leave it there. So, if it took 3.3 pounds of grain to produce one pound of live weight gain, that converts to 7.7 pounds to produce one pound of boneless beef.

Even though this is well below the “more than 10 pounds” commonly mentioned, it’s not the whole story. Annually 16 per cent of the total beef supply is produced from culled cows and bulls that consume negligible amounts of grain, aside from that consumed by dairy cows to support milk production. Therefore our figure of 7.7 pounds applies to only 84 per cent of the boneless beef when spread over total annual production, so the correct figure for grain usage by the beef sector is about 6.5 pounds of grain to produce one pound of boneless retail beef. That indeed is a far lower ratio than is commonly used to describe grain consumption in beef production.

Water usage

What about the allegedly high water use in beef production? Drinking water requirements for cattle vary from a low of about 20 to a high of 65 litres per day depending on the type of cattle and the temperature. Recognizing this variability, a generous overall average daily consumption of 45 litres per day for a steer or a heifer means that at an average slaughter age of 18 months the animal has consumed 25,000 litres of water. The mother cow, meanwhile, would have consumed an additional 18,000 litres, which I will round up to 20,000 litres to accommodate the sire. Recall that the sire is sire to approximately 20 offspring per year so his water consumption can be spread over that number of offspring.

So the water requirements to produce a finished steer or heifer totals roughly 45,000 litres. The output is a steer or heifer carcass weighing approximately 380 kg. (I am ignoring the fact that the culled cow and bull also contribute to the beef supply). So that means that 45,000 litres of water were consumed in the production of a 380-kg carcass. That works out to about 118 litres of water per kg of carcass weight or 162 litres per kg of boneless beef.

So it is apparent the claim that eight gallons of water is needed to produce one pound of beef (equates to 80 litres per kg of edible beef) is a considerable underestimation. Probably the lower estimate of 80 litres referred only to water consumption in the feedlot and did not include the water consumed by the animal before it arrived in feedlot or the water consumed by the dam and sire.

But what does this mean? Certainly a large volume of water is used in beef production and, as I have shown, in almost exactly double the amount claimed. But so what? Water, especially water used in agriculture is the ultimate renewable resource and every drop of it is returned to nature to be used again and again. All of the water used to produce that pound of beef, except the moisture content of the beef itself, was back in nature before the animal was marketed. Not one drop was destroyed or wasted. Water usage in beef production becomes an issue only where it is scarce and is needed for other more urgent purposes and that is not a problem in any of the beef-producing regions of Canada.

With the math explained we can move on to the main question. Does the production of feed grain for livestock compete with food grain production in Canada?

The approximate total annual grain and oilseed production in Canada presently is 75 million tonnes. Coarse grains production, which includes feed grains, contributes roughly one-third of that supply. About half of the coarse grain supply is used for industrial purposes, such as malting, and the other half, about 14 million tonnes, is used as feed grains for cattle, hogs, poultry and all the minor livestock species. Currently, the prices of all grains are somewhat depressed and would be even lower were it not for the demand for feed grain exerted by the livestock sector. In addition to consuming feed grains, livestock are the only outlet for the significant but variable quantities of weather-damaged food grains. Without the livestock industry these off-grade food grains would be wasted.

So if one looks at the situation in a balanced way, one can see that by utilizing forage crops, pastures and a modest amount of feed grain, beef cattle provide high-quality, protein dense beef to augment the human food supply. It is true that they consume quantities of feed grains during the feedlot stage but much less than is commonly supposed. As well, they make beneficial use of lower-quality or spoiled food grains and other crop residues that have no other use or value.

It is possible to finish cattle solely on forages but it takes longer, and would take up much of the land currently devoted to feed grain production, with little if any reduction in cost. The grain portion makes up only about 23 per cent of total cost of production in the feedlot.

So should beef production be reduced in an effort to increase the global food supply? Far from improving either the quantity or the nutritional quality of the human food supply, this would result in a lower supply of high-quality protein and a sharp reduction in the total supply of human food.

To understand this apparently illogical observation one has only to recognize that vast areas of land on every continent are unsuited to the intensive cultivation necessary to produce food grains, fruit and vegetables. Even better farming land benefits from crop rotations with forages and applications of livestock manure to improve soil tilth and fertility. So, to reduce or eliminate beef production would mean that the large acreages of land that are suitable only for grazing could no longer make any contribution to the human food supply. Of the 160 million acres of agricultural land in Canada, 50 million acres are described as pasture land, meaning tame and natural pasture land. An additional 17 million acres are devoted to tame hay.

It might be prudent to recall the devastation visited upon vast areas in Canada and the United States during the Dirty Thirties when millions of acres of fragile soil were put to the plow in response to temporarily high wheat prices. The lesson learned then that some land should remain in grass should not be so quickly forgotten. Humanity has centuries of experience with balancing livestock and crop production and only very recent and localized experience with agriculture without livestock.

Charlie Gracey is a beef industry analyst living in Ontario. More detail on this topic is available on his website at www.charlesgracey.net.

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Charlie Gracey is a beef industry analyst living in Ontario. More detail on this topic is available on his website at www.charlesgracey.net.

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Comments

  • Philip

    A good discussion of a misunderstood issue. The balance might shift against beef in this respect over the next 30+ years when we’re feeding a few billion more people on this planet with the same amount of productive land I guess, but for now…

    If we can come up with a neat fix to the other issue people raise with beef, the contribution of the rumen methane to climate change, we’ll be sorted!