Are meat and leather production correlated?

October 9, 2009 1:29 PM

What proportion of leather comes from animals whose other parts are ultimately consumed by humans for food? What proportion of leather-bearing food animals' skins are ultimately made into leather? How would i find out?

I'd like to know how well-correlated meat and leather production are: are there leather-bearing animals whose bodies are discarded as scrap even though they could be eaten? or food-bearing animals whose skins are discarded as scrap even though they could be fashioned into clothing?

Do we (in the USA? in the world?) consume more animals for their meat or for their skins? If it's not evenly balanced, what happens to the unbalanced bits?

or am i wrong in assuming that all leather-bearing animals have flesh that could potentially be eaten for food? I'm fine with ignoring non-leather-bearing food animals for the purposes of this question.

How would i begin finding hard data on this? Comments and criticism to help me think about the question more clearly would be welcome too.

posted by dkg to science & nature (6 answers total)

There is stuff you can make from a hide that isn't leather, so that should be considered, but what the portion is or what all the uses are, I have no idea.
posted by Kid Charlemagne at 1:42 PM on October 9, 2009

I once toured a large (18,000+ head/day )pork producing facility in the States. I asked where the skins ended up, and was told their two largest customers for hog skins were pet food and football manufacturers.

How much of that translates to other species of food animal, I really have no idea.
posted by MagicEightBall at 2:08 PM on October 9, 2009

I'm loathe to say this, but I would do some of your searching in vegan and vegetarian-concerns forums for a good list of resources on this, although the bias in most of the links you'll find may be enough for you to disregard those links. I'm unsure of the ratio of meat to leather production, but as MagicEightBall said above, not all hides are used in the production of leather, although how much leather comes specifically from mutton and beef production ... no idea. I'd stay away from PeTA-related sites, though, if you don't want bias :)
According to this site, leather also comes from the dairy industry, not just the meat industry ... although that is still from a food-related industry. I'd also check this site.

Interesting Ask though, I'd love to see someone who actually knows about this give us the beef (sorry, I love puns, and doubly sorry for being useless and commenting anyway!).
posted by neewom at 2:22 PM on October 9, 2009

My NDA on this subject ended a year ago. This means, at best I'm discussing 2001 practices.
Back when I acutally used my engineering degree as an engineer I used to do contract work for the meat packing industry making robots - packing robots, sorting robots, cutting robots, slaughter robots - you name it, we tried to make a robot to do it.

From my experience with a large producer of beef related products, with a healthy cow EVERY part of the cow was used. PERIOD. If they could have bottled the "moo" they would have. If the animal had to be destroyed (disease) - NONE of the cow was used. PERIOD (total write-off).

Per cow, we get off a big chunk of the meat and pretty much the entirety of the leather. All the parts that we don't consume are either exported (eg: bull penis does infact sell in other countries) or turned into something that we will use (eg: fertilizer).

Consider this: A cow is not cheap. A cow is also big. I mean really big. A cow costs money to feed - for several years. You want as full return as possible on your investment. That means, the more of your cow a slaughterhouse can use, the more money you'll get for it.

I can't attest for sustainable farms and independent slaughterhouses. I can't attest for other leather bearing animals... I can only tell you it was an amazing (neither amazing good nor amazing bad) sight to see a days worth of work. And yes, I still eat beef.
posted by Nanukthedog at 3:32 PM on October 9, 2009 [10 favorites]

I'm a former shoemaker, shoe company executive, and shoe machinery company owner. Up until the mid-1980's, about 70% of American footwear leather demand was for cowhide, with another 10% in calfskin, another 10% in pigskin (particularly Hushpuppies and suede footwear) and the remaining 10% in goatskin (for linings) and exotic leathers (snake, iguana, lizard, alligator, bird leathers and bullhide) for fancy shoes and boots. Most of these hides (except the exotic category) were tanned mechanically using the chrome tanning process, with a smaller number reserved for vegetable tanning including specialty purpose leathers for shoe soleing by oak tanning process, and yet a smaller number oil tanned (mostly, goat and sheepskins).

Upholstery applications call for nearly 95% chrome tanned cowhide. Handbag and luggage applications are generally reserved for chrome tanned cowhide and bullhide, although, for appearance and exclusivity, some calfskin and exotic leathers are routinely used in such applications, often as trim, linings, or accent leathers. Clothing applications are largely based on chrome tanned cowhide, too, but there are specialty applications in gloves, coats and trousers for oil tanned deerskin, goat skin, and sheep skin.

Cowhide and, to a lesser extent, bullhide, are raw materials with the thickness and intrinsic collagen fiber structure to make strong, dense leather after appropriate tanning processes, for many uses, in varied industries. In fact, most cowhides, and almost all bullhides, will be so thick along the spine, that they are routinely reduced in thickness by a process called skiving, to enable their use in upholstery, luggage, clothing, and footwear applications. Pigskins, goat skins, sheep skins, and deer skins are much thinner, and have a much less dense fiber structure. It is hard to skin a pig intact, in fact, and much of the commercial product in pig skins is so thin, it can be diverted for higher value human food product in the form of fried pork rinds, which are nothing more than pig skin remnants, deep fried in lard (pork fat) until crisp, and then seasoned with salt and flavorings. Goat skin, lamb skin, sheep skin and deer skin are also, all, not dense, fibrous tissues naturally, and are most valued in applications where their supple, stretchy nature has value, as in gloves, slippers, and shoe and garment linings, as well as in chamois stock.

If you think in terms of slaughter heads, at least in the U.S., you'd think the most prevalent form of leather would be chicken leather, but of course, chicken skin is just too soft and not nearly fibrous enough to make good commercial leather. And, its value as human and animal food far exceeds its value as leather stock. Some birds, like the ostrich and emu, do yield skins with enough collagen fiber tissue to make worthwhile leather, and are highly prized, especially in footwear and luggage applications, for their unique spotted appearance (due to the quill pores), and color.

Some fish, including sharks, rays and the scaleless relatives of lungfish such as eels, can be skinned, and the skins carefully turned into specialty leather, by salt tanning or chrome tanning processes. The old salt pit methods for tanning shark skin are so incredibly malodorous, that they've ceased production entirely, except, perhaps in some tribal areas in Brazil or Africa. Seriously, the only time I smelled putrifying shark skin, in salt, in tanning pits, was a long time ago, in Brazil, and the mere memory of that horrible stench still brings sweat to my forehead, as I write this. Against that awful memory, any spray by a skunk is ambrosia, I tell you. What shark skin you can get commercially, today, is generally, politely and commercially chrome tanned, in small pieces, from frozen carcass waste.

Seal skin, walrus skin, whale skin, and dolphin leather have very small commercial markets, but of these, seal skins are still the most valued. The 2004 seal harvest was worth only $16.5 million CAD, according to Canadian authorities, however, which, on a worldwide basis, is insignificant compared to more commercial sources of skins for leather, such as cowhide.

To answer your basic question, however, the primary value for any animal, to humans, is still food. Even rattlesnakes and alligators bring more for their meat, than for their hides, hides traditionally being offal. Offal dealers well know that old offal stinks to high heaven, and is a cost to its owners, in terms of disposal. Thus, offal dealers, including those setting the markets for raw skins, are always willing to let the current crop of hides, renderings, and offal sit, against a lower price they offer. Except perhaps in exotic categories, like snake skins, and some shark and fish skins, where there is no commercial market for the meat due to foul taste or questionable palatablity, no animal is killed exclusively for its skin, so far as I am aware.

If you wear python, rattlesnake or iguana boots, or carry a baby alligator purse, like my mother had, you have a product that encapsulates one or more entire animal's commercial value. Their meat may have been given away, or consumed by the indigenous people who caught the animal, but the monetary value, in these few exotic extremes, was in the tanned skins.

Overall, such transactions represent much less than 1/2 of 1% of the worldwide leather business, in any year, I'll wager.
posted by paulsc at 7:04 PM on October 9, 2009 [19 favorites]

One category of large animal leather tannage I inadvertently left out of the above discussion was horsehide, and its genetic relatives, mulehide, donkeyhide and camelhide. Horses are no longer killed in the U.S., but horse meat is still a staple for animal feed producers, and is an excellent, tasty, fairly low fat food for humans, too, where it is legally allowed. I've eaten horsemeat on a number of occasions, including as a sandwich, in the 1980's, available from street carts in downtown Boston, on the way to Boston Red Sox games. It was very good, somewhat salty, and a bit sweeter, coaser in texture, and leaner than beef, altogether not unlike corned beef.

Raw horsehide, like cowhide, consists of a lot of thick collagen fibers, and in certain areas, such as around the base of the tail, where shell cordovan is produced, it is possible to make leather from parts of the animal that are not, strictly, skin. Tissue with high levels of collagen fiber is the main requirement for making leather. The two largest commercial markets for horsehide and cordovan leather are, respectively, baseballs and footwear.

In the past, most large mammals, including moose, elk, bear, rhino, elephants, lion, tiger, cougar, leapord, cheetah, zebra, wildebeest, springbok, gazelle, giraffe, hippopotamus, anteater, baboon, chimp, monkey, gorilla, and nutria, have all been turned, commercially, into leather products. Where human hunting pressure continues on these animals, or others, it is largely for bushmeat and trade offal (such as penises, horns, and testicles), not for skins.
posted by paulsc at 8:29 PM on October 9, 2009 [1 favorite]