Environmental Impact – Page 3

Can we feed up to 10 billion people in 2100 by improving crop yields, reducing deforestation, and reducing meat and dairy consumption? These solutions are among those suggested by Jonathan Foley at the University of Minnesota’s Institute of the Environment to enable the increase in food production required by the future global population. These are logical suggestions, yet the proposal that meat and dairy consumption should be reduced is likely to be the most-debated, particularly as livestock industry stakeholders may regard this as yet another attack on animal agriculture.

The futility of the “Meatless Mondays” campaign has been discussed ad infinitum, yet in contrast to the EWG’s recent report, Foley does not attempt to promote a vegetarian or vegan ideology or to suggest that climate change could be reversed if only we all ate humanely-certified or organic meat. Instead, the report concludes that resources could be saved if we shifted to meat consumption towards pork and poultry production as:

…it takes 30 kilos [66 lb] of grain to produce one kilo [2.2lb] of boneless beef… We’re better off producing grass-fed beef or more chicken and pork, which requires far less grain feed

Based on those data, Foley’s conclusion is entirely logical. However, as Carl Sagan said, “Extraordinary claims require extraordinary evidence” – and here the evidence is lacking. A recent review of feed efficiency by Wilkinson reports that monogastric animals require 4.0 kg (swine) or 2.3 kg (poultry) of feed per kg of gain. Monogastrics are indeed considerably more efficient than their ruminant counterparts as beef animals require 8.8 kg feed per kg gain – considerably more than swine or poultry, but far less than Foley’s estimate.

It would be convenient to argue that the errors in Foley’s feed efficiency data (not to mention religious limitations on pork consumption) negate the report’s conclusions. But isn’t it logical to argue that we should eat meat produced in systems that use fewer resources to produce animal protein? Personally, I spend more than half my time traveling to present precisely that message to the animal industry and to encourage livestock producers to improve efficiency. I absolutely believe that we need to improve productivity and efficiency in order to feed the growing population. However, traditional feed efficiency data have a major flaw – it’s assumed that all animal feed could otherwise be used to feed humans.

Wilkinson suggests that the traditional concept of feed efficiency be re-examined to reflect the quantity of human-edible crop inputs that are used to produce a unit of energy or protein from animal products. For example, humans cannot digest pasture, only 20% of the nutritional value of oilseed meals can be utilized for human food and yet 80% of nutrients within cereals, pulses and soybean meal are human-edible. By partitioning out the human-edible component of animal feed, Wilkinson demonstrates that the human-edible energy feed efficiency ratios for pork and cereal beef are similar (Figure 1*) and that dairy production actually produces twice the amount of human-edible energy than it uses (input:output ratio of 0.5). On a protein basis, cereal beef has a higher human-edible protein feed efficiency ratio (3.0) than pork (2.6), but suckler beef systems where cattle are grazed on pasture again produce more human-edible protein than they consume (input:output ratio of 0.9, Figure 2*). Not only are these revised feed efficiency estimates considerably lower than those quoted by Foley, but they underline the importance of herbivorous grazing animals in utilizing human-inedible forage to produce animal protein.

Numbers have power – it’s always tempting to base a suggestion around a single data point that “proves” the argument. Feed efficiency is a useful metric, but as we face an ever-increasing challenge in balancing food demand, resource availability and consumer expectations, it’s critical that we examine the bigger picture. The ruminant animal has a major evolutionary advantage in its ability to digest forages – we may be better acquainted with the human dietary advantages of probiotic bacteria than our ancestors, but until we are equipped with human rumens (humens?) we cannot hope to effectively make use of all crop resources.

*The importance of acknowledging the human-edible component of feed efficiency was part of my presentation at the Alltech Ruminant Solutions Seminar in Ireland this week – to go to a PDF copy of my presentation please click here.

Would you replace your hamburger with a soy burger?

Ah, the power of a report from an earnest non-governmental organization, out to save the consumer from themselves. Destined to be selectively quoted for the next 20 years and to prove once and for all that, as the comedian Ron White would say: “You can’t fix stupid”.

Released this week, the Environmental Working Group’s report, claimed not only that everybody should eat less meat, but that “Meat, eggs and dairy products that are certified organic, humane and/or grass-fed are generally the least environmentally damaging…Overall, these products are the least harmful, most ethical choices.” This is a surprisingly intuitive conclusion in that it utterly contradicts the body of scientific knowledge to date, and as the report doesn’t contain any data on anything other than conventional production systems, let alone ethics.

The requisite environmental activist components are there: stylized pastoral scene on the cover and such a liberal sprinkling of emotive words such as “confined” and “polluting” it seems like an ice-cream sundae assembled by a small child with a sugar addiction. It’s even been peer-reviewed by “experts” (as you may have gathered, when reading this post, words in quote marks should be accompanied by an ironic raised eyebrow).

So who are the experts? An RN who teaches “culinary skills and management”, an Assistant Scientist interested in “access to sustainably produced and healthy food”, another whose program aims to “address the environmental and public health impacts of industrial agriculture and promote more sustainable alternatives”. Methodology reviewers were the aforementioned Assistant Scientist, an expert in tropical forests and the daughter of the founder of the Small Planet Institute. What’s the link here? An interest in “sustainability” – which in this case means community-supported agriculture, local food, and nutrition. Where are the experts in livestock production? Who checked with animal and meat scientists, industry professionals, extension agents, nutritionists or processors who can verify that the assumptions made within the report are correct?

It’s a bona-fide report with colorful graphs, acknowledgements, a whole separate report on the methodology (which guarantees nobody will read it) and data! As we all know, data is powerful. According to their “calculations”, lamb has the greatest impact, generating 39.3 kg (86.4 lbs) of carbon dioxide equivalents (CO2e) for each kilo eaten, and beef has the second-highest emissions, generating 27.1 kilos (59.6 lbs) of CO2e per kilo consumed. Cheese generates the third-highest emissions, 13.5 kilos (29.7 lbs) of CO2e per kilo eaten. Everybody knows that data doesn’t lie. Cold hard numbers are based on science. Yet just as I can replace ground beef with tofu and make something that looks like a burger, yet tastes like… soy, so has the EWG have used poor-quality data and erroneous assumptions to create a vegetarian ideology that is a poor substitute for real science.

They claim that if everyone in the U.S. chose a vegetarian diet, it would reduce US carbon emissions by 4.5%. This is an impressive achievement since the Environmental Protection Agency cites livestock production (including dairy, eggs and horses) in the US as accounting for 3.12% of total emissions. Who knows where that extra 1.4 percent comes from?

The animal component of the report shows a lamentable lack of basic livestock production knowledge. In the beef example, the cow-calf and stocker operations are based on a lot feeding system in Nebraska rather than rangeland production and by-product/forage feeding. All the animals raised are steers (what on earth happens to the heifers?) and there appear to be no bulls in the system, not to mention the lack of dairy calves entering the feedlot and cull beef or dairy cows entering the production chain. Crucially there is no data on herd dynamics, bodyweights, growth rates, and total time required for animals to reach slaughter weight – the most important factors that affect the carbon footprint of a unit of beef.

The lamb system does contain rams as well as ewes, but there is no data relating to the flock, and most crucially, to the lambing rate. US farm flocks average 1.5 to 2.5 lambs per ewe per year whereas range flocks average 1.0-1.5 lambs per ewe. If we compare this to the US average for beef according to the most recent USDA/NAHMS report of 87% of cows producing a live calf, that means we need roughly twice as many beef cows to produce offspring as we do ewes, even considering the fact that lamb produce slightly less meat per carcass on a percentage basis (for a more realistic estimate of meat yields than those quoted in the EWG report, the University of KY have a nice extension publication on the subject).

So here it is, the issue that every single life cycle assessment involving animals and executed by LCA engineers to date misses – the fact that for every day an animal is alive, it needs a certain amount of energy and protein (and therefore feed, land, fertilizers, fossil fuels etc) simply to stay alive. This is called the maintenance requirement and it’s exactly the same principle that leads to that nifty “The average woman requires 2,000 calories, the average man requires 2,500 calories” credo that’s on almost every nutritional label. It doesn’t take a giant deductive leap to realize that if a certain amount of feed is needed to maintain an animal, there’s going to be a certain amount of waste too – which means manure and greenhouse gases. Breeding animals in meat production are the biggest contributors to the total carbon footprint precisely because they consume resources and emit greenhouse gases each day, yet only end up in the human food chain after a number of years, if at all.

If I’m making a bun for my tofu burger, it’s more efficient to cook it in an oven that can produce two or three buns rather than one. Exactly the same analogy applies to breeding herds – a larger breeding herd with reduced reproductive efficiency (i.e. fewer offspring per female), means more resources and a greater carbon footprint per unit of milk or meat. Lamb’s carbon footprint would be expected to be approximately half to two-thirds that of beef given the greater reproductive efficiency, yet the EWG’s estimation has lamb at 44% higher – a clear reflection of the invalidity of their results.

Comparing the carbon footprint of different meat products is an elegantly futile competition in which nobody wins. According to their “data” beef is a better choice than lamb, chicken is better than pork. Yet who fancies chicken Wellington for dinner? Or egg pot pie? Or a pea McMuffin? The idea that we should be happy, saving the world on a diet of tofu and lentils is somewhat ironic given their propensity to produce increased methane from the human gastro-intestinal tract.

Are all 311 million people in the US going to rush to the grocery store and fulfill the EWG’s somewhat desperate cry for Meatless Mondays? Until all human activity can be put into context and the effect of driving to work vs. buying French wine vs. eating an 18-oz T-bone vs. having a third child can be compared objectively, this report is simply another one-week-wonder, destined to be quoted in every vegetarian manifesto and vegan twitter post (presumably vegans don’t tweet, as that would be exploiting birds?) but forgotten as soon as Katherine Middleton wears a new dress on a royal visit or yet another politician demonstrates their indirect support for the pork industry by increasing Google searches for “wiener”.

For a little light relief, here’s Ron White’s take on “Stupid” (please do not watch if easily offended)