I find that factory farming apologists are probably the biggest masters of sophism. By that I mean being able to produce wrong arguments that will nevertheless cause most of the people, even intelligent people, to shut up. Here I explain why three of their arguments are wrong.

1. The high-fiber grains that cows eat causes much less soil depletion that the grain humans eat.
   Now, we all see that grass grows where most other plants cannot grow, and we know that grass is full of cellulose. So it's easy to make a wrong induction that plants which are higher in cellulose are somehow less demanding of land than plants high in starch. Well, that doesn't work that way. Soil depletion has to do with protein (the nitrogen), and not with carbohydrates. Carbohydrates in plants come from air, not from the ground. They are created from CO₂ in air via the photosynthesis.
   The fact that having a billion of grain-fed cows damages our food security should be obvious. But, as usual, you can make things more complicated by making unfounded assertions.
2. Grass-fed cows emit around 3 times as much methane per a litre of milk than grain-fed cows. That is evidenced by the fact that our methane emissions reached their peak in 1980s, the time when the number of grass-fed cows was at its highest, and have been falling sharply ever since.
   That argument is usually accompanied by this diagram, or a similar diagram:
   
   Pay attention to the first derivative of the curve. The rate at which that curve grows is very fast in the 1980s and it quickly becomes less and less steep the more right you go. That must mean that our methane emissions reached their peak in the 1980s and have been rapidly decreasing since. Seems reasonable, right? Well, it isn't. In fact, as counter-intuitive as that might sound, this curve is almost exactly what we would expect to see if our methane emissions were constant. It has to do with the fact that methane we emit doesn't stay in the atmosphere forever, but it interacts with the ozone to produce carbon dioxyde and water, and its amount decreases exponentially with a half-life somewhere between 9 years and 12 years. At the first sight, that fact doesn't change much, but let's try making a computer simulation. The transfer function is: . I think the most intuitive way of getting to that transfer function is via the impulse response (Remember that, for linear time-invariant systems, transfer function is equal to the Laplace transform of the impulse response.). Then you can get the z-transform via the bilinear tranform. And then there is quite an obvious way to approximate our methane emissions using the Gauss'es Method of Elimination taught in the Linear Algebra classes, and you can improve that approximation using a simple genetic algorithm. If you set the half-life of the methane to be 12 years, you get this:
   
   Only a slight downward trend, not nearly as much as looking at the first derivative would suggest. And if you assume the half-life of the methane in the atmosphere is 9 years:
   
   No discernable trend here, either upward or downward, right? I've written a Word document about it in the Croatian language, in case you want to learn more. I shall warn you, it is pretty technical.
   What's interesting about this argument is that it makes use of what people are taught at the university about mathematics. At the university, we are encouraged to try to estimate the derivatives of the curves as if that will tell us something about those curves. In this case, it just misleads us. Similarly, in our cybernetics classes, we are taught that if something is "slightly less than an integral", it's probably an IT₁-type system, and that is again building a bad intuition for this case.
   And that figure of 300% difference in methane emissions between grass-fed cows and grain-fed cows comes from the assumption that cow's methane emissions are approximately proportional to its cellulose intake. Since grass contains much more cellulose than grain does, and feed-conversion-ration is much higher for grass-fed cows than for grain-fed cows, it's easy to see why the estimate is so high. However, it's probably wildly incorrect for two reasons:
   1. The assumption that cows don't emit methane while digesting starch is not correct.
   2. Pastures contain aerobic methanotrophic bacteria absorbing much of the methane that a cow on a pasture emits.
   That's why peer-reviewed studies generally put the number to be around 20%, rather than 300%.
   And even if that argument were true, would attempting to curb climate change by increasing the chance of a pandemic of superbacteria (as grain-fed cows are, well, factory farmed cows, given a lot of antibiotics) make sense? I don't think so.
3. Capitalism makes sure the lives of the farmed animals get better and better, because the factory farms are competing with one another.
   Yes, factory farms are competing with one another. However, do the animals get to choose which factory farm they belong to? No? Then there is little or no incentive to make the lives of the animals better. And indeed, 100 years ago, an average cow lived for 20 years, now she lives for 6 years. And an average chicken lived for years, now she lives for mere months.

The usual methods for detecting pseudoscience don't work here. In my recent blog-post, I argued that Flat-Earthism can easily be detected as pseudoscience because the vast majority of their arguments are not even wrong: if you ask them "And how does the Flat-Earth Theory explain that phenomenon?", you will not get a coherent response. That tactic doesn't work here. For the second argument, you probably need to make a computer simulation to fully understand why it doesn't work. Not many people are capable of doing that.

UPDATE on 15/02/2025: If you will spread this word on Internet forums, prepare to be hated, even among the people who claim to care about animal rights and public health. I got banned from PhilosophicalVegan for a year and a half for making a thread about why the second argument is flawed. That is confusing. I expected that they would probably end up praising my effort to apply what we were taught in our cybernetics classes to something from the real world. I can only speculate about the reasons why that wasn't the case. I think the right question to ask is: "Why do people hate you for stating the obvious fact that eating eggs is more immoral than eating meat?". And I guess there are three reasons. First, eating meat sounds barbaric, because somebody needs to die for us to eat meat. It seems less wrong to eat eggs because, well, egg is not a bird, and nobody needs to die for us to eat eggs. But once you look at the actual public health (superbacteria) and animal suffering consequences of eating eggs and eating meat, it seems obvious that eating eggs is worse. Second, most vegetarians are political left-wingers, and saying that eating eggs is immoral sounds like you are being against abortion rights. Of course, those are entirely different things, but not many people are rational enough to realize that. Third, it's easier to empathize with cows and pigs than with chickens. There is this idea in many people's heads that birds are less sentient than mammals because of having a smaller brain. That belief is, of course, incompatible with modern science, as birds have a more efficient brain structure than mammals do, but the belief still prevails. So, yeah, don't say I didn't warn you that you will be hated for spreading this information!