Painful Procedures and Misconceptions

by Joseph M. Stookey

Presented at the Manitoba Farm Animal Council conference "ANIMAL CARE '96: Modern Agriculture" Nov. 28,1996. Winnipeg, Manitoba.


Winnipeg, Manitoba     Whenever I reflect about animal welfare issues I am reminded that the knowledge gap about agriculture is widening between the rural community and the urban population. The vast majority of our population live, work and interact in the city on a daily basis with little or no interaction with the agricultural community. The urban population's background and their perceptions of animal welfare is different than the views held by the rural population. It is reasonable to assume that the people who work with livestock on a daily basis are more knowledgeable on the care and handling of livestock than their urban counterparts. However, it would be a mistake to disregard the concerns that have been raised by the general public, even though they may have a different knowledge base and a different perspective.

    In nearly all discussions about animal welfare, the topic of animal rights also surfaces. For most people, there is a clear distinction between the two philosophical positions. Though both positions are different, both the animal welfare and the animal rights positions are part of a continuum of philosophical approaches. Both philosophies are concerned with rights; what rights, if any, will we give our animals? The animal rights position occupies the one extreme, composed largely of vegetarians, who condemn any use of animals for human gain. Taking the philosophical continuum to an extreme, at the opposite end of the spectrum would be people who abuse animals because they believe animals have absolutely no rights. This latter extreme viewpoint has virtually no followers and is viewed by present day society as criminal. Legislation is in place to prevent abusive activities. Somewhere between the two extremes lies the welfare viewpoint. Producers, scientists and veterinarians identify themselves as welfarists and feel that their position is a "middle- of-the-road" philosophy (see Figure 1).

curve

Figure 1. Philosophical positions along a continuum of positions.

    However, since the "animal abuse" position does not exist in society, the two polar positions are reduced to the "animal rights" position and the "animal welfare" position. The majority of society may fall somewhere between these viewpoints. Overall, society agrees with the "welfare" position that we can use animals. However, the general public may also believe a portion of the "rights" agenda and launch some criticisms against current livestock systems and practices. In effect, it is the general public that occupies the "middle- of-the-road" position (see Figure 2). Both the animal rights and the animal welfare positions are more extreme than the beliefs held by the general public. From a welfare perspective there is not a more extreme philosophical position than that held by producers, scientists and veterinarians. No one is advocating that we provide less care for our animals or that we further restrict the animal's environments. This does not mean that the current position taken by producers, scientists and veterinarians is wrong or scientifically unsound. Nor does it mean that all criticisms against current production systems have merit. The illustration attempts to point out that the general public will formulate its position based on the information provided by both sides of the debate regardless of the accuracy of that information. Also, it should be realized that any changes, negotiations or concessions made as a response to concerns voiced by animal rightists or the general public will be a shift away from the present viewpoints, held by the livestock industries, towards the viewpoint held by the general public.

curve shift

Figure 2. Probable distribution of population along a continuum of philosophical positions, when there is no position more extreme than the animal welfarist.


    When agriculturists become pro-active and speak out against what we feel are unjust criticisms, we often use examples which we claim are proof of our concern for our animals. We attempt to convey the message that we are, in fact, the original animal welfare advocates since throughout our history we have tended to the animals' needs. I refer to these examples as traditional producer welfare concerns.

    All of these factors are directly related to the welfare of our animals. But it is obvious that all of these have economic importance. To stand behind these concerns as examples of our compassion for our animals will gain us little credibility and, in fact, be viewed as "protectionistic". The momentum gained by the animal rights movement in recent years is further proof that these "producer welfare concerns" are of little interest to our critics. Everyone agrees that we have made tremendous advances in the areas of genetics, nutrition, reproduction and veterinary medicine, but such advances which improve welfare are not of issue to the general public. The greatest concerns expressed by our critics are what appears to them as our overall lack of compassion for our animals through factory farming. Many people are offended by systems which deny the animals the light of day; restrict the freedom of movement; assemble large numbers of animals within a restricted area; subject the animals to routine, painful procedures; push the animals to their biological and metabolic limits; and prevent animals from expressing their normal repertoire of behaviours. If the livestock industries hope to gain credibility as welfare advocates then we must address the welfare issues that are of concern to the general public.
 

Routine Husbandry Procedures

    I would like to concentrate on some of the procedures that inflict pain upon our animals: castration, dehorning, branding, tail docking, beak trimming. There is some controversy associated with these procedures. They are controversial from the standpoint that the procedures meet with our acceptance as agriculturists versus the general public's reluctance to accept these procedures as necessary. Additionally, the public may be concerned about us performing these routine procedures without the use of anesthetics.

    Perhaps there are ways to diffuse this controversy. Perhaps there are less painful alternatives. Maybe we could discontinue some of the procedures. Or perhaps we need to promote the procedures in a positive light. Many of the procedures are done in anticipation of long term benefits to the animal (e.g. castration to reduce aggression, beak trimming in poultry and tail docking in swine to prevent cannibalism). It is true the procedures are painful, but often it is a short term pain for a long term gain. In a similar manner we know that vaccinating your child maybe painful, but we accept that the pain is worth the benefit.
 

Castration

    Whenever the topic of castration is discussed I am reminded of an old story which is retold in the opening of Bernard E. Rollin's book, "The Unheeded Cry: Animal Consciousness Animal Pain and Science". The story tells of a conversation between a young man who purchases a male camel from an old wise man.

The old wise man said, "This is a male camel.  It is a young
animal, and as it grows and gets older, this animal will get unruly.  It
would be to your advantage to castrate this male camel."
The young man asked, "How do I accomplish this, O wise one?"
The wise man replied, "You take two large stones, hold one in each hand,
place the testicles between them, and bring the stones sharply together."
"But surely this will cause severe pain", said the astonished
young man. 
"Not if you are careful to keep your thumbs out of the way",
replied the wise man.
    It's an interesting story because it captures our historical attitude about pain in animals. Historically we have not given animal pain much thought. However, the public, more than ourselves, appreciates that these are painful procedures. As caretakers we should consider addressing the issue of pain which is associated with routine animal husbandry procedures. We should review these procedures to see, 1) if the procedure is necessary, 2) if there are better alternatives and 3) if there are more appropriate times in the animal's life when the procedure should or should not be performed?

    Do we have to castrate our animals? In beef calves, the growth rate and the average daily gain is higher in bulls than it is in steers (Table 1). This is especially true if the steers are not implanted. The feed efficiency of bulls is higher as well. The carcass is leaner. And the dressing percent is even a little higher in bulls. However there are also disadvantages to raising intact bulls (Table 1). Bulls have an increased aggressive manner. This makes them more destructive on the equipment, more likely to injure each other, and people are more at risk of injury when working bulls. Also there is an increase of dark cutters if bulls are regrouped before slaughter. (Dark cutters are caused by the bulls fighting prior to slaughter, which depletes the energy and glycogen stores. This physiological change has a direct negative impact on meat quality, storage life and colour.) The hide from bulls tends to be harder to remove. The meat is leaner than steer meat, but consumer acceptance of bull meat is actually lower. In taste tests, consumers rate bull meat as less palatable.

    Aware of these negative traits the packer will discount bulls. Overall, there are some real advantages to castrating bulls and these reasons explain why castration is a routine procedure in the beef industry.
 
 

Table 1. Advantages and disadvantages of raising intact bulls versus steers.

Advantages
Disadvantages
Growth of bulls:(compared to non-implanted steers)
Traits of bulls:(compared to steers)
bulls 17% higher Ave. Daily Gain
increased aggressive manner
bulls 13% higher feed efficiency
 
Carcass traits
Carcass traits
bulls have 2% higher dressing percent
increase in dark cutters (73% increase if mixed at slaughter)
bulls are leaner (35% less fat)
hide is harder to remove
 
Consumer acceptance
 
less tender, darker and less marbling
(from Seideman et al., 1982. JAS 55:826)

Beef Castration Tools     If we are going to castrate male cattle we need to know if there is a superior method. There is a multitude of methods and tools available for castration, including: Burdizzo, Newberry knife, elastrator, emasculator and straight blade or knife. At one time there was chemical castration (no longer on the market). There have been recent attempts to immunologically castrate animals. Immunological castration attempts to vaccinate the animal against its own hormones. The releasing hormone from the hypothalamus (GNRH) is a small messenger made up of only a few proteins. This hormone travels to the pituitary and activates a cascade of events which ultimately lead to sexual maturity and fertility. In theory, if an animal could be vaccinated against its own GNRH the animal would launch an immune response against itself and produce antibodies which intercept the GNRH message and prevent it from arriving at the pituitary. In theory you could castrate the animal through injections or vaccinations. Such a procedure could eliminate a lot of the concerns about the painfulness of castration. However, immunological castration is still in the developing stages. Until such a procedure is fully developed we still have a responsibility to our animals, and to the general public, to figure out which one of the current procedures is the least painful.

    There has been considerable debate as to the least painful castration procedure. Some researchers have argued that rubber rings are more painful than surgical castration (Shutt et al, Aust. Vet. J. 1988, 65:5). From 1985 until 1993 the Canadian Veterinary Medical Association had a position statement condemning the use of rubber rings.

EZE Bloodless Castrator     The debate was revisited in 1992 after an article appeared in the Canadian Vet J. about a case of improper use of the "Eze Bloodless Castrator" on some bulls, resulting in infected animals (Can Vet J. 1992, 33:218). The device is an elastrator designed for use on larger animals. The article sparked a response by the Canadian Veterinary Medical Association and they reissued a statement against the elastrators. Following the CVMA's statement, the topic of castration and questions on which technique is least painful once again surfaced (Stookey, Can Vet J. 1992, 33:627). At least one study, in Alberta, has shown the set back in older animals was greater following surgical castration compared to animals castrated with the bloodless elastrator. This means the device maybe more humane than surgical castration when castrating older animals. The position statement against elastrators as a method of castration is no longer held by the Canadian Veterinary Medical Association because the data is so inconclusive.

    But the bigger questions here are: What age should we be castrating animals? Do we want to devise techniques to castrate adult bulls? Or should we be doing this procedure when the bull is young? Is there any evidence that says younger is better? Intact bull calves gain 5% faster from birth to weaning compared to steers castrated at birth, but implanted steer calves gain 4% faster than control steers (Bagley et al, 1989 J. Anim. Sci. 67:1258). Therefore, bull calves could be castrated at birth and implanted, which would result in nearly equal gains for implanted steers compared to bulls. The main advantage of castrating at birth would be that the healing process is so much quicker in younger animals, something we have known for quite some time (Johnstone 1944, Aust. Vet J. 20:286). Animal welfare could be advanced if the discussion shifted away from the topic of trying to decide which device is least painful and instead considered the maximum age at which castration should be performed without anesthetics. We have conclusive evidence that younger is better, from the animal's perspective.

Cattle dehorning tools     Another animal welfare concern within the cattle industry is the issue of dehorning. Like castration, there are numerous methods and tools which can be used in dehorning. The tools include: gouging devices, wire saws, caustic paste, and electric dehorners. However, we already know that the least painful and the most welfare friendly method of removing horns is through breeding. Horns can be taken off of calves by using a polled bull. Unfortunately, the dairy industry does not have access to a wide selection of polled bulls. There are very few dairy bulls listed in the sire directories that are polled. Often the polled bulls lag behind the horned bulls in production traits. Fortunately in the beef industry there is a wide selection of horned and polled bulls within many of the breeds. The beef industry does have access to bulls with the polled gene. Why then do we still have such a large number of beef calves that must be dehorned? We could leave the horn on the calves, but the amount of bruised trim off carcasses from horned cattle has been reported to be twice that from equivalent hornless groups (Meischke et al., 1974, Aust Vet J. 50:432). Why are beef producers still buying horned bulls? The obvious answer is that some producers believe the horned bulls are better than the polled bulls. However, in numerous presentations to producers, I have never encountered a single producer who can reliably distinguish horned from polled bulls when shown a photograph of a bull from the neck back. More importantly, scientific studies have not been able to detect a difference in economically important traits between polled and horned bulls within the same breed. Work done in Australia using various beef breeds (Frisch et al. 1980, Anim. Prod. 31:119) showed no differences between horned and polled crossbred lines in live weight, fertility or mortality rates. In another study there were no evidence of differences between horned and polled German Simmental cattle in growth, carcass yield, carcass composition, health and reproductive performance (Lange 1989, Ph.D. thesis). In our own work, comparing measurable traits from bulls in ROP test stations in Alberta and Saskatchewan from 1985 to 1993, we could not detect differences between horned and polled bulls in Herefords (n=1,860) or Charolais (n=578) for ADG, adjusted yearling weight, backfat thickness or scrotal circumference (Stookey and Goonewardene 1996, Can. J. Anim. Sci 75:1). As a researcher I believe it would be a waste of funding from the beef industry to compare various dehorning procedures and try to determine the least painful procedure. The beef industry can avoid the welfare controversy surrounding dehorning by switching to polled bulls. The polled gene is dominant; calves would be polled even if the cows were horned.

    Branding is another routine procedure in the beef industry which inflicts some temporary pain on the animals. The practice is widely used in western Canada and the western United States. A preliminary review of Canada's Beef Quality Assurance and Product Safety program has revealed that about 50% of all cattle slaughtered are branded and 10% of these are branded more than once (J. Van Donkersgoed, pers. comm., 1996). It has been estimated that over 95% of the cattle in western Canadian feedlots have been branded (M. Larter, 1994, President of Alberta Cattle Feeders Association). To a large extent the financial institutions have perpetuated the need for branding. Lending institutions want the animals permanently identified to insure cash receipts are returned to the lender. Ear tags and electronic identification have fallen short in terms of permanence and costs compared to branding.

    Is it possible to create a permanent visible mark without branding? We have investigated the potential of creating a permanent visible mark using depigmenting compounds. Some of these compounds were accidentally discovered to have lasting visible effects on people. Surprisingly, some of these compound produced an effect on people without causing pain at the time of contact. Though we have successfully demonstrated, in our lab, the depigmenting effects of numerous compounds when tested on cattle, we have found no compound which produced a permanent mark (Schwartzkopf et al. 1994, J. Anim. Sci. 72:1393).

    Freeze branding, which uses liquid nitrogen to super-cool the branding irons, was developed in the 60's as the "painless alternative" to hot-iron branding. Research has shown that both procedures caused physiological and behavioural responses indicative of pain (Lay et al. 1992 J. Anim. Sci. 70:1121). The response however, is short lived and does not cause a setback in gain following branding (Schwartzkopf et al., 1997 Can. J. Anim. Sci. in press). This is interesting, since most of the other routine procedures cause a measurable setback in weight gain for cattle, such as castration, dehorning, transportation, or weaning.

    Though branding must be painful there does not appear to be a lasting effect. We wondered if cattle would show aversion to reentering the facility in which branding had been performed. Such a response might be indicative of how negative the experience of branding had been on the animal. When we measured the time or reluctance to reenter the branding area we were surprised to find in our early experiments that the control animals showed equal reluctance to re-enter as the hot- iron and freeze branded groups (Schwartzkopf et al. 1997 J. Anim. Sci. in press). Further studies by our group have shown that being caught in a head gate and restrained is sufficient to masks any additional negative factors associated with branding. Branding in itself is no doubt painful and the experience may be negative, but from the animal's perspective handling and restraint are as big or bigger issues. In carefully controlled experiments we have found that a great deal of the animal's response can be influenced through habituation. The animals required longer and longer transit times as our study progressed (n=185) (Figure 3 and 4). Animals which were restrained required a significantly longer time to move through the system compared to non-restrained animals (Figure 3). However, branding caused only a small difference in the steers' response following branding on day 5 (Figure 4). Branded animals actually entered the squeeze faster than controls the day following branding, perhaps driven by some fear to get through quicker. However, the biggests and most persistent effect on transit time was due to restraint and caused by the habituation to the experiment.

graph restraint effects

 Figure 3. The impact of daily restraint on subsequent transit time of cattle through a handling facility.

graph brand effects


Figure 4. The impact of branding (on day 5 of the experiment) on subsequent transit time of cattle through the handling facility.


    Overall, the experience of branding is not as important to the animal as being caught in the headgate and restrained. I would not argue that branding is painless. We know from their immediate response that it is painful, but the fear of being handled, caught and restrained appears to have a greater influence on subsequent handling response than does branding.

    I want to switch now and talk a little bit about horses. In particular I want to discuss some of our work as it relates to equine ranchers. The information is important because the industry has come under unnecessary criticism from opponents of the pregnant mare urine industry.

    One of the areas we have been interested in researching has been to look at the incidence of stereotypies by horses kept indoors. Stereotypies are repeated, relatively invariant behaviours, that appear to serve no obvious function. For example, if you visit a zoo you may see some animals performing a particular behaviour over and over again. You may notice a bear or a tiger in an enclosure pacing the same route within its pen. Or you may notice a seal swimming the exact route within the water, with each turn and each breath of air occurring at the exact location. These repeated behaviours are classified as stereotypies and often such behaviours are performed by confined animals for hours each day. Stereotypies in zoo animals are quite common. Our domestic animals perform stereotypies too and critics of confinement systems have argued such behaviours are indicative of reduced animal welfare. Until recently most people believed that confining sows in gestation stalls caused them to perform stereotypies such as bar biting. Now we know that many oral stereotypies are due to hunger and not due to the restriction of space. Sows kept in gestation stalls are limit fed which keeps them physically fit, but the restricted feeding regime also makes them hungry. Providing sows with bulkier diets and by allowing higher level of feed intake has greatly reduced stereotypic bar biting. This is a useful finding. It means that some of the criticism against confinement is unfounded. It means that some of our understanding of the impact of housing systems on animals may have been incorrect.

    It is interesting to note that within the horse industry the PMU industry has received the bulk of the criticism from animal rightists. However, from our observations we noted very few horses in the PMU industry engaged in stereotypic behaviours. However, it is common to see horses housed at a race track performing stereotypic behaviours, such as weaving, cribbing, head bobbing, pawing and stall walking.

    Are there housing conditions, genetics, or management factors which contribute to the level of stereotypies in stabled horses? A recent study published by Paul McGreevy and coworkers from the UK (1995, Equine Vet. J. 27:86) has reported that there are management factors associated with stereotypic and redirected behaviour in horses. In McGreevy's study the risk of horses performing abnormal behaviours increased: 1) as the amount of forage fell below 6.8 kg/day, 2) when bedding types other than straw were used, 3) when the number of horses per farm was fewer than 75, 4) when the contact between horses was minimized or restricted due to stall design and 5) when good quality hay was fed rather than poor quality forage. Many of these factors seem to be related to the natural behaviour of horses. When a management factor deviated too much from the natural environment in which horses evolved the incidence of stereotypies rose. Horses are naturally social animals who spend a large portion of their day grazing and interacting with other horses. If social contact or grazing time is reduced the horse engages in abnormal or stereotypic behaviours.

    Several studies have reported on the level of stereotypic behaviours in horses. The reports range from a low of 8.1% up to 26% for stabled horses. Results from a survey we conducted with PMU producers found the incidence of stereotypies to be around 5%. We believe many of the management practices used on PMU ranches lower the incidence of stereotypies below the level found in other horse industries.

    PMU horses are typically allowed access to large amounts of forage each day and the time the mares spend eating is similar to the grazing time of feral horses. In our survey farms which fed less than 21 lb. of forage per horse per day were 2.7 times more likely to have stereotypies. The horses on all farms were meeting their daily requirement, but those farms with higher quality forage can feed smaller amounts. From the horses perspective it may be better to have lower quality forage, but more of it, than higher quality forage.

    The housing arrangement for PMU mares allows visual and tactile contact with neighboring horses, which is also a benefit for social animals. PMU horses that can touch and see each other have more social contact than horses kept in traditional box stalls.

    Somewhat surprising was the relationship between the number of times horses were watered and the level of stereotypies. If water is offered continuously to mares they develop a tendency to play in the water and create wet conditions in their stall. Therefore, producers find it better for the horses and the bedding stays drier if the water is offered several times a day instead of continuously. Some producers use watering systems that can automatically water the horses 12 or more times a day. Our analysis identified farms which watered more than 12 times per day as being 2.5 times more likely to have some horese with stereotypies. If this relationship holds up under more scientific scrutiny it may be explained again by the deviation from normal. We know PMU mares under all watering systems are receiving their daily water requirements, but it may be that water is more naturally consumed in larger amounts fewer times per day instead of smaller amounts more often throughout the day. This relationship and hypothesis have not been tested.

    It is encouraging to find the level of stereotypies among horses on PMU farms to be lower on average than the level found in other horse industries. This is a message that needs to be told. As animal welfare advocates we need to continue to work toward finding and adopting welfare friendly systems and we need to continue to educate the public and inform them of our intent and interest in our animals.

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