Category Archives: Feed Efficiency

Jamie Oliver Should Be Presenting Friday Night Farming Facts – Not Feasting On Foodie Fiction

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Commercial dairy cows in Cumbria – should they be “retired” before slaughter?

Good grief. Just when I think I’ve heard it all, another food pundit comes up with an idea so daft that you could bottle it and sell it as vegan, gluten-free, dairy-free, humanely-reared organic water. The latest brainwave from Jamie Oliver is to “retire” old dairy cows onto pasture, where they can graze for four years before producing highly-marbled beef. Contrary to most of the breed-related marketing, Holstein beef is pretty good, so it’s a mouth-watering concept until we take a step back and think about the actual sustainability impacts.

Producing beef from cull dairy cattle? Excellent idea. I once had a heated argument with an activist protestor outside the Smithsonian Museum in Washington DC who seemed surprised that, when he told me that most cull dairy cows end up as burgers, I didn’t renounce my heathen ways and immediately seek out the nearest tofu burrito. It makes perfect sense – where would be the logic in discarding an entire cow’s worth (~301 kg) of nutritious, delicious beef simply to bury, burn or use the meat for non-food purposes? Indeed, ~50% of the UK (and ~24% of the US) beef supply comes either from cull dairy cows or dairy calves reared for beef.

Is there an argument for giving extra feed to cows that are going to be culled so that they get a little fatter and produce tastier beef? Yes indeed, adding value to cull dairy cows is a great idea, especially when the beef price is high. But here’s the rub. The average dairy cow in the U.K. is culled at 6.4 years of age. By that time she should have reached her mature weight, which means that the majority of extra weight she puts on in “retirement” is fat. Although we love the streaks of intramuscular fat that we see in a steak (marbling) and enjoy the depth of flavour that gives to the meat, the vast majority of fat on a carcass isn’t particularly edible. So we’re feeding a cow for four years of retirement in order to discard (or rather render into tallow – perhaps to make some £5 notes?) a significant proportion of the weight that she gains.

A cow will eat 2-2.5% of her body weight in dry matter every single day. Four years of feeding a 700 kg cow = 4 x 365 days x 700 kg x 0.025 = 25,550 kg of feed dry matter, or 106,458 kg of fresh grass given that it’s only ~24% dry matter. Plus 4-years worth of drinking water, manure and greenhouse gas (GHG) emissions. A hefty environmental impact compared, for example, to rearing two beef steers on the same amount of pasture over a 4-year period, in addition to culling the dairy cow when she leaves the herd (sans retirement). That scenario would provide 200% more beef (~900 kg total, even allowing for the lighter weight for grass-finished vs. grain-fed steers) from the same amount of pasture and with a smaller total quantity of manure and GHG emissions because the growing animals are lighter in weight throughout, therefore excrete and emit less*.

I can’t decide whether the increasingly asinine proposals for sustainable food production propounded by Jamie Oliver’s “Friday Night Feast” programme, which recently left the casual viewer with the impression that welfare of housed dairy cows is equivalent to that of battery hens are serious, or simply a way to court fame through controversy. However, the number of tweets lauding the programme’s food philosophy is alarming given the amount of time devoted to non-sustainable ideology. Time for TV programmers to redress the balance with some Friday Night Facts vs. Fiction?

*Note that I have not accounted for the beef cows needed to produce the steers, nor for the cost of rearing the dairy cow or the heifer needed to replace her in dairy herd. This is not a full system assessment, but simply about the best use of a unit of pasture area – adding fat to a mature cow (less efficient) or adding muscle and fat to growing animals (more efficient)

Seeing the Bigger Picture – Why One-Dimensional Panaceas Do Not Solve Sustainability Issues

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This week, another paper has been released claiming that we should change to a vegetarian diet in order to “…cut global food emissions by two thirds and save millions of lives“. As ever, media coverage of the paper by Springmann et al. ignored salient points regarding the importance of increasing fruit and vegetable consumption and reducing energy intake in reducing deaths from heart disease, cancer and diabetes; and simply focused on the claim that reducing meat intake would improve health and cut greenhouse gas emissions (GHGs). The simple message to the consumer? Go vegetarian.

So are GHGs the only important environmental metric? Absolutely not. What about land use? Air quality? Fossil fuel consumption? Water use? Biodiversity? The myopic focus on GHGs as the only arbiter of environmental sustainability completely ignores these factors, yet the results of the current study (and similar papers) are promoted worldwide as a panacea to solve all environmental issues.

Can you imagine a world where we only look at one consequence of our actions? Where our only consideration when buying a car is the colour of its paint? Or the criteria for accepting a new job is whether they have good coffee in the canteen? Surely a ridiculous idea – all of our actions have direct and indirect consequences, some predictable, some entirely unforeseen, and we weigh up these outcomes with every decision that we make – including dietary choice. If we examine a number of the assumptions and recommendations within the current paper, it’s apparent that the negative consequences of the one-dimensional GHG focus may outweigh any benefits gained.

Although a regional approach was used to assess population health impacts, greenhouse gas emissions in the paper were based on reference values for various foods, with the inherent presupposition that all livestock production systems are equally productive and efficient. This is a fatally-flawed assumption. If we take beef as the example: in the USA, 90% of cows have a calf every year, cows first calve at 24 months of age and growing cattle are slaughtered at 15 months of age. By contrast, in Brazil, 60% of cows have a calf every year, cows first calve at 36 months of age and growing cattle are slaughtered at 42 months of age. Both systems are suited to the resources and market available, but have wildly different efficiencies. Consumption of a US-produced steak (16.7 kg CO2/kg) will therefore have a far lesser contribution to the average person’s carbon footprint than a Brazilian steak (62.0 kg CO2/kg).

All food have an environmental impact

Replacing milk, meat and eggs with plant-based foods (legumes, nuts, etc) is entirely possible, yet it does not occur at zero environmental cost. Every single food that we consume has an environmental impact, and although the greenhouse gas emissions associated with a unit of lettuce or beans may be less than pork or beef (asparagus is a notable exception), the land required to produce equivalent energy or protein from plants is significant.

We cannot simply remove cattle from the low-quality range and pastureland that they occupy in the majority of grazing regions and assume that we can plant brussels sprouts or soybeans instead. Only a small percentage of pastureland is productive enough to produce human food or fibre crops (8.0% in the USA and 10.8% in the UK). The fact that pastureland would have to be converted to cropland, releasing sequestered carbon dioxide to the atmosphere and increasing the use of fertilisers and irrigation water, was not accounted for in Springmann et al.’s study. Indeed, from where would we source fertilisers for crop production if we significantly cut meat consumption and thus livestock populations? Is an increased reliance on dwindling reserves of inorganic N, P and K really a sustainable solution?

Finally, and most importantly, cattle do not simply exist as a source of milk or meat. In many developing countries, immense cultural significance is placed upon livestock ownership and ruminant animals play a vital role in supplying draught power, capital assets and agricultural enterprise diversification. Should a single mitigating factor for reducing GHG emissions overcome the moral obligation to support and assist subsistence farmers in developing regions? It’s vital that we take a holistic view that encompasses environmental responsibility, economic viability and social acceptability in order to improve food system sustainability rather than simply focusing on one aspect of the problem. Rather than taking a whole-system approach to environmental and human health, the study by Springmann et al. is akin to amputating both legs in order to try and cure arthritis. Short-term pain may be reduced, but long-term suffering is inevitable.

Beef is Killing the Planet…and Elvis is Riding a Rainbow-Belching Unicorn

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BurgerMy Twitter feed just exploded. Yet another study has been released claiming that if we all just gave up beef, the planet would be saved, Elvis would come back from the dead, and rainbow-belching unicorns would graze the Northern Great Plains. I may have exaggerated a little with the latter two claims, but the extent of media coverage related to the paper “Land, irrigation water, greenhouse gas and reactive nitrogen burdens of meat, eggs and dairy production in the United States” seems to suggest that the results within are as exciting as seeing Elvis riding one of those unicorns…but they’re also about as believable.

Much as we’d all like to stick our fingers in our ears and sing “La la la la” whenever anybody mentions greenhouse gases or water footprints, we cannot deny that beef has an environmental impact. Yet, here’s the rub – so does every single thing we eat. From apples to zucchini; Twinkies to organically-grown, hand-harvested, polished-by-mountain-virgins, heirloom tomatoes. Some impacts are positive (providing habitat for wildlife and birds), some are negative (nutrient run-off into water courses), but all foods use natural resources (land, water, fossil fuels) and are associated with greenhouse gas emissions.

So is this simply another attack on the beef industry from vegetarian authors out to promote an agenda? Possibly. The inclusion of multiple phrases suggesting that we should replace beef with other protein sources seems to indicate so. But regardless of whether it’s part of the big bad vegan agenda, or simply a paper from a scientist whose dietary choices happen to complement the topic of his scientific papers, the fact remains that it’s been published in a world-renowned journal and should therefore be seen as an example of good science.

Or should it?

I’m the first to rely on scientific, peer-reviewed papers as being the holy grail for facts and figures, but there’s a distressing trend for authors to excuse poor scientific analysis by stating that high-quality data was not available. It’s simple. Just like a recipe – if you put junk in, you get junk out. So if one of the major data inputs to your analysis (in this case, feed efficiency data) is less than reliable, the accuracy of your conclusions is….? Yep. As useful as a chocolate teapot.

Feed efficiency is the cut-and-paste, go-to argument for activist groups opposed to animal agriculture. Claims that beef uses 10, 20 or even 30 lbs of corn per lb of beef are commonly used (as in this paper) as justification for abolishing beef production. However, in this case, the argument falls flat, because, rather than using modern feed efficiency data, the authors employed USDA data, which has not been updated for 30 years. That’s rather like assuming a computer from the early 1980’s (I used to play “donkey” on such a black/green screened behemoth) is as efficient as a modern laptop, or that the original brick-sized “car phones” were equal to modern iPhones. If we look back at the environmental impact of the beef industry 30 years ago, we see that modern beef production uses 30% fewer animals, 19% less feed, 12% less water, 33% less land and has a 16% lower carbon footprint. Given the archaic data used, is it really surprising that this latest paper overestimates beef’s environmental impact?

The authors also seem to assume that feed comes in a big sack labeled “Animal Feed” (from the Roadrunner cartoon ACME Feed Co?) and is fed interchangeably to pigs, poultry and cattle. As I’ve blogged about before, we can’t simply examine feed efficiency as a basis for whether we should choose the steak or the chicken breast for dinner, we also have to examine the potential competition between animal feed and human food. When we look at the proportion of ingredients in livestock diets that are human-edible (e.g. corn, soy) vs. inedible (e.g. grass, other forages, by-products), milk and beef are better choices than pork and poultry due to the heavy reliance of monogastric animals on concentrate feeds. By-product feeds are also completely excluded from the analysis, which makes me wonder precisely what the authors think happens to the millions of tons of cottonseed meal, citrus pulp, distillers grains, sunflower seed meal etc, produced in the USA each year.

Finally, the authors claim that cattle use 28x more land than pigs or poultry – although they acknowledge that cattle are raised on pasture, it’s not included in the calculations, which assume that cattle are fed feedlot diets for the majority of their life. This is a gross error and underlines their complete ignorance of the U.S. beef industry. Without cow-calf operations, the U.S. beef industry simply would not exist – efficient use of rangeland upon which we cannot grow human food crops both provides the foundation for the beef industry and creates and maintains habitats for many rare and endangered species of plants, insects, birds and animals.

Want to know how to reduce the environmental impact of food production overnight? It’s very simple – and it doesn’t involve giving up beef. Globally we waste 30% of food – and in developed countries that’s almost always avoidable at the consumer level. Buy the right amount, don’t leave it in the fridge to go moldy, and learn to use odd bits of food in soups or stews. Our parents and grandparents did it out of necessity – we can do it to reduce resource use and greenhouse gas emissions; and take the wind out of the sails of bean-eating anti-beef activists.