When it comes to quantifying land used for either meat production or growing "plant-based foods," things can get a little messy, and I've been finding that a lot of the information that exists out there gets misinterpreted, or just outright misunderstood. Keep this quote in mind:
"There are lies, damned lies, and statistics." -- Mark Twain
No doubt there's a lot of misinformation out there on the Interweb, so much that you just have to use the DBEY(R/S)OTI method:
Don't Believe Everything You (Read/See) On The Internet!
And as someone that likes to peruse the variety of information posted on social media and websites and such, I get to come across some odd balls that makes my head cock sideways at times. Especially when I come across a few different vegan memes that have different statistics.
I have to say, before I begin, that the vegans do have it right. By that, I mean that you most definitely can and will produce a lot more "plant-based food" (i.e., vegetables, starches, fruits, and grains) on an acre of land than you can meat (be it from cattle, pigs, poultry, sheep, or goats). I am not questioning that aspect of the "meat vs. veggie" argument.
However, I have several "beefs" with this simplistic-seeming fact. Those issues I will address in the next blog post The Beef vs. Vegetable Land-Use Argument: Why It's Really a Non-Issue.
The primary talking-points I really want to address here and now are the actual statistics or numbers that vegans use to bring up the land-use vegan vs. meat argument. Not so much the discrepancies, but rather what the numbers are actually telling us.
Well, maybe more me than us, but whatever.
Two primary memes, both with their relatively inconvenient discrepancies are what I really want to focus on in this post, largely because of the difference in beef amounts per amount of land required. The third meme I'm going to talk a bit about as well is just a bit different, as it will look at the amount of land needed for a person of a particular dietary choice to live off of for an entire year.
I hope you find this interesting as I did when writing this out.
But before we begin, just let me make the note the two major factors being disregarded in both memes:
I think it's best to look at the beef side first and foremost, just to see where the number above actually stands.
As already mentioned above, time is the variable that is largely ignored. However, I tend to assume that this is based on a full year of production, or a full "growing season."
I assume these are the two sources from the meme used for their statistic on beef:
One (1) Animal Unit = One Cow-Day = One (1) 1000 lb cow or cow-calf pair consuming ~26 lb of dry matter forage per day.
(dry matter (DM) = all water removed)
Therefore, Reason 2 shows very clearly that the authors are surmising their numbers on unrealistic and extremely low forage productivity for any land base, crop or otherwise!!
So, again, take note! The SRBC article is way out to lunch and an unreliable reference for any meme, and for use in any article, blog or otherwise!!
Fortunately, the NRCS fact sheet is much, much more realistic.
Their ball park average for number of acres per year per cow-calf pair is 1.5 to 2 acres. So to convert that into cow-days per acre:
(365 days/year) ÷ (1.5 acres/year/AU) = 243 cow-days per acre
(365 days/year) ÷ (2 acres/year/AU) = 182.5 cow-days per acre
Working backwards from their pre-determined 137 lb of beef (boxed and ready to serve), and assuming that 60% of the live-weight is dressing weight, and 60% of dressing weight is boxed beef, 137 lb of boxed beef goes to (137 ÷ 0.60 =) 228.33 lb dressing weight, and 228.33 lb dressing weight goes into (228.33 ÷ 0.60 =) 380.55 lb live-weight.
Without looking deeper, sure 380.55 lb (round up to 381 lb) is quite a small animal, but we must remember that this is the amount of live-weight expected on one acre for, supposedly, an entire year.
Since we know that the finishing live-weight for cattle, depending on the frame score (see Target Slaughter Weights: Are Your Beef Cattle Fat Enough for Market), and using the standard animal unit, we can figure how many acres the meme is actually referring to.
1000 lb/AU ÷ 381 lb/acre = 2.6 acres/AU/year
What does that translate into as required cow-days per acre? Well...
365 days/year ÷ 2.6 acres/AU/year = 140.4 cow-days per acre.
If we were to use the cow-day values I calculated from the NRCS article, I can figure out how big the meme is thinking a finisher bovine *should be* according to their value of 137 lb of boxed beef derived from per acre per year.
So, funnily enough, the values from NRCS that VeganStreet sourced from actually surpasses the amount of meat that would come from one acre in a year. Not by much, of course, but significantly enough to cause anyone who hasn't even done the calculations like I did to question the validity of this meme.
The Reality of Grass-Finishing a Grass-Fed Steer
Realistically, a single steer raised for slaughter is not going to be eating the same amount of forage from the first year of purchase to the end of his life.
A young steer is purchased when he's 600 pounds. At 600 pounds he's eating about (600 lb bodyweight * (2.6% bodyweight consumed feed DM per day * 100) =) 15.6 lb of DM forage per day. As he increases in bodyweight, so the amount of feed he needs to consume will also increase. To demonstrate, if target slaughter weight is 1400 pounds, then the daily dry matter intake (DDMI) would increase for every 100 pound gain in body weight as:
700 lb * 0.026 = 18.2 lb DDMI
800 lb * 0.026 = 20.8 lb DDMI
900 lb * 0.026 = 23.4 lb DDMI
1000 lb * 0.026 = 26 lb DDMI
1100 lb * 0.026 = 28.6 lb DDMI
1200 lb * 0.026 = 31.2 lb DDMI
1300 lb * 0.026 = 33.8 lb DDMI
1400 lb * 0.026 = 36.4 lb DDMI
For a steer to get to 1400 lb in one year, he would need to have an average daily gain (ADG) of 2.2 pounds per day.
So that means that if we were to estimate how long it takes that steer to gain 100 pounds, at that rate of gain it would be about 45.5 days. From that estimate we can further estimate how much feed that steer is going to need, at 45.5 day intervals, over time.
I won't bore you with all the math. But just to demonstrate yet again, just how much feed a 600 lb steer, to get to 700 pounds, needs to eat (on a dry-matter basis) over 45.5 days, I just use this calculation:
15.6 lb DDMI * 45.5 days = 709.8 lb DM feed
If you're following along with your own calculator, you basically just need to use the same calculation for each hundred-weight increase over the 45.5 day period. Then add all those values up to get how much feed that steer will need. Here's the values that I came up with, added up to the grand total:
709.8 + 828.1 + 946.4 + 1064.7 + 1183 + 1301.3 + 1419.6 + 1537.9 + 1656.2 = 10, 647 lb total feed per year.
You're probably wondering why I'm going to all this trouble to determine how much a steer will eat over a year. Stay with me, we're getting there.
When raising cattle on grass, the important thing to remember is: Grass will grow back. It will grow back readily particularly if you are using managed rotational grazing in an area where you can get at least two or three grazing sessions per grazing season, and timing your grazing so that you are having cattle eat grass at the right time at each session.
Now, 10,647 lb of required forage per year for that bovine actually can be easily met in a good productive area that is even under 140 cow-days per acre (per the calculations derived from the meme above). An area with forage productivity of 115 to 120 cow-days per acre might be enough to meet the forage intake requirements of that steer with a year-round, management-intensive grazing (MiG) system.
And that is quite possible on one acre. Again, particularly in areas where winter is quite mild, and MiG will keep grass productive.
No kidding. By my calculations, and with the help of an Excel spreadsheet on these very calculations that I developed, a person can actually raise a single steer to 1400 lb slaughter weight on one acre that is producing 125 cow-days per acre of grass; with daily moves, a 45.5 day rest period, that steer can graze between 0.005 and 0.01 acres (= 217 to 435 square feet) of pasture land per day, with almost 3 sessions per pasture during that entire year.
And that means that, on one acre with 125 cow-days per acre of forage for that single animal, a person can get 504 lb of boxed, ready-to-eat beef on that single acre.
Pretty cool, eh? And, even with NRCS's numbers, it's not impossible to get even more pounds of boxed beef per acre; 1.5 to almost double the amount of boxed beef I calculated above!
Of course that's not saying that all areas in the world will have enough grass for to produce that amount of beef per acre, and there are other variables I didn't mention that will influence the ability to produce some grass-finished beef on one acre, but it goes to show you that you certainly can raise more beef on less amount of land than what's been conventionally thought possible. (I do believe this might be a good excuse to make another blog post about the misconception that "there's not enough land to have grass-fed cattle..." Some other time.)
Potatoes and Tomatoes: How Much Can Actually be Produced per Acre?
The easy answer is that it is highly variable. It really depends on soil type and quality, moisture, cultivars used, location, organic vs. conventional, climate/weather conditions, etc.
The meme claims that 53,000 lb of potatoes and 40,000 lb of tomatoes can be grown on an acre, assuming on an annual basis. From my research below, I've found some very different, and widely varying answers that questions the validity of the meme's claims... yet again.
For potatoes, the average yields differ quite substantially from year to year, and in different areas. Some examples I pulled from a Google search:
For tomatoes, I also found even more extreme variabilities with tomato production, with no real averages like with potatoes.
Basically, tomato growers will plant between 2,400 to 5,800 plants per acre. How much each plant will yield per growing season is variable, but most suggest to expect between 10 to 30 pounds of tomatoes per plant. Some folks are capable, if using the right varieties and ensuring good growing conditions, of 50 to 80 pounds of tomatoes per plant!!
This means, on a per acre basis, 2,400 plants on an acre may yield between 24,000 lb/acre to 192,000 lb/acre. If a person had 5,800 plants per acre, then they could expect to get between 58,000 lb/acre to 464,000 lb/acre.
Those are some significant variabilities. See Tomato Production, Hunker's Link on Tomato Production per Acre, and eXtension.org's Field Production of Organic Tomatoes for more information.
(Just as an aside, my thoughts on this "documentary" can be read HERE.)
Again, let's work with the *meat* side of this comparison first and foremost.
But first of all, the three major things wrong with using the term "meat" in this particular meme:
And I'll also tell you right now that they're talking about beef being produced from that 1.5 acres, NOT "meat." But I'll get to that after I crunch the numbers for the various animals raised for meat.
Let's just see how many animals, of each species, it takes to even make 375 lb of ready-to-cook meat:
But, before we even do that, the question we need to answer first is how much do each of these animals eat per day? Since there's always a difference in body weight, it makes life and calculations much easier if the expected amount any species of animal is going to eat is based on dry matter intake on a percent body weight basis:
Now, if we ignored the whole pasture-raised thing, and just looked at 1.5 acres as one, ginormous "factory farm," or CAFO (confined feeding animal operation), which can be easily done on 1.5 acres, we can answer Part 2 of Question 2 which I posed above regarding, "How many animals can be raised for meat per year on just 1.5 acres of land?"
As I already mentioned, the space requirements for each species is different simply because of their body size. Do you want to know what the CAFO-standard space requirements for each species actually is? Okay... be prepared to be shocked (as if the values I came up with above hadn't put you into shock therapy already...)
Therefore, all of that means the amount of animals that 1.5 acres can hold (under intensive confinement) are grossly inflated because they don't support the ability to grow feed for the animals. For most animals, more than twice the land, if not greater, will be needed to raise just a fraction of most of the animals in this list.
And that means that I'm going to ignore those values above, and only use the ones I made for raising animals on pasture to answer my third question:
"How much meat of each different listed species can actually be produced on 1.5 acres??"
Using the same dressing and and cutting percentage weights that I started off with to look at just how many animals need to be killed to produce 375 lb of meat, here are the results that I came up with:
But really, where are they coming up with 375 lb of "meat" on 1.5 acres? That's the next big question I want to answer and figure out, like with the first meme above.
I think we can all agree that it's actually based on meat from cattle, not the disingenuous term "meat" that was, in my honest opinion, stupidly used.
How Did the Makers of Meme #2 Come Up with 375 lb of BEEF on 1.5 acres??
It makes things easier when I can work backwards.
As mentioned above, I'm going to assume that 375 lb of beef is boxed beef, and not the dressed weight after slaughter. So, the actual weight of the animal is:
375 lb of boxed beef ÷ 60% retail weight from carcass weight = 625 lb ÷ 60% carcass weight from live weight = a 1041.6667 lb or ~1042 lb steer or heifer
According to Grassfed Solutions link on "Target slaughter weights: Are your beef cattle fat enough when they go to market?" a 1042 lb steer is between a frame score of 3 and 4 for steers, and 4 to 5 for heifers. This indicates the size of the steer is on the large side of "small frame" or medium-framed.
Frame scores (based on hip height in conjunction with age) range from 1 (one) to 9 (nine), with one being the smallest. Miniature cattle, I believe, could be smaller than FS-1 cattle... but let's not get into that.
Most cattle are slaughtered when they reach between 1300 and 1500 pounds. Either of these animals should yield 460 lb to 540 lb of boxed meat. And those sized-animals are large-framed animals.
But I digress.
In order to find out how to get 375 lb of beef from 1.5 acres, I need to, again, work backwards from the point of the actual live-weight of the animal so that I can ultimately find out the forage productivity of that 1.5-acre parcel. Here's basically what I did:
I know that typically the daily dry matter intake (DDMI) is 2.6% of body weight.
So, 1042 * 0.026 = 27.1 lb DM forage per day consumed.
I'm expecting about 50% utilization of a pasture (where half of the forage is eaten, the rest trampled and sodden on), and daily rotation, with 120-day rest period per paddock.
The amount of forage required per day is 27.1 lb DM ÷ 50% utilization = 54.2 lb DM per day of forage for that animal.
The number of paddocks needed is (120 days of rest + 1 day/paddock) ÷ 1 day/paddock = 121 paddocks in total.
On 1.5 acres, that means that I would probably need (1.5 acres ÷ 121 paddocks =) 0.0124 acres per paddock. Or, to do it in square footage, 1.5 acres (43,560 sq. ft./acre * 1.5 acres) = 65,340 sq. ft; Therefore 65,340 sq. ft. ÷ 121 paddocks= 540 sq. ft. per paddock.
The expected amount of forage, therefore, that a pasture is expected to produce is (54.2 ÷ 0.0124 acres per paddock =) 4371 lb/acre of forage.
That translates into... (4371 lb/acre * (50% utilization ÷ 100) / 26 lb per day daily DM intake of one Animal Unit =) 84.1 cow-days per acre.
Or, a stocking rate of... (4371 lb/acre * (50% utilization ÷ 100) / 800 lb per month DM intake of one Animal Unit =) 2.7 AUM/acre.
If I shortened up the rest period to 45 days, I would get a larger area for the animal to graze:
(45 days rest + 1 day/paddock) ÷ 1 day/paddock = 46 paddocks total
1.5 acres ÷ 46 paddocks = 0.0326 acres/paddock = 1420 sq. ft/paddock.
To the average Jane/Joe that seems like "lots of space to roam" but to me, that's too much space for just one animal to cover sufficiently in one day. If there's a lot of forage available per day, which my next calculations show that shouldn't be the case:
54.2 ÷ 0.0326 acres/paddock = 1662 lb/acre of forage that needs to be available, or 32 cow-days per acre, or 1.04 AUM/acre stocking rate.
In other words, on a really shitty pasture (pardon the pun) you can graze one 1042 lb bovine on 1.5 acres. But there's a catch.
The number of times that bovine will need to go over that pasture in a year is eight times (0.0326 acres/paddock/day * 365 days = 11.899 total acres needed for entire season (with no returning to previous paddocks grazed) ÷ 1.5 acres = 7.9 or 8 required grazing sessions for 1.5 acres in one year-long grazing season). Not all pastures are going to be that productive, especially when they have that low of forage quantity to begin with.
On the other hand, the pasture with 84 cow-days per acre will mean that it will be gone over less times over the year, make that only three grazing sessions per year (0.0124 * 365 = 4.5 ÷ 1.5 = 3 sessions for 1.5 acres in one year-long grazing season).
But the question is, are pastures only that good to graze on? My answer is look at how much a lot of hay fields can produce. You can get some that will be highly productive, as in around 4 to 5 tons per acre (or 8,816 lb/acre to 11,020 lb/acre), or more--some hay fields can get as much as 10 tons/acre (22,040 lb/acre). If a pasture can be made to be as productive or better as the average hay field (no matter if it's irrigated or not), then that means that a person can indeed raise more beef than what the meme is suggesting on one or 1.5 acres. Easily; like at least double the amount of beef than what Cowspiracy's meme is proselytizing.
So, is this second meme out to lunch? Not entirely. It's only indicative of pasture mismanagement that doesn't manage grass and animals to their full potential. It also doesn't show the huge potential that better grass management can do to actually help increase pasture productivity and thereby needing to increase the size of the herd to match that increased productivity.
Vegetable Production of Meme #2
This meme is also suggesting that a person can get 37,000 lb of so-called "plant-based food" (or rather, just food excluding meat and poultry) on 1.5 acres. That, in my mind, translates to the ability of getting 11 tons/acre of vegetables/fruit/grain etc.
Pretty ambiguous, yet again.
In the first meme above I already showed the incredible variability and discrepancies between the amount of potatoes and tomatoes--"plant-based food" essentially--that are even produced on just one acre of land. Compared to those, 37,000 lb of vegetables, fruits, and/or grains on 1.5 acres (or 11 tons/acre) is not exactly a whole lot.
Therefore this meme shows, yet again, a poor example of the potential productivity of any area of land that is even capable of being used to grow food for people.
On to the Next...
Now that I've crunched the numbers and really took a hard look at what both memes were (and were not) showing, I would like to switch gears and provide another post to explain why the land-use argument comparisons are really a non-issue, and as much of a proselytizing erroneous statement that needs to be taken with a giant grain of salt as any vegan shock-value "fact" should be regarded.
Range Nerd, Forage & Grazing Fanatic and a Bovine Enthusiast. A love for farming, and for the soil.
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