# Why are cows magnetic? **URL:** \ **Category:** Factual Questions\ **Created:** [April 2, 2012, 4:39am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552 "2012-04-02T04:39:19Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [April 2, 2012, 4:39am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/1 "2012-04-02T04:39:19Z")
I don’t know why I never heard about this until today, but apparently the world’s pastures are being eaten alive by throngs of bovine compasses. See the [news story](https://www.npr.org/templates/story/story.php?storyId=93956323) or [study](http://www.pnas.org/content/early/2008/08/22/0803650105.abstract). All over the world, apparently cattle herds tend to orient themselves along a north-south axis. They’re even affected by magnetic declination and high-voltage power lines. I can understand the use of magnetoception in migratory species or ones that travel over long distances, but… why cows? Why?! ☹ ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [April 2, 2012, 4:47am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/2 "2012-04-02T04:47:14Z")
Mu ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [April 2, 2012, 4:48am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/3 "2012-04-02T04:48:52Z")
A 2011 followup study [debates the findings](http://www.nature.com/news/the-mystery-of-the-magnetic-cows-1.9350), but a third party commentator says that the original results, “while mysterious, still stand”. That article also contains what is now possibly my favorite phrase: “cows with unsatisfactory resolution” ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 2, 2012, 4:52am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/4 "2012-04-02T04:52:08Z")
could be interaction with the cow magnets. ---
**Author:** ![heathen\_earthling](https://avatars.discourse-cdn.com/v4/letter/h/13edae/32.png) [@heathen\_earthling](https://boards.straightdope.com/u/heathen_earthling)\ **Post date:** [April 2, 2012, 5:10am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/5 "2012-04-02T05:10:05Z")
> [@Reply](#): > > I can understand the use of magnetoception in migratory species or ones that travel over long distances, but… why cows? Why?! ☹ Some wild bovids such as the bison and wildebeest are migratory. Are domestic cattle descended from a migratory ancestor? ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [April 2, 2012, 5:14am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/6 "2012-04-02T05:14:48Z")
Modern cattle ranchers discovered a while ago that using electrified fencing and cattle prods was the most efficient way to get them to stick to the fridge. Additionally, red meat is very high in iron. ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [April 2, 2012, 5:42am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/7 "2012-04-02T05:42:00Z")
> [@](#): > > Why are cows magnetic? How attractive do you find them, exactly? ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [April 2, 2012, 5:48am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/8 "2012-04-02T05:48:52Z")
fucking cow magnets, how do they work? ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [April 2, 2012, 5:55am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/9 "2012-04-02T05:55:27Z")
I can’t stand the Insane Cow Posse. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [April 2, 2012, 6:06am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/10 "2012-04-02T06:06:49Z")
> [@heathen\_earthling](#): > > Some wild bovids such as the bison and wildebeest are migratory. Are domestic cattle descended from a migratory ancestor? [Possibly](http://www.biomedcentral.com/1471-2148/10/83); they are descended from [aurochs](http://en.wikipedia.org/wiki/Auroch). > [@](#): > > It is therefore possible that aurochsen living in several Mediterranean regions, sharing similar ecological conditions and belonging to a species with a large migratory potential, exchanged enough genetic material to maintain a certain degree of homogeneity. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [April 2, 2012, 6:08am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/11 "2012-04-02T06:08:28Z")
Growing up o our farm in west central Minnesota, the horses grazed facing south or east, mostly. But not because of a magnetic sense effect. It’s just that horses graze with their tails into the wind, and the prevailing winds on our farm were from the north or west. Possibly the same is true of cows – they tend to graze oriented based on the wind direction. And wind direction is fairly constant in most locations. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [April 2, 2012, 6:53am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/12 "2012-04-02T06:53:34Z")
Hrmm, could be something to that. [Here’s a cool “wind map”](http://hint.fm/wind/index.html) of the US that indicates wind direction from day to day. Let it load for a minute, it traces out wind currents across the map; the results are actually really cool and fascinating. Makes America look furry. ---
**Author:** ![Rachellelogram](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rachellelogram/32/8689_2.png) [@Rachellelogram](https://boards.straightdope.com/u/Rachellelogram)\ **Post date:** [April 2, 2012, 7:35am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/13 "2012-04-02T07:35:29Z")
> [@t-bonham@scc.net](#): > > Growing up o our farm in west central Minnesota, the horses grazed facing south or east, mostly. > > But not because of a magnetic sense effect. It’s just that horses graze with their tails into the wind, and the prevailing winds on our farm were from the north or west. > > Possibly the same is true of cows – they tend to graze oriented based on the wind direction. And wind direction is fairly constant in most locations. Is it so the breeze doesn’t blow their tail hair back into their butts when they poop? > [@cmyk](#): > > Hrmm, could be something to that. > > [Here’s a cool “wind map”](http://hint.fm/wind/index.html) of the US that indicates wind direction from day to day. > > Let it load for a minute, it traces out wind currents across the map; the results are actually really cool and fascinating. Makes America look furry. Hehe, there’s a [cowlick](http://i.imgur.com/v7HST.png) in Nebraska right now. ---
**Author:** ![Dervorin](https://avatars.discourse-cdn.com/v4/letter/d/eb8c5e/32.png) [@Dervorin](https://boards.straightdope.com/u/Dervorin)\ **Post date:** [April 2, 2012, 10:42am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/14 "2012-04-02T10:42:26Z")
> [@robert\_columbia](#): > > Mu _Golf clap_ I feel it deserved at least that much attention. However, the fact that there’s no element with the symbol Mu does rather spoil the joke, tragically. ---
**Author:** ![Dervorin](https://avatars.discourse-cdn.com/v4/letter/d/eb8c5e/32.png) [@Dervorin](https://boards.straightdope.com/u/Dervorin)\ **Post date:** [April 2, 2012, 10:47am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/15 "2012-04-02T10:47:43Z")
> [@robert\_columbia](#): > > Mu _Golf clap_ I feel it deserved at least that much attention. However, the fact that there’s no element with the symbol Mu does rather spoil the joke, tragically. ---
**Author:** ![asterion](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@asterion](https://boards.straightdope.com/u/asterion)\ **Post date:** [April 2, 2012, 11:37am UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/16 "2012-04-02T11:37:29Z")
> [@t-bonham@scc.net](#): > > Growing up o our farm in west central Minnesota, the horses grazed facing south or east, mostly. > > But not because of a magnetic sense effect. It’s just that horses graze with their tails into the wind, and the prevailing winds on our farm were from the north or west. > > Possibly the same is true of cows – they tend to graze oriented based on the wind direction. And wind direction is fairly constant in most locations. Instinct for protection against predators? I’d buy that. ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [April 2, 2012, 12:03pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/17 "2012-04-02T12:03:15Z")
> [@Dervorin](#): > > _Golf clap_ > > I feel it deserved at least that much attention. However, the fact that there’s no element with the symbol Mu does rather spoil the joke, tragically. Oh it was better than that - [μ](http://en.wikipedia.org/wiki/Vacuum_permeability) ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [April 2, 2012, 12:47pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/18 "2012-04-02T12:47:35Z")
Has the study taken into account that the path of the Sun is generally E-W? So if you want to be warmed up by it, it pays to have your flanks to it. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [April 2, 2012, 12:52pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/19 "2012-04-02T12:52:36Z")
> [@MrDibble](#): > > Has the study taken into account that the path of the Sun is generally E-W? So if you want to be warmed up by it, it pays to have your flanks to it. That’s what I was going to say… but then you’d expect the cows to rotate throughout the day, facing roughly N-S at sunrise, then E-W at midday (at which point the sun will be in the south, in the northern hemisphere), then back towards N-S at sunset. Of course, the sun doesn’t set due east except on the equinoxes, so the bovine angle would change through the year. ---
**Author:** ![coremelt](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@coremelt](https://boards.straightdope.com/u/coremelt)\ **Post date:** [April 2, 2012, 1:00pm UTC](https://boards.straightdope.com/t/why-are-cows-magnetic/617552/20 "2012-04-02T13:00:05Z")
> [@Der\_Trihs](#): > > [Possibly](http://www.biomedcentral.com/1471-2148/10/83); they are descended from [aurochs](http://en.wikipedia.org/wiki/Auroch). Are there any large herbivorous grazing animals in temperate climates which don’t migrate? AFAIK, the only grazing animals that don’t are either native to tropical climates that don’t have seasons or are too small to migrate. Anything that can, does, which makes sense the evolutionary pressure would have strongly favoured animals that moved north into the vast pastoral tundras in the north of europe in summer and then south into warm climates in winter. Maybe there’s no direct evidence but it seems to me pretty clear that the Aurochs would have had to migrate and so modern cows have some residual trait of a migratory urge. [Next page](https://boards.straightdope.com/t/why-are-cows-magnetic/617552.md?page=2)