Well Being and Handling

Temple Grandin

Colorado State University, Fort Collins, Colorado, U.S.A.

INTRODUCTION

Reducing stress during handling for procedures such as vaccinations, milking, and herding will improve both animal welfare and productivity. Pigs and dairy cows that are afraid of people have reduced productivity. Pigs have lower weight gains and fewer piglets and dairy cows produce less milk. Fearfulness was assessed by measuring the animal's willingness to approach people. Cows on dairies where the employees had received training in stockmanship and animal behavior had a smaller flight zone and gave more milk.[1] The trained employees engaged in fewer negative interactions with the cows, such as hitting or yelling. Further studies have shown that wild, excitable cattle that become highly agitated in the squeeze chute had lower weight gains,[2] poor beef quality, and tougher meat.

squeeze chute, sweating in horses when there is little physical exertion, flapping in caged layers, and a horse rearing when he is suddenly startled. Isolation is a strong stressor, and a single cow or lamb may run into a fence or try to jump it when it is separated from its herdmates.

Physiological measures such as cortisol in the blood can also be used as indicators of fear stress that occurs during nonpainful restraint in a squeeze chute.[4] Cortisol is a time-dependent measure and it takes 10 to 20 minutes for it to reach peak levels. It is important to differentiate between fear and pain stress. Cortisol levels can also rise in response to pain from procedures such as hot iron branding. The variable of the handling stress needs to be separated from the variable of pain caused by a procedure such as castration. Handling stress is mostly fear, and stress from castration is caused by pain and injury to tissues.

BIOLOGICAL BASIS OF FEAR

Fear is a strong stressor and it can be detrimental to both productivity and welfare. People working with animals should take steps to reduce the animal's fear. Other stressors such as weather extremes often cannot be avoided, but livestock producers can easily reduce fear.

Fear is a basic emotion and it motivates animals to avoid predators. The amygdala is the brain's fear center.[3] If the amygdala is destroyed, the animal will no longer become fearful of things that would normally cause fear, such as sudden loud noise. It also loses learned fear responses. An example of a learned fear response is refusing to enter a squeeze chute for vaccinations because the cow was accidentally hit on the head by the headgate. In wild animals that are not accustomed to handling, destruction of the amygdala will make them act tame.

VARIATIONS IN HANDLING STRESS

Fear stress during handling can vary from almost none to extreme. Extensively raised cattle that were not accustomed to close contact with people had much higher cortisol levels when they were restrained in a squeeze chute compared to hand-reared dairy cattle.[5] Taming of an animal may reduce physiological reactivity of the nervous system. Hand-reared deer that were raised in close contact with people had significantly lower cortisol levels after restraint than free-range deer.[6]

There are three basic variables that will affect both the intensity of fear stress during handling and the size of the animal's flight zone. They are: 1) genetic factors; 2) amount of contact with people; and 3) previous experiences with handling that can be either aversive or nonaversive.

INDICATORS OF FEARFULNESS

One indicator of fearfulness in grazing animals is the size of the flight zone. Animals with larger flight zones are more fearful. Another indicator is the startle response to a sudden stimulus such as a firecracker. Some other behavioral indicators of fear are a cow struggling in a

GENETIC FACTORS

The domestic phenotype has reduced responses to changes in its environment.[7] Several studies have shown that there are differences in how different breeds of cattle react to handling. Brahman cattle had higher cortisol levels after restraint than crosses of the English breeds such as

Hereford or Angus. Some genetic lines of cattle, pigs, or chickens are more likely to be extremely agitated during handling.

Animals that have flighty, excitable, high-fear genetics are more likely to become highly agitated when they are suddenly placed in a new situation, compared to animals with a calmer temperament. Flighty animals have to be introduced more gradually to new things to avoid agitation and panic, compared to animals with a calmer temperament.

An experiment by Ted Friend showed that measurements of epinephrine (adrenalin) showed that some pigs habituated to a novel, nonpainful swimming task where they were suddenly placed in a pool of water. The task was repeated over a series of days. In some of the pigs, the elevated epinephrine levels returned to normal and in other individuals, the epinephrine levels remained high. Some of the pigs lost their fear of swimming and others remained scared. Genetic factors may have accounted for these differences.

EFFECT OF PREVIOUS EXPERIENCES

An animal's previous experiences with handling will affect how it will react in the future. Cattle that had been accidentally bumped on the head in a squeeze chute were more reluctant to reenter the chute a month later. Sheep that had been turned upside down in a restraint device were more reluctant to reenter the facility the following year compared to sheep that were restrained in an upright position.[8]

It is important that an animal's first experience with a new person or new place be a good one. Progressive ranchers walk cows and calves through the corrals prior to doing procedures so that they will associate corrals with being fed. Sometimes painful procedures have to be done, but it is recommended that they not be associated with the animal's first experience with either a new person or a new place. A rat experiment indicated that if a rat was shocked severely the first time it entered a new arm on a maze, it would never enter that arm again. However, if the rat was fed the first time he went into the new arm and then subjected to gradually increasing shocks, he would keep entering the arm to get the food.[9]

FEAR MEMORIES

If an animal is subjected to either a frightening or a painful experience, it may form a permanent fear memory that cannot be erased.[3] This memory is formed in the lower subcortical pathway in the brain, and extinguishing the conditioned fear is difficult because it has to be suppressed by an active learning process that requires input from higher parts of the cortex. The fear memory is suppressed by the cortex, but it can sometimes reappear. Careful, quiet handling of animals will help prevent the formation of fear memories that may compromise welfare, lower productivity, or cause behavior problems, as in horses. Animals can associate certain types of clothing or a person's voice with either a frightening or a painful experience. Animals also have the ability to recognize the voice of a familiar safe person who can calm them down.

FEAR OF NOVELTY

New experiences and new things are both scary and attractive to animals. They are attractive when the animal is allowed to voluntarily approach, but frightening when suddenly introduced.1-7-1 If a flag is placed in the middle of a large field, cattle and horses will approach it and investigate. However, if the same flag is suddenly waved next to a horse, he may become highly agitated.[7]

Animals can be trained to tolerate new things if they are gradually introduced. Cattle should become accustomed to being handled and fed by different people in different vehicles. This will help reduce stress when they are moved to a new place. Training animals to tolerate new experiences will help keep them calmer. It is important to train cattle on being moved by both people on foot and people on horses. Cattle appear to perceive a person riding a horse and a person walking on foot as two different things.

TRAIN FOR HANDLING

Training calves and pigs to handling procedures helps to produce calmer adult animals. Pigs differentiate between a person in the aisle and a person in their pens. Pigs will move more easily in and out of trucks and through chutes at a meat plant if the producer trained them by walking through their pens several times each week.

Animals will have the lowest amount of fear stress when they voluntarily cooperate with being restrained and handled. Zoos and aquariums are training animals, such as apes, lions, and dolphins, to cooperate with blood testing and veterinary procedures. Highly excitable Bongo antelope were trained to enter a box and allow blood samples to be taken when they were fed treats. Almost baseline cortisol (stress hormone) levels were obtained. The levels of glucose in the blood of trained animals was significantly lower compared to the same animal immobilized with a dart.[10]

CONCLUSIONS

Reducing fear during handling will improve animal productivity.1-1-1 There are many different stressors that animals encounter such as stimuli that evoke fear, heat stress, cold stress, pain, or fatigue. Fear is a strong stressor and it is one stressor that is easy to reduce. Fearful animals have lower productivity. Animals remember frightening or painful events and producers should be careful to avoid creation of fear memories. An animal's first experience with a new corral or person should be low stress. Training animals to handling procedures will help reduce fear stress. Both animal welfare and productivity will be improved by reducing fear stress.

ARTICLE OF FURTHER INTEREST

Animal Handling-Behavior, p. 22

REFERENCES

1. Hemsworth, P.H.; Coleman, G.J.; Barnett, J.C.; Berg, S.; Dowling, S. The effect of cognitive behavioral interven tions on the attitude and behavior of stock persons and the behavior and productivity of commercial dairy cows. J. Anim. Sci. 2002, 80, 68 78.

2. Voisinet, B.D.; Grandin, T.; Tatum, J.D.; O'Connor, S.F.; Struthers, J.J. Feedlot cattle with calm temperaments have higher daily weight gains than cattle with excitable temperaments. J. Anim. Sci. 75, 892 896.

3. LeDoux, J. The Emotional Brain; Simon and Schuster: New York, New York, 1996.

4. Grandin, T. Assessment of stress during handling and transport. J. Anim. Sci. 1997, 75, 249 257.

5. Lay, D.C.; Friend, T.H.; Bowers, C.C.; Grissom, K.K.; Jenkins, O.C. A comparative physiological and behavioral study of freeze and hot iron branding using dairy cows. J. Anim. Sci. 1992, 70, 1121 1125.

6. Hastings, B.E.; Abott, D.E.; George, L.M.; Staler, S.G. Stress Factors influencing plasma cortisol levels and adrenal weights in Chinese water deer. Res. Vet. Sci. 1992, 53, 375 380.

7. Grandin, T.; Deesing, M.J. Behavioral Genetics and Animal Science. In Genetics and the Behavior of Domestic Animals; Grandin, T., Ed.; Academic Press: San Diego, CA, 1998; 1 30.

8. Hutson, G.D. The influence of barley food rewards on sheep movement through a handling system. Appl. Anim. Behav. Sci. 1985, 14, 263 273.

9. Miller, N.E. Learning resistance to pain and fear, effects of over learning exposure and rewarded exposure in context. J. Exp. Psych. 1960, 60, 137 142.

10. Phillips, M.; Grandin, T.; Graffam, W.; Irlbeck, N.A.; Cambre, R.C. Crate conditioning of Bongo (Trage laptous eurycerus) for veterinary and husbandry proce dures at Denver Zoological Garden. Zoo. Bio. 1998, 17, 25 32.

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