Emasculating cows

Most of you probably believe in evolution, so it won’t be a huge surprise to learn that the packages of male cows and male humans are pretty similar — they’re pretty much just a bunch of squiggly cords, blood vessels, and nerves:

Image. Bull balls.
Image. Human balls.

It’s the nerves that I’m going to talk about here, since it’s the nerves that cause us to feel pain, and it’s the experience of pain that I care about when I think about castration.

Cattle feel and perceive pain in a very similar way to humans. A lot of people think that younger animals (including humans) experience less pain than older animals. It’s true that younger animals often respond differently to pain, e.g. young calves may ‘freeze’ during painful procedures, leading people to presume that they don’t really feel pain, because they’re not trying to struggle in the way that we would imagine ourselves to. There’s increasing evidence, however, that human infants and young animals do actually experience pain, (!), and that such experiences may have long-term adverse consequences, including altered neurological development and heightened pain sensitivity later in life. The Scientific Committee on Animal Health and Animal Welfare, an advisory body to the EU Commission, tells us that “very young animals feel pain and show signs of distress, and may feel pain more than adults.” No surprises to me there.

About 15 million male beef calves have their balls removed (castrated) each year in the US. We do this to improve the tenderness, level of marbling, and flavor (testosterone tastes bad) of our meat; reduce aggressiveness and sexual activity (so that they’re more ‘manageable’); and improve profits, because better meat can be sold for more money. (One downside for producers is that castrated cattle have slower growth rates and convert food to meat less efficiently).

Castration

We castrate cattle either hormonally, chemically, or physically. Physical castration involves either ‘surgically’ removing the testes (which sounds more palatable than it is) or by damaging their blood supply using a castration clamp (Burdizzo castration), rubber ring or latex band, so that they are no longer functional. The USDA reports that about 50% of US farms employ surgical castration; around 47% use rubber rings; and the rest use the clamp/Burdizzo method.

Here’s a rundown of how the physical methods work (don’t let the banality of this article’s written medium mislead you, this stuff ain’t pretty in the real world):

Surgical castration involves cutting the scrotum (testicle sack) with a scalpel blade, separating out the testes, cutting the spermatic cord and veins connecting the testicles, and then removing the testes., The scrotal incision is normally left to heal without stitches. Flies often enjoy this aspect. It’s called ‘surgical’ because it involves cutting open the body, and the use of a scalpel blade makes it sound pretty fancy. Rest assured that the picture is far less glamorous: there ain’t no surgeon involved (this is genuine cowboy stuff); it’s done out in the field, dust everywhere, no sterile prep of the wound site or instruments; often the same, increasingly blunting blade is used on multiple animals; and animals are physically restrained (e.g. on metallic boards) to prevent struggling, because no anesthetic is used. It’s colloquially known as ‘cutting’; the simplicity of this name does it little justice.

Image. Cowboy castration, cutting style.

The Burdizzo method involves crushing the spermatic cord, nerves, and vessels of each testis without breaking the skin. The clamp is held above the testicles for several seconds and may be applied twice per testicle. Like above, these guys need to be physically restrained to prevent struggling, since this stuff hurts, a lot. The ‘Burdizzo’ devices are often marketed as ‘easy’ and ‘bloodless’. These are satisfactorily misleading for the user: omitting blood does not omit the pain.

Image. A Burdizzo gets to work on a bull’s balls.

Rubber ring or latex band methods involve applying tight rings above the testicles in order to cut-off their blood flow. The testicles subsequently die from lack of blood flow, and fall off after two to four weeks. Ring and band methods may not induce signs of pain at the time of placement, however will cause a delayed response to pain due to the gradual restriction of blood flow. The band compresses blood vessels, thereby restricting blood flow and limiting the supply of oxygen and metabolic substrates to the testicular tissue, which subsequently kills cells. These tissue changes induce both acute and chronic pain, which diminish as the lesion progresses.

Image: The ring applicator, aka Extreme BDSM.

Suffice to say, all of these methods hurt — and there are lots of studies to prove it. Rubber rings are more likely to produce chronic pain compared to Burdizzo clamps and surgical castration, which are more acutely painful (as you probably guessed).

Pain

We normally assess pain using physiological, neuro-endocrinological, or behavioral studies, since, like babies, animals can’t verbalize how they’re feeling. What I’m about to outline is not the most Earth-shattering scientific discovery: behaviors that demonstrate that an animal is uncomfortable include struggling away from the procedure; head turning; and restlessness, gait and postural changes; reduced activity and increased lying down; tail flicking; kicking; eating less; and reduced interest in conspecifics or their mothers. This should sound familiar to us.

Using chemical parameters to assess pain isn’t always reliable, because chemicals are just a drop in the (bloody) ocean of an animal’s experience. For example, one study found that freshly castrated calves had similar levels of cortisol to calves that had not been castrated. However, substance P (a chemical pain transmitter) was significantly increased in calves that were castrated. Cortisol is a stress hormone used by a lot of researchers to assess pain, but a quick gut-check shows us how counter-intuitive the lack of a difference is here. This means that it’s probably not the most reliable indicator if used exclusively, and that we should be using multiple different metrics in order to develop an accurate picture of the degree of pain experienced by different procedures.

Some studies

  1. A study compared various methods of applying rubber rings by looking at plasma cortisol concentrations, response to palpation of scrotal area, time from castration until complete wound healing, and behavioral signs. The castration methods included: using a combination of a rubber ring with a Burdizzo clamp; applying one rubber ring and then surgically removing the scrotal tissue and rubber ring on day nine; applying three rubber rings placed one above the other around the scrotal neck; and just not castrating calves at all. All castrated calves had significantly more pain upon palpation than calves that had not been castrated (hooplah!), and calves that had tissue surgically removed nine days after the application of one rubber ring had markedly less pain, quickest healing time and shortest duration of chronic pain, than other castrated animals. Neither the combination of Burdizzo plus rubber ring, nor using three rubber rings placed next to each other led to an improvement compared to the traditional method.
  2. 21- to 28-week-old calves castrated with rubber ring demonstrated significantly more behavioral signs associated with pain during the first week after castration, compared to calves castrated using the Burdizzo method. These calves also exhibited signs of pain in response to scrotal palpation for up to four weeks longer than those castrated using Burdizzo clamps. Rubber ring calves also had more infection at the site of ring placement, as well as swelling and hardening of the issues.
  3. Although banding may cause less immediate discomfort than surgery, the overall impact of banding may be greater, such by reducing food intake and daily weight gain. Animals may also suffer long-term pain. For example, castration using bands lead to persistent wounds in 14-month-old bull calves castrated.

All of this pain is bad for the cows, but it is also bad for producers, since it reduces cows’ average daily gain, feed intake, and/or feed efficiency (how well cows convert their food into consumable products). This is even worse if we castrate calves later in life. Castrating at 6 to 8 months’ of age or after they have arrived at the feedlot had a a 92% increase in morbidity and a 3.5% increase in mortality compared to those castrated prior to arrival.

Alternatives

Analgesics (pain relievers) can reduce the pain associated with castration (ya think?). Using multiple types of analgesia at once, such as non-steroidal anti-inflammatories (NSAIDs) and a local anesthetic, may be more effective at mitigating pain and distress associated with castration than using one type on its own.

  1. One study found that giving analgesics after using a rubber ring or Burdizzo clamp drastically reduced pain and stress (more common sense).
  2. Animals medicated with the analgesics xylazine and flunixin meglumine during banding castration also had lower intestinal E. coli levels, indicative of stronger immunity, compared animals not given pain relief.
  3. Providing oral meloxicam (an NSAID) prior to castration reduced levels of respiratory disease in cattle in feedlots, lowering the cost associated with treatment for bovine respiratory disease and reducing the need for antibiotics.
  4. Ketoprofen (an NSAID), either alone or in conjunction with local anesthetic, can significantly reduce cortisol levels after castration. Giving ketoprofen prior to castration also increased feeding and rumination activities and elicited fewer pain-related behavioral responses in one study.
  5. Sodium salicylate (an NSAID), given either alone or along with sedation (intramuscular xylazine, ketamine, butorphanol), also significantly reduced the cortisol response when castration and dehorning were performed at the same time.
  6. Local anesthetics can also alleviate pain prior to castration. Although the injection is itself painful (these agents sting), this is minimal compared to the pain caused by castration. Injecting lidocaine into testicular tissue prior to castration with elastrator bands or rubber rings on 3-month-old calves almost abolished the cortisol response in one study, however had less of an effect when Burdizzo clamps were used, and even less of an effect with surgical castration.
  7. Other studies have found that lidocaine and bupivacaine did significantly inhibit plasma cortisol increases after Burdizzo clamp castration. The action of local anesthetics is however short-lived, and cortisol concentrations increase after the drugs after the agents have left the system.
  8. Sedating animals, such as with xylazine with or without ketamine, has been shown to reduce serum cortisol levels and behavioral indications of distress immediately after castration.
  9. Cattle can also be castrated by non-invasive means. Substances that block the release of hormones associated with sperm production can be given to achieve the same effects of conventional castration, without the associated pain and risk of surgical complications and infection. Gonadotropin releasing factor (GnRF), released by a part of the brain known as the hypothalamus, controls reproduction, and ‘immunizing’ against this hormone can reduce testosterone levels to a similar level as physically castrated animals causing infertility. These could be better options for castration of older animals, such as in feedlots, as they allow improved performance such as higher live weight, hot carcass weight, and dressing percentage, while controlling unwanted behaviors.
  10. Dare I say it, another alternative is to just not eat beef.

The American Veterinary Medical Association encourages the use of pain management techniques when performing castration. That’s what we’d hope, since they’re vets, and vets are meant to care about animals.

Having the nation’s vet body encourage pain control hasn’t really made a dent, though: most castration isn’t performed using pain relief, and it’s often (92%) combined with an equally painful procedure, horn removal to really ice the cake nicely.

Farmers are often reluctant to use pain relief because it takes more time; it costs money; some of them require veterinary administration; and doing so disrupts their work flow because they take a while to kick in.

All of these issues are only deemed prohibitive because we allow them to be. If analgesia were a legal requirement, the market would adjust just fine. Perhaps farmers could receive yet another type of subsidy to ease themselves into the transition. And/or the additional cost could be passed onto consumers, which is probably appropriate, since meat is underpriced now, anyway.

If we valued ‘production’ animals (animals that we make money from) in the same way that we valued our pets, or ourselves, we’d also require that castration be performed by a licensed veterinarian. These are highly invasive, painful procedures that, when performed on humans, puppies, or kittens, require the use of anesthesia an analgesia, and must legally be performed by a doctor. Cowboys have replaced the surgeon because we just don’t give a damn, not because the animals don’t require one.

To make things even harder, the FDA hasn’t approved the use of any drugs for pain relief in cattle. The only NSAID officially approved for use in cattle in the United States is flunixin meglumine, and even this is only approved for use in disease control, not pain relief. Flunixin meglumine must also be administered intravenously, adding to the difficulty. Extra-label use of anesthetics and analgesics is an option, but not ideal. Knowledge of their effectiveness is not as great as it is for drugs approved for particular species and purposes.

Now you know that castration is a common/necessary part of beef production; that this hurts cattle; and that that pain isn’t mitigated.

References

Scientific Committee on Animal Health and Animal Welfare (2001) The welfare of cattle kept for beef production, p. 51. http://ec.europa.eu/food/fs/sc/scah/out54_en.pdf.

Boesch, D, Steiner, A, Gygax, L, and Stauffacher, M (2008) Burdizzo castration of calves less than 1-week old with and without local anaesthesia: Short-term behavioural responses and plasma cortisol levels, Applied Animal Behaviour Science, 114:330–45.

Mellor, D and Stafford, K (1999) Assessing and minimizing the distress caused by painful husbandry procedures in ruminants, In Practice 21(8):436–46.

Puchalski, M and Hummel, P (2002) The reality of neonatal pain, Advances in Neonatal Care, 2(5):233–47.

US Department of Agriculture, National Agricultural Statistics Service: Agricultural Statistics. Available at http:/ / usda.mannlib.cornell.edu/ usda/ nass/ Catt/ / 2000s/ 2009/ Catt-07–24–2009.pdf.

Coetzee, JF, Nutsch, AL, Barbur, LA and Bradburn, RM (2010) A survey of castration methods and associated livestock management practices performed by bovine veterinarians in the United States, BMC Veterinary Research 6(12), 2009].

American Veterinary Medical Association (2011) Welfare implications of the dehorning and disbudding of cattle, https://www.avma.org/KB/Resources/Backgrounders/Pages/Welfare-Implications-of-Dehorning-and-Disbudding-Cattle.aspx, Accessed October 13 2013.

Stafford, KJ (2007) Alleviating the pain caused by the castration of cattle, The Veterinary Journal, 173:333–342.

Stafford, KJ and Mellor, DJ (2005) The welfare significance of the castration of cattle: a review, New Zealand Veterinary Journal 53(5):271–8.

Amatayakul-Chantler, S, Hoe, F, Jackson, JA, Roca, RO, Stegner, JE, King, V, Howard, R, Lopeza, and E, Walker (2013) Effects on performance and carcass and meat quality attributes following immunocastration with the gonadotropin releasing factor vaccine Bopriva or surgical castration of Bos indicus bulls raised on pasture in Brazil, Meat Science, 95(1):78–84.

American Veterinary Medical Association: Welfare implications of castration of cattle (2009), https://www.avma.org/KB/Resources/Backgrounders/Pages/castration-cattle-bgnd.aspx.

US Department of Agriculture National Animal Health Monitoring System (2008) Beef 2007–08. Part I: Reference of beef cow-calf management practices in the United States, pg 40, www.aphis.usda.gov/animal_health/nahms/beefcowcalf/downloads/beef0708/Beef0708_dr_PartI_rev.pdf, Accessed November 1 2013.

Food and Agriculture Organization of the United Nations. 1994. Chapter 3: cattle, sheep, goats and buffalo. Unit 14: castration of ruminants. In: A manual for the primary animal health care worker. www.fao.org/docrep/t0690e/t0690e05.htm#unit%2014:%20castration%20of%20ruminants.

Robertson, LS, Kent, JE, and Molony, V (1994) Effect of different methods of castration on behaviour and plasma cortisol in calves of three ages, Research in Veterinary Science, 56:8–17.

Thuer, S, Mellema, S, Doherr, MG, et al. (2007) Effect of local anaesthesia on short- and long-term pain induced by two bloodless castration methods in calves, Veterinary Journal, 173:333–342.

González, LA, Schwartzkopf-Genswein, KS, Caulkett, NA et al. (2010) Pain mitigation after band castration of beef calves and its effects on performance, behavior, Escherichia coli, and salivary cortisol, Journal of Animal Science, 88(2):802–10.

Currah, JM, Hendrick, SH and Stookey, JM (2009) The behavioral assessment and alleviation of pain associated with castration in beef calves treated with flunixin meglumine and caudal lidocaine epidural anesthesia with epinephrine, Canadian Veterinary Journal, 50(4):375–382.

Pang, WY, Earley, B, Sweeney, T and Crowe, MA (2006) Effect of carprofen administration during banding or burdizzo castration of bulls on plasma cortisol, in vitro interferon-gamma production, acute-phase proteins, feed intake, and growth, Journal of Animal Science, 84(2):351–359.

Molony, V, Kent, JE, and Robertson, IS (1995) Assessment of acute and chronic pain after different methods of castration of calves, Applied Animal Behaviour Science, 46:33–48.

Ting, STL, Earley, B, Hughes, JML, et al. (2003) Effect of ketoprofen, lidocaine local anesthesia, and combined xylazine and lidocaine caudal epidural anesthesia during castration of beef cattle on stress responses, immunity, growth, and behavior, Journal of Animal Science, 81:1281–1293.

Becker, J, Doherr, MG, Bruckmaier, RM, Bodmer, M, Zanolari, P and Steiner, A (2012) Acute and chronic pain in calves after different methods of rubber-ring castration, The Veterinary Journal, 3:380–385.

Pang, W, Earley, B, Sweeney, T et al. (2009) Temporal patterns of inflammatory gene expression in local tissues after banding or burdizzo castration in cattle, BMC Veterinary Research, 5:36.

Fisher, AD, Knight, TW, Cosgrove, GP, et al. (2001) Effects of surgical or banding castration on stress responses and behaviour of bulls, Australian Veterinary Journal, 79:279–284.

Faulkner, PM, Weary, DM (2000) Reducing pain after dehorning in dairy calves, Journal of Dairy Science, 83(9):2037–2041.

Baldridge, Sl, Coetzee, JF, Dritz, SS, et al. (2011) Pharmacokinetics and physiologic effects of intramuscularly administered xylazine hydrochloride-ketamine hydrochloride-butorphanol tartrate alone or in combination with orally administered sodium salicylate on biomarkers of pain in Holstein calves following castration and dehorning, American Journal of Veterinary Research, 72(10):1305–1317.

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Earley, B and Crowe, MA (2002) Effects of ketoprofen alone or in combination with local anesthesia during the castration of bull calves on plasma cortisol, immunological, and inflammatory responses, Journal of Animal Science, 80:1044–1052.

Amatayakul-Chantler, S, Hoe, B, Jackson, JA, Roca, RO, Stegner, JE, King, V, Howard, R, Lopez, E, Walker, J (2013) Effects on performance and carcass and meat quality attributes following immunocastration with the gonadotropin releasing factor vaccine Bopriva or surgical castration of Bos indicus bulls raised on pasture in Brazil, Meat Science, 95(1), 78–84.

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