342 - Fewer cows | Scoins.net | DJS

342 - Fewer cows


Following on an idea in the April snippets, I started to wonder about the acreage required for a tonne of meat compared with a vegetable crop. It rapidly becomes clear that one should be looking at that land used for meat that could instead be used for crops; there is little point in viewing a chunk of mountainside on which we put sheep (though 'allow' would be a better word choice) as a place on which we could grow vegetables or edible grasses. We need to compare like with like.

At the same time and also in the snippets for this month, I've been wondering about being snippy with the missus and what causes those conflicts. Result, I want to have fewer cows and hence the title.

Research show that 4 tonnes of cereal grain per hectare was typical in 1975, but 7 was typical for 2004 [1]. ¹ The sensible working unit for meat is the livestock unit, LU, which makes this meat an annual crop and [2] intensive grassland management in Ireland gives 2.47 LU per hectare (one per acre, which suggests that unit had some pretty good original basis). ²  That isn't finished meat, though 'finished' is the term for the animal ready for slaughter. 300-350kg of carcass might be a typical figure, making around 800kg of cow per hectare, Which is 10-20% of the tonnage from the best crops. The figures for meat are very variable, like those for cereal, so perhaps we ought to stick with the lowest yields for each and think of beef as around 15% of cereal yield on similar land. There is a significant assumption that the lowland pasture on which animals are raised would lend itself well to crop instead, so in further thinking, even if I don't use the number, I'm going to use a 4t/ha for crops rather than the wonderful 7t/ha. As ever, just because that's a national average doesn't mean that you local farmer produces that much; my neighbour in Cornwall called 7t/ha a bad year for potatoes.

There is an implicit assumption that, in declaring mass of food per unit of area, that these are themselves suitable equivalents. If we cam measure meat as 15% of a comparable common arable crop by weight, then we also ought to check that a kilo of meat is equivalent to a kilo of cereal in a diet. Here's a table confirming that the total carbohydrate is about the same, but most fruit, vegetables and grain score lower in protein, with (the worst, in this sense) root vegetables at around 60% of meat, fish and eggs. So, still at worst, we might see the equivalence of moving protein as not 15%  of cereal yield but 25% (dividing by 60%). So that's a factor of four, long before we wonder whether we could use pasture for more than just meat. The at-least take-away, with all the implied caveats is; meat takes four times the land as arable, when the land could be used for either.

The UK has an area of 24.2495Mha (Mha = Million hectares; 242495 km²). Of this, 17.3 Mha, or a bit over 70% is recognised as utilised agricultural land, as recorded by DEFRA [3].³  Of this 17.3Mha, some 6Mha is croppable land and typically we have 4.4-4.8Mha actually under crops in any year. Horticulture, which means vegetables, fruit, glasshouses and so on, is a mere 0.166Mha.⁴  Keeping this in context, we generate about 60% of what we consume. 2022 edit: This disagrees with an oft-quoted figure that we import 45% of what we eat (essay 388.4) but it may that both figures are true; read on.  The 11Mha that we use for animals is definitely not all swappable from pasture to arable but some of it could switch to 'croppable', with attached costs. The significant gap between croppable and actually cropped suggests that a lot of this difference is lying fallow or used for sensible crop rotation—which often means it is used for animal feed—so it would be wrong, I suggest, to jump to a conclusion that we could overnight increase the croppable land by a third, from 4.5 to 6Mha. A lot of our livestock is kept on land we know we couldn't easily use for crops instead and I'd like to think that statement could be debated. We don't use all cropped land for human food; quite a lot goes to animal food and quite a lot goes into alcohols (beers, whiskies, etc) while a little (rape) goes into other oils not all eaten.

You might read the Land Study [1] in full: it looks at the feasibility of the UK feeding itself (self-sufficiency in food, which we more-or-less managed through WW2) and produces some models from which a calculation is made about the land required to do that. These figures often disagree with what I've already quoted but that doesn't invalidate the arguments at all – and there is sufficient detail provided that you could fiddle with the model yourself if you wished. I've included one of the tables here, so that you might feel inclined to read more, or indeed just be happy that someone has done some of the thinking and you could read it if/when you're bothered enough.

A general move away from cattle means an associated move away from dairy. Sheep are less of an issue since, though we grow more sheep than other European nations [3, p12], we generally do that on rough grazing for which we have very little other use in terms of agriculture. Though we might well argue for a lot more trees, we have an awful lot of land suitable for that, mostly moorland, and we could do that quite easily. Milk cows [1, p21] produce something in the order of 3600 to 4800 litres of milk per year, where the calves provide the beef supply and replenishment of the herd, but they also consume a tonne of grain each per year at those yield levels.

I suggest that in looking at changing our diet(s) to radically less meat we have a direct connection to a reduction in dairy. This particularly requires us to look at milk. While living in China I was very aware that the national diet consumed very little dairy and that most of what was called milk was soy milk. Plant-based milks are therefore a growing field. ⁵ Ha!

DJS 20210430

Top pic from the India Times thanks to Google images.

Related pages: 388.4 Food security - Milk The notes below the referenced sources are lengthy and detail, for example, why one might prefer oat milk over cow, under [105] there. We switched on discovering this content, though not immediately.

 ²   ³  ⁴  ⁵  ⁶ ⁷ ⁸ ⁹ 

1  https://www.thelandmagazine.org.uk/sites/default/files/can_britain_feed_itself.pdf

2  https://www.researchgate.net/post/How-to-calculate-the-land-requirements-of-1-kg-meat-pork-chicken-sheep-beef-1-litre-of-milk-dairy-cattle-and-1-dozen-eggs

 https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/946161/structure-jun2020final-uk-22dec20.pdf  This is well worth a browse; it's only 30 pages.

4 Plant-based milks https://foodrevolution.org/blog/milk-substitutes/


In modern intensive dairy farms, it is common to replace 1/3 of the lactating herd every lactation. Consequently, about half of the animals on a dairy farm are not lactating and the feed resource dedicated to rearing new animals is a burden to farm efficiency. The efficiency news is better once a cow begins lactating, as a high producing dairy cow uses about 60% of her feed for producing milk and only 40% for maintenance. Resource efficiency in modern dairy operations can be further improved by increasing animal productivity, and by reducing culling rates. Examples from commercial farms point to the feasibility of combining high productivities and longevities. This combination approach results in economic efficiency, minimises the environmental footprint of milk production and positively relates to animal welfare. It is not common, but examples of cows yielding more than 100,000 kg of milk in their lifetime expose the opportunity for a next level of efficiency in dairy farming.

Even when viewed in terms of the protein fed to a dairy cow or broiler chicken vs. the food protein they produce, performance is comparable. Chickens retain dietary protein very efficiently as they grow, but they yield food protein in meat fractions (breast, thigh, drumstick, wing). In contrast, 100% of the protein the cow yields in milk is food protein. This is another example illustrating that standard approaches to measure efficiency are imperfect to describe the complexity of food production efficiency.

I'm not prepared to say that this content is wrong, but I'd believe it much more readily if the conclusions were linked to supporting documents, even if only another unsupported opinion. Then one can in some sense judge whether this is echo-chamber, biased reportage or (what is wanted) genuine content. The result with me is that I think some of the content is spot on ("replace a third of the herd every lactation", for example) while some—the whole of the second paragraph above—I want a lot of additional detail available; what is not being said here, even if the bald statement is true?

 1 Can Britain feed itself? In 1975, Britain grew 15 million tonnes of cereals on less than 3.6 million hectares at a yield of about 4 tonnes per hectare. A ley, used in the table here, is temporary pasture rotated with crops. Tillage is always under crops, rough grazing is land that would not be used for crops. Arable means crops, pasture means animalsIn 2004 Britain grew nearly 22 million tonnes of grains on 3.1 million hectares at a yield averaging over 7 tonnes per acre. Be aware that fruit and veg require more land than corn (edible grasses) and that we grow a lot of crops we turn into alcoholic drink. So we reach a remarkable position, that:

•  In 1975 a hectare of arable plus a hectare of pasture fed 10 people

•  2005 model, 'chemical' plan;  a hectare of arable plus 1.5 hectare of pasture feeds 14 people  

•  2005 model, 'chemical vegan' plan; a hectare of arable feeds 20 people

•  2005 model, 'organic vegan' plan; a hectare of arable feeds 8 people

•   2005 model, 'organic with livestock' plan; a hectare of arable plus a hectare of pasture feeds 7.5 people

•  2005 model, 'livestock permaculture' plan; a hectare of arable plus 0.8 hectare of pasture feeds 8 people

•  2005 model, 'vegan permaculture' plan; a hectare of arable supplies 8 people.


2  Generally 1 high yielding dairy cow = 1 LU. One beef cow plus her calf to weaning = 1LU. Five ewes plus their lambs up to slaughter = 1LU. Two beef cattle in a 2 year old beef production system (1 calf to 1 year old, plus 1 1 year old to 2 year old finished animal) = 1 LU.  [2, Mark Crowe's answer] 

3 from DEFRA, 20201222, utilised agricultural area 17.3 million hectares (Mha), uncropped agricultural land increasing from 4 to 6% of the whole. Wheat production fell from 16.2 Mtonnes 2019 to 9.7 in 2020, Which was 7.0 tonnes per hectare, down from 8.4. I wonder what the usual variability is.

 Croppable land, 6.0 million hectares (Mha)

Land under horticulture (veg, fruit, glasshouses), 0.166 Mha

 Land under animals—now there's the problem, because this isn't stated clearly—is, I think, uncropped agricultural land, permanent grassland (which includes rough grazing), common rough grazing and temporary grassland. That adds up to a bit over 11Mha. Thus the total agricultural area in the UK, around 18.7Mha, has about 6Mha croppable of which about 4.5Mha is under crops at any time and around 11Mha under animals. Now, before we leap to conclusions way too soon, we should ask what we'd use rough grazing for if it wasn't animals, because this still isn't 'croppable' land. Trees, perhaps; could we turn rough grazing into usable orchard? A third of the included permanent grassland is land one might want to tramp on. These figures don't provide comparison with what we consume; they're only what is produced.

If I take the 1975 plan above, 6Mha of arable and a matching area of pasture would feed 60M people, suggesting that Britain might succeed in feeding itself, being around 10% shy of adequate. But we only use 75% of the 6Mha, which I think is crop rotation being seen. At the same time we use quite a lot of arable to grow feed for animals, but I don't see how to extract that from what I can see, but my feel is between 5 and10% of cropped land.

If we want more food grown here we need to see where we might move animal land to arable land.

Wikipedia (yes, I donated) says we use 69% of our land for agriculture and we produce 59% of what we consume. That says immediately that what we do with the land won't feed us all, as we'd need 69% * 100/59) = 117% of the land. Not all land is equal, not at all. It strikes me that we probably have quite a lot of land in the lowlands that could be diverted from cattle (and therefore into arable), but a reduction in cattle connects directly with a reduction in dairy, so one consideration is displacement, such as other milks and the land demand for that. A lot of the rough grazing is, I assume, unsuited for arable and yet usable for animals, if a lot less efficiently both in labour and animals per hectare.

4 1.7 Oilseed Rape [3]       The oilseed rape harvest has shown a decrease of 41% to just over 1.0 million tonnes in 2020. This was caused by a decrease of 28% in the planted area and a decrease in total oilseed rape yield of 17%, from 3.3 tonnes per hectare in 2019 to 2.7 tonnes per hectare in 2020. This is below the five year average. 

5 The dairy industry has become an ecological disaster. Animal agriculture is responsible for 83% of total global agricultural land, yet produces only 18% of the world’s calories. It’s a leading driver behind the destruction of tropical rainforests. And cows are huge contributors to climate change. The methane they release is 23 times more powerful than carbon dioxide in warming the atmosphere. Dairy also uses a lot of water. Factoring in the amount needed to feed and raise cows, it takes 976 gallons of water to produce one gallon of milk.

These figures are commonly quoted and it is not difficult to produce some very silly results.

We have a soy milk generator in the house. You stick the beans into the gadget (a large flask) and it grinds away to produce an acceptable milk. The residual solid matter, a pulp called okara, is something one feels there ought to be use for, since otherwise (not making milk) one would have eaten the whole bean. Manufactured soya milk sends the pulp to animal feed (hang on, I thought the idea was to reduce the animal side of agriculture); I found a few recipes, but the more I read, the more inclined I am to leave this to manufacturers to sort out. Short version; turn it into a flour or add it to the next stir-fry. Yet we never have done that and the better cook in the house is Chinese, so has grown up in a culture using soy a lot. A different site suggested simply adding the okara to your breakfast cereal; it doesn't last long in the fridge (three days) so use it or freeze it. Third site. It would be easy to think that okara ought to make tofu, but if you were making tofu then the milk would be a byproduct [step 4 of 7]. The method of making tofu ought to produce three products, soy milk, tofu and okara.

If the future of milk is plants then we need attention paid to uses of the residues (a relevant cookbook immediately wanted) and we need to see (find) costings that say this really does work, or that it is marginally more expensive now, or (and) how we're going to bridge the farmers' change period.


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