What happens to cows in the US?

(Larger version. Image released under a CC-BY SA 4.0 license.)

There are 92,000,000 cattle in the USA. Where do they come from, what are they used for, and what are their ultimate fates?

I started this as part of another project, and was mostly interested in what happens to the calves of dairy cows. As I worked, though, I was astonished that I couldn’t easily find this information laid out elsewhere, and decided to publish it on its own to start.

Note: Numbers are not exactly precise, and come from a combination of raw data from 2014-2016 and guesswork. Also, the relative sizes on the graph (of arrows and boxes) are not accurate – they’re hand-sized based on eyeballing the numbers and the available settings in yEd. I’m a microbiologist, not a graphic designer, what do you expect? If that upsets you, try this version, which is also under a CC-BY SA 4.0 license. If you want to make a prettier or more accurate version, knock yourself out.

There are some changes from year to year, which might account for small (<5%) discrepancies. I also tried to generalize from practices used on larger farms (e.g. <1,000 cow operations), which make up a minority of the farms, but house a majority of the cattle.

In the write-up, I try to clearly label “male cattle” and “female cattle” or “female cows” when relevant, because this confused me to no end when I was gathering data.

Let’s start with dairy cows. There are 9,267,000 female cows actively giving milk this season (“milk cows”) in the USA. For a cow to give milk, it has to be pregnant and give birth. That means that 9,267,000 calves are born to milk cows every year.

Almost half of these are female. Most milk cows are impregnated at around 2 years with artificial insemination. There’s a huge market in bull sperm, and 5% of the sperm sold in the US is sex-selected, meaning that 90% of the sperm in a given application is one sex. Dairies are mostly interested in having more female cows, so it seems like 2.25% of the milk cow calves that would have been male (because of chance) are instead female (because of this technology).

The female calves almost all go back into being milk cows. The average dairy cow has 2.4 lactation periods before she’s culled, so she breeds at a little over her replacement rate. I’m actually still not 100% certain where that 0.2-nd female calf goes, but dairies might sell extra females to be beef cattle along with the males.

The 2,755,000 milk cows that are culled each year are generally turned into lean hamburger. They’re culled because of infection or health problems, or age and declining milk volume. They’re on average around 4 years old. (Cows can live to 10 years old.)

Male calves are, contrary to some claims, almost never just left to die. The veal industry exists, in which calves are kept in conditions ranging from “not that different from your average cow’s environment” to “absolutely terrible”, and are killed young for their meat. It seems like between 450,000 and 1,000,000 calves are killed for veal each year, although that industry is shrinking. I used the 450,000 number.

Some of the male calves are kept and raised, and their sperm is used to impregnate dairy cows. This article describes an artificial insemination company, which owns “1,700 dairy and beef bulls, which produce 15 million breeding units of semen each year.” That’s about 1 in 1,000, a minuscule fraction of the male calves.

The rest of those male calves, the dairy steers, are sold as beef cattle. After veal calves, we have 3,952,000 remaining male calves to account for. They make up 14% of the beef supply of the 30,578,000 cattle slaughtered annually. From those numbers, we’d guess that 4,060,000 dairy steers are killed yearly – and that’s close enough to the above estimate that I think we’ve found all of our male calves. That’s only a fraction of the beef supply, though – we’ll now turn our attention to the beef industry.

We imported 1,980,000 cattle from Canada and Mexico in 2015, mostly for beef. We also export a few, but it’s under 100,000, so I left if off the chart.

Most beef cows are bred on calf-cow operations, which either sell the calves to feedlots or raises calves for meat directly. To replace their stock, they either keep some calves to breed more cows, or buy them from seedstock operations (which sell purebred or other specialty cattle.) Based on the fact that 30,578,000 cattle are slaughtered annually (and we know how some of them are already killed), and that cattle are being bred at the replacement rate, it seems like each year, calf-cow operations generate 21,783,000 new calves.  There’s a lot of variation in how beef cattle are raised, which I’m mowing over in this simplified graph. In general, though, they seem to be killed at between 1.5 and 3 years old.

Of course, calf-cow operations also need breeding cattle to keep the operation running, so while some of those cows are raised only for meat, some are also returned to the breeding pool. (Seedstock operations must be fairly small – under 3% of cattle in the US are purebred – so I think calf-cow operations are the majority worth examining.) Once they’re no longer productive breeders, breeding animals are also culled for beef.

This article suggests that 14-15% of cows are culled annually, I think on cow-calf operations that raise cows for slaughter themselves (although possibly only on smaller farms). If that’s the case, then each year, they must create about 14.5% more calves than are used raised only for meat. This suggests that 21,783,000 cattle born to calf-cow operations are raised for meat, and the remaining 2,759,000 calves which will go back into breeding each year. These will mostly be females – there seems to be a 1:15-25 ratio of males to females on calf-cow operations – so disproportionately more males will go directly to beef.

By adding up the bottom numbers, we get ~30,600,000 cattle slaughtered per year. In terms of doing math, this is fortunate, because we also used that number to derive some of the fractions therein. We can also add up the top numbers to get 33,030,000 born, which is confusing. If we take out the 450,000 veal calves and the 1,980,000 imported calves, it drops back to the expected value, which I think means I added something together incorrectly. While I’m going to claim this chart and these figures are mostly right, please do let me know if you see holes in the math. I’m sure they’re there.

“Wow, Georgia, I’m surprised, I really thought this was going to veer off into the ethics of the dairy industry or something.”

Ha ha. Wait for Part 2.

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