| INTRODUCTION | DISCUSSION |
SHEEP AND GOATS
Harold W. Gonyou
Department of Animal Sciences
Animal Sciences Laboratory
1207 W. Gregory Drive
University of Illinois
Urbana, Illinois 61801
currently:
Research Scientist, Ethology
Prarie Swine Centre, Inc.
P.O. Box 8th Street East
Saskatoon, Saskatchewan
Canada S7H 5N9
Concern for the welfare of production animals has focused primarily on intensive confinement systems. Sheep production in the United States is relatively free from criticism because most sheep are grazed in flocks, and lambs remain with their dams for several weeks before weaning. In addition, sheep production is a relatively small segment of animal agriculture and does not attract as much attention as other animal industries.
Several sheep management procedures have been criticized, however. These include practices such as shearing, use of dogs for herding, and frequent physical handling. Castration and tail docking are procedures also used in other species, but have specific relevance to sheep in that several methods are commonly used for both of these procedures. When sheep are managed in confinement, for lambing or throughout their production cycle, problems such as mis-mothering of lambs and wool-picking may occur at a higher rate than when they are kept in more extensive systems. Raising sheep on pasture or range also draws criticism over such issues as predator control and exposure to severe weather. Many of the concerns about sheep production also apply to raising Angora goats for mohair. Dairy goats are more often subjected to restraint and confinement than sheep, and may be dehorned and de-scented.
DISCUSSION
Personnel, Equipment, and Facilities
Appropriate personnel, equipment, and facilities are essential to attain the highest standard of animal welfare in any operation. Well-trained, skillful, and conscientious personnel should be used whenever possible when handling sheep. This is particularly true for procedures such as shearing and hoof care. Novice personnel should receive training and supervision from experienced co-workers or more formally in junior college, university, or extension classes.
Part of the training of personnel should include proper care and maintenance of equipment. Wool shears, hoof trimmers, castrating tools, and other equipment should be appropriate to the task performed and in good working condition. Handling facilities should be designed for the task and species they are used for and maintained in good condition. Designs for various facilities are available from extension agents or consultants.
As with all agricultural species, welfare concerns involving sheep include topics not directly related to the on-farm production system. Transportation, marketing, preslaughter treatment, and slaughtering methods all affect an animal's welfare. Sheep are frequently involved in 4-H projects, and many fairs have sheep classes.
Sheep are also used in sheep-dog trials and shearing contests, which should have welfare supervision similar to that for fairs. Several of these topics are addressed in other fact sheets in this series.
Shearing is involved in almost all sheep and Angora goat production, including that in which the primary product is meat. Although some hair breeds of sheep do not require shearing, their productivity is such that they are usually crossed with wooled breeds to achieve a better lamb crop. Shearing is necessary for the well-being of sheep but can negatively affect the welfare of the animal if performed at an inappropriate time. Shearing when animals will be exposed to wet conditions, severe cold, or intense sunshine coupled with high temperatures can result in thermal stress. Failure to shear ewes before confinement for lambing, even in the winter, may result in moisture and health problems in the barn. Shearing itself, however, is a stress on the animal. Corticoid levels increase regardless of the method used, and it is believed the noise, heat, and contact of the clippers induce this reaction (1,2). The traditional method of up-ending sheep for shearing (resting on rump in upright position) contributes to the stress (2). Some shearers restrain sheep by binding their legs, a procedure which is stressful in itself (3) and may result in injuries, but a comparison of the overall stressfulness of this method with up-ending has not been made. Shearing is less stressful if done quickly (4), but cuts resulting from hurried or careless shearing add to stress (2).
A flock experiences more stress when approached by a person with a dog than when approached by a person alone. Driving a flock using a dog causes very high, sustained heart rates (5), indicative of fear. Dogs that bite sheep cause much greater stress than nonbiting dogs (4). However, the use of a well-trained dog does not result in high corticoid levels and probably reduces the overall stress of herding by decreasing the time required to complete the work.
Sheep may be handled several times a year for shearing, drenching, hoof-trimming, and general health inspections. Sheep are restrained during these procedures by hand or in tilt tables. Both methods are stressful (2,6,7), but no comparison of the two has been made. The stress of herding and handling can be reduced by using well-designed and well-maintained facilities (8) and conscientious personnel. Ensuring that the animals maintain visual contact with other sheep is also important to prevent excessive stress (6).
Several methods are used to castrate ram lambs (9). Surgical castration is less stressful than the use of rubber rings (10), but may represent a greater risk of infection. This risk of infection can be reduced by proper aseptic techniques. Age at castration has little effect on the lambs' response up to at least 42 days of age (10), but it is generally recommended that lambs who are several months old be castrated by burdizzo to prevent other complications. Angora goats may be left intact until they are several months old in order to obtain a muscular frame, and then should be castrated as mature sheep are. The use of a local anesthetic is suggested for surgical castration of mature animals. Many producers would prefer not to castrate their lambs in order to sustain faster and more efficient growth and avoid the stress associated with the procedure. Leaving rams intact is feasible if they are to be marketed before the subsequent breeding season. Packers prefer wethers, however, as their pelts are easier to remove (11); they discount the price of intact animals.
Tail-docking is practiced routinely on most sheep operations. Some sheep breeds have short tails that do not require docking. Docking of lambs could be avoided if the lambs' tails and hindquarters could be kept clean of feces and free from flies until marketing. As with castration, failure to perform this procedure may result in lower prices from packers. Because most lambs are exposed to flies, that they must be docked. Docking is stressful (12), but surgical removal appears to be less so than the use of rubber rings (10). There is debate over the length of tail to be left after docking. Many believe a short dock is necessary to show sheep. However, recent research indicates that short docking (½ inch) results in more rectal prolapses during the feedlot period than does long docking (3 inches) (13). Unless these results are refuted in further research, breed associations and judges should accept long docking out of humane considerations.
Lambing season is often the most intensively managed aspect of sheep production. Efforts to reduce lamb mortality may affect the welfare of individual lambs or ewes. When ewes are lambed in confinement to prevent loss of lambs to cold weather or predation, some lambs may become separated from their dams and abandoned. Proper management of the lambing barn, including provision of semi-isolated lambing sites in the pen, reduces these problems (14). Lambs born on pasture, if the weather is suitable, are less likely to be mis-mothered. An exception occurs when the flock is moved to new pasture or range and lambs become separated from their ewes during the process. This problem can be prevented by moving the flock slowly, allowing lambs to locate their dams before driving begins and keep close to them during the process. Ewes lambed indoors or in small yards are often confined to small pens with their lambs for a few hours to several days to facilitate maternal care and development of the ewe/lamb bond. Although separation from the flock is normally stressful, the post-lambing period may be an exception. A short separation is actually a normal part of parturient behavior.
Fostering lambs is a standard procedure in order to save orphaned lambs or those whose own mothers cannot produce adequate milk. The easiest type of fostering, and probably least stressful to the ewe, is fostering immediately after the recipient ewe gives birth. Since a parturient ewe is not always available when fostering needs to be performed, several other methods are also used. Under such conditions the most common type of fostering involves restraint of the ewe in a neck stanchion for several days (15,16). Other methods proven successful experimentally, but not as widely known or practiced in the sheep industry, include odor transfer using cloth jackets (17,18) or association of an odor with the odor of the ewe's own lamb (19). Of these methods, stanchion fostering involves the greatest degree and length of restraint for the ewe, but no comparison has been made to determine the least stressful system.
When intensive confinement of sheep is practiced, wool-picking may occur. Wool picking generally involves one or more sheep picking wool from a less dominant sheep. In some instances, however, a sheep may pick its own wool.
Although the stressfulness of this behavior to the recipient is unknown, it is generally felt that the occurrence of wool-picking reflects a chronic level of stress in the entire pen. Providing sufficient fiber in the diet to stimulate normal levels of rumination is considered the best preventive, but the causes of this behavior are undetermined.
The welfare concerns for Angora goats are generally very similar to those for sheep. Dairy goats are generally kept in more intensively managed and confined conditions, but appear to adapt well to frequent interactions with humans and to the restraint necessary for milking. Dairy goat kids should be disbudded (horn buds) and males deodorized at a few days of age to minimize the stressfulness of the procedures and to avoid the problems of horned adults (9). Disbudding may be accomplished by the use of either chemical or hot-iron methods using procedures similar to those used for cattle. Deodorization is accomplished by use of a hot iron. Dehorning of adult goats should be performed by or under the guidance of a veterinarian.
A number of the procedures necessary to sheep and goat production are stressful, but benefit the animals overall. Alternative methods of restraint, castration, tail-docking, and fostering are available and should be compared to determine relative stressfulness. Only a few studies of this nature have been conducted, and their results should be used in developing recommendations until additional data are available. The industry should evaluate the practice of short-docking and castration to determine if they can be eliminated or reduced through changes in industry traditions. In general, the sheep industry does not involve the more controversial welfare issues of intensive confinement. In addition, the fact that several alternative methods exist for most standard procedures would indicate that the industry has the potential to readily adapt its practices as research clarifies the welfare implications of various methods.
Burdizzo -- A device used in castration and tail-docking to destroy blood flow by crushing tissue.
Deodorization -- A procedure performed on male goats to prevent strong odors in adults. Scent glands near poll of the head are destroyed, usually when the kid is young.
Disbudding -- Destruction of the horn buds in young goat kids to prevent horn growth.
Rubber rings -- A method of castration or tail docking in which a rubber ring restricts circulation to the scrotum or tail, which leads to atrophy and falling off.
Up-ending -- Positioning a sheep so that it is supported on the ground by its rump rather than its legs. Used as a means of restraining animals during procedures such as shearing or hoof-trimming.
Wether -- A castrated male sheep.
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2. Hargreaves, A. L. and G. D. Hutson. 1990. An evaluation of the contribution of isolation, up-ending and wool removal to the stress response to shearing. Appl. Anim. Behav. Sci. 26:103-113.
3. Coppinger, T. R., J. E. Minton, P. G. Reddy, and F. Blecha. 1991. Repeated restraint and isolation stress in lambs increases pituitary-adrenal secretion and reduces cell-mediated immunity. J. Anim. Sci. 69:2808-2814.
4. Kilgour, R. and H. de Langen. 1970. Stress in sheep resulting from management practices. Proc. N. Z. Soc. Anim. Prod. 30:65-76.
5. Baldock, N. M. and R. M. Sibly. 1990. Effects of handling and transportation on the heart rate and behaviour of sheep. Appl. Anim. Behav. Sci. 28:15-39.
6. Rushen, J. 1986. Aversion of sheep to electro-immobilization and physical restraint. Appl. Anim. Behav. Sci. 15:315-324.
7. Rushen, J. 1986. Aversion of sheep to handling treatments; paired-choice studies. Appl. Anim. Behav. Sci. 16:363-370.
8. Hutson, G. D. 1980. Sheep behaviour and the design of sheep yards and shearing sheds. In: Behaviour in Relation to Reproduction, Management and Welfare of Farm Animals. Rev. Rur. Sci. 4:137-141.
9. Battaglia, R. A. and V. B. Mayrose. 1981. Handbook of Livestock Management Techniques. Burgess Publishing Company, Minneapolis.
10. Kent, J. E., V. Molony, and I. S. Robertson. 1991. Behaviour of lambs post castration and tail docking: effect of age and method. In: Applied Animal Behaviour: Past, Present and Future. Proc. Soc. Vet. Ethol., Edinburgh Univ. Fed. Anim. Welfare, Potters Bar, Great Britain.
11. Andersen, M. K., R. A. Field, M. L. Riley, R. J. McCormick, G. D. Snowder, and D. G. Bailey. 1991. Effects of age, castration, and season on difficulty of pelt removal in lambs. J. Anim. Sci. 69:3284-3291.
12. Rhodes, R. C. III, M. M. Nippo, T. J. Morgan, and W. A. Gross. 1989. Tail docking of lambs: evidence for both a long-term and short-term stress response. J. Anim. Sci 67 (Suppl. 1):99 (Abstr.).
13. Windels, H. 1990. Factors causing rectal prolapse in feedlot lambs. Sheep and Lamb Feeders Day, Univ. Minnesota 62:10-13.
14. Gonyou, H. W. and J. M. Stookey. 1985. Behavior of parturient ewes in group-lambing pens with and without cubicles. Appl. Anim. Behav. Sci. 14:163-174.
15. Price, E. O., M. Dunbar, and M. Dally. 1984. Behavior of ewes and lambs subjected to restraint fostering. J. Anim. Sci. 58:1084-1089.
16. Alexander, G. and L. R. Bradley. 1985. Fostering in sheep. IV. Use of restraint. Appl. Anim. Behav. Sci. 14:355-364.
17. Price, E. O., G. C. Dunn, J. A. Talbot, and M. R. Dally. 1984. Fostering lambs by odor transfer: the substitution experiment. J. Anim. Sci. 59:301-307.
18. Alexander, G., D. Stevens, and L. R. Bradley. 1985. Fostering sheep. I. Facilitation by the use of textile lamb coats. Appl. Anim. Behav. Sci. 14:315-334.
19. Alexander, G. and D. Stevens. 1985. Fostering in sheep. III. Facilitation by the use of odourants. Appl. Anim. Behav. Sci. 14:345-354.
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Last Modified: October 19, 2004