Commercial rabbit production includes the production of meat, pelts, and wool and the production of live animals for breeding and laboratory stock and for pets.
In the United States, a large number of people involved with rabbits are fanciers-- people who raise rabbits for show purposes. Although this group may not directly seek advice from an Extension agent, they may serve as a source of information and assistance. The American Rabbit Breeders Association, Inc., is one group that deals with many aspects of rabbit production. They set standards of perfection for judging and sponsor a variety of events for rabbit enthusiasts. The Professional Rabbit Meat Association is comprised of rabbit growers producing rabbits for meat and sponsor a newsletter and computer network to provide mutual assistance.
The "Easter Bunny Syndrome" makes commercial rabbit producers particularly vulnerable to criticism. Rabbits are naturally "cute" and possess physical attributes that attract the affection of most people. The production of rabbits as a source of fur has been addressed by animal protection groups (People for the Ethical Treatment of Animals and other groups).
As animal protection actions and concerns continue to rise with regard to the acceptability of standard husbandry practices, people involved in the production and use of rabbits need to be aware of potential problem areas. Several commercial production practices may be targeted as welfare concerns:
Confinement Rearing
Controversy over the confinement rearing of social species of livestock (calves, poultry, swine) has been a primary welfare issue. Although little attention has been focused on rabbits, it is reasonable to assume that the same complaints of space restriction and social deprivation are tenable. Rabbits are usually caged in groups before sexual maturity and individually as adults. Most fryers (young rabbits harvested for meat), are group-raised littermates. Fryers are marketed at a target age of 56 days but may not attain market weight until 70 days. Commercial rabbit producers house rabbits in caging systems with cage sizes adjusted for breed of rabbit, management system, and intended purpose (e.g., breeding adults vs. laboratory stock). Because of the ventilation problems inherent in multi-deck caging systems, most large rabbitries have a single deck of cages. In the U.S., water is usually provided by an automatic watering system, and food is hand-distributed to each cage (Cheeke, 1987; McNitt, et al., 2000).
Possible welfare concerns may include social deprivation (in the case of singly housed adult breeders), cage sizes and floor types, and stocking densities of group-raised market animals. Adult rabbits generally are not housed in groups. Because of the rabbit's territorial nature, each cage is regarded as an individual's own territory by both sexes. Scent marking occurs, and if other rabbits are introduced, fighting is prevalent (Harkness, 1988; Lukefahr, et al., 2004). Studies have been undertaken in Europe to develop housing systems for breeding groups (Stauffacher, 1986; Dal Bosco, et al., 2004). A 3-year study in Canada indicated that rabbits could be successfully group housed on the floor in a facility with smooth concrete floors and epoxy-treated block walls. The rabbits were grouped at 8 to 9 weeks of age. Grouping older rabbits required the use of tranquilizers or castration to avoid fighting (Love and Hammond, 1991). A New Zealand study reported that group-housed does have a significantly lower proportion of young alive at 21 days postpartum than does individually housed in boxes (Muller and Brummer, 1991). However, further study is needed to assess whether well-being is compromised for certain group members and the overall impact on production.
Work has been carried out to determine the effects of environmental enrichment on rabbit performance. This generally has been positive and enrichment objects introduced into the cages have caused stimulation and increased activity (Huls, et al., 1991; Brooks, et al., 1993; Lopez, et al., 2004; Verga, et al., 2004) but enrichment has not been shown to affect performance (Maertens, et al., 2004; Verga, et al., 2004) although enrichment objects may increase mortality (Mirabito, et al., 2000). Enrichment objects have included wooden dowels, wooden rings, a brass wire ball, hay or straw and empty aluminum beverage cans. Huls, et al. (1991) and Brooks, et al. (1993) provided PVC "tunnels" between two cages so the adult female rabbits could be apart or together. Given such a choice, the rabbits spent 90% of their time together. Finzi, et al. (2000) housed rabbits in units that provided the choice of an exposed cage, an underground cage, or the tube connecting the two. There were no differences in preference among areas and the behavior was not affected by season or reproductive status. Orova, et al. (2004) found that growing rabbits preferred wire net floors rather than deep litter at normal temperatures (16-18EC). A two tier cage provides spatial enrichment without increasing floor space requirement (Finzi, et al., 1996). Margait and Finzi (2000) reported that most of the feeding and drinking occurred on the lower level but there was no statistically significant difference because of the large variation among does.
Studies have also shown that environmental enrichment has great psychological benefits, especially for singly housed animals (Lidfors, 1997). The provision of shelves or boxes to give an area of raised height seems to be particularly beneficial (Hansen, 2000; Gerson, 2000). The provision of hay has both behavioral (Berthelsen, 1999) and health benefits (see below).
In market rabbits, stocking densities have been studied to determine the effect of rabbit density on growth and consumption parameters. High stocking densities may result in rabbits reaching slaughter weights 3 to 5 days later than rabbits housed at lower densities (Maertens and DeGroote, 1984). Singly housed control animals reached slaughter weight an average of 1 week earlier than group-raised rabbits. Fur-plucking and ear-biting were behavioral manifestations attributed to overcrowding. Several studies showed no consistent difference in rate of gain, feed efficiency, and mortality when rabbits were stocked at densities of 930, 465, and 310 cm2 per rabbit in either conventional or large pens (Lukefahr, et al., 1980; Harris, et al., 1981; Prawirodigdo, et al., 1985). Hamilton and Lukefahr (1993) found no significant mean differences in feed intake, feed efficiency, survival rate and uniformity of final weight for rabbits housed at 929, 465 or 310 cm2 per rabbit although the rabbits in the first group had better numerical means for all four traits.
European studies have produced similar results. One study found that 500 cm2 per animal gave the best overall performance results (Ferriera, 1984), while another reported that densities of 583 and 700 cm2 per animal were detrimental (Petersen, et al., 1988). Studies in France have indicated that there are reduced social interactions and locomotory activities with less than about 650 cm2 per animal. It was reported however that even at high densities aggressive encounters were uncommon and mixed sex housing did not result in major problems (Morisse and Maurice, 1996). Similarly, Bell and Bray (1984) found that the sex composition of rearing groups had little effect on weight gain, feed intake or mortality from 30-93 days of age. The incidence of injuries in male rabbits 60 to 80 days of age increased significantly as the size of the group increased from 15 or less to 16-30 or over 40 animals (Bigler and Ester, 1996).
Matics, et al. (2004b) reported that younger rabbits prefer a higher density and, given a choice, will select a more densely occupied area. This has led to the suggestion that younger rabbits (21-42 d) should be housed at a high density and then at a lower density for the finishing period (Matics, et al., 2004a). This housing method reduced mortality among the rabbits (Rashwan, et al., 2004).
In recent years, advocacy of "free-range" systems as an alternative to confinement rearing has become a popular topic in the animal welfare and sustainable agriculture arenas. Some concern has also been raised that wire floors are not a suitable substrate for rabbits and may result in increased incidence of ulcerative pododermatitis (sore hocks) (Drescher, 1992; Drescher and Schlender-Bobbis, 1996). Rommers and Meijerhof (1996) compared several alternative floors for cages. These included slats and several configurations of synthetic meshes. Most resulted in less footpad injuries than wire floors but did not influence the production of the does. Trocino, et al. (2004) found that there was no difference in production rates of rabbits on slatted or wire net floors. Because of the increased expense of the alternative floors, production costs were increased and profits reduced. A study that compared cage-reared to floor-reared meat rabbits found that production performance of rabbits was similar between the two housing systems up to 70 days of age. After 70 days, stocking density became an important factor (Crimella, et al., 1988). Lambertini, et al. (2001) and Metzger, et al. (2003) found that mortality was higher for rabbits reared on litter and that the caged rabbits had higher weight gain, feed efficiency, carcass weight and dressing percentage. A concern is the spread of coccidiosis in floor-reared rabbits.
Finishing fryer rabbits in pens on grass that were moved to a new site each day resulted in slower growth rates and lower carcass and kidney fat weights and required more labor than rabbits finished in cages. This system might be profitable in those cases where the consumer is willing to pay extra for a grass finished product (McNitt, et al., 2003).
Future research that focuses on different production philosophies and their companion systems can help to elucidate the benefits of each system to both humans and animals (Harkness, 1988; Lukefahr, et al., 2004).
Post-Partum Breeding
Post-partum breeding is a common practice among rabbit producers in Europe (Camps, 1983). After kindling, does are re-bred within 48 hours. This practice has been condemned by animal protection groups despite the fact that wild rabbits re-breed in the same manner (Lockley, 1954; Harkness, 1988). One British publication does not recommend re-breeding until 3 to 7 days post-partum on welfare grounds (King, 1988). In the United States the majority of producers re-breed at 14 or 35 days post-partum. There is no direct advantage in re-breeding at 1 day versus 14 days post-partum in terms of the total number of kits weaned (Harris, et al., 1982).
Wool Harvesting
Wool harvesting practices also have the potential to become an issue. Angora rabbits grow a low-density fine fiber that produces light-weight warm garments. Wool harvesting can be accomplished by shearing or plucking (Schlolaut, 1987; Kilfoyle and Samson, 1988). Some countries have banned the plucking of wool on the grounds of cruelty. Plucking, when done properly, involves the testing and removal of loose hair, preferably during molt. However, some types of Angora rabbits (e.g., German Angora) do not molt readily and should not be plucked (McNitt, et al., 2000). Theoretically, plucking removes only the longest fibers and leaves the undercoat to protect the rabbit. It does, however, damage the follicles and change the composition of the coat, thereby reducing the lifetime wool yield (Schlolaut, 1987; Kilfoyle and Samson, 1988).
Shearing is more widely practiced in the United States. Proper handling and methods of restraint should be utilized to ensure protection from nicks and cuts during the process. Other welfare considerations include protection from temperature extremes. Rabbits should have from 1/4 to 1/2 inch of wool left on the body and should not be sheared or plucked during particularly cold months. When temperatures drop to 35oF or less, rabbits should be provided with warm quarters and a nest box until the wool has reached at least 1 inch in length (Vermorel, 1988; Vernet, 1988).
Fur Production
The fur industry has been under attack by animal activists for several years, with a dramatic escalation in the past 5 years. Ethical and welfare arguments have been advanced with regard to the necessity for fur garments and the methods used to capture wild fur-bearing animals or to produce and euthanize ranched species (Nilsson, et al., 1980; Commission of the European Communities, 1991). In the United States, few rabbits are commercially grown specifically for their pelts. Most rabbits raised for pelts are of the Rex breed (McNitt, 1988). In the Rex pelt, the guard hairs and underfur are of the same approximate length. This provides a dense, even pelt useful for garment manufacture. The monetary value, however, is not sufficiently high and is generally not a profitable enterprise (McNitt, et al., 2000). Unlike other species of ranched fur-bearers where the pelt is the only product produced, the rabbit carcass can be used for meat. Although this is of little comfort to activists, the general public may be more accepting of the use of the entire animal, rather than killing for just the hide.
Transport
The transport of rabbits to processing facilities can pose welfare questions similar to those raised for other livestock species. Separation, caging, crating and handling practices, mixing, food and water deprivation, noise, temperature, humidity, and other environmental changes are all variables that affect the physical and psychological welfare of animals. Transport has been shown to affect meat in rabbits by increasing the rate of muscle glycogen depletion, which causes dark, firm, dry meat; increasing plasma glucose; increasing liver glycogen (during long hauls); and decreasing liver weights (Jolley, 1990). Having water available reduces live weight and carcass losses associated with antemortem handling (Coppings, et al., 1989). Factors that may affect the transport stress include the type of housing with penned rabbits coping better than caged rabbits (Canali, et al., 2000), sex with females suffering more shrink than males (Trocino, et al., 2003), and transport distance. Longer distances resulted in higher muscle pH, redder carcasses, higher muscle moisture and drip loss, higher water holding capacity and higher shear force (Dal Bosco, et al., 1997). More research is needed to elucidate transport stressors and to recommend improvements. In the meantime, humane handling and hauling practices should be encouraged and practiced.
Slaughter
Humane slaughter has been and will continue to be a concern of both animal user and animal protection groups. Unlike other farm livestock, rabbits are not covered by the Humane Slaughter Act (Anon., 1906); however, interest is high in securing more humane methods for stunning (Anon., 1992). Rabbits that are processed in commercial facilities undergo electrical stunning, which renders the animal unconscious, and then are decapitated. To achieve a suitable level of stunning, a minimum stunning current of 140 mA at 100 V should be used (Anil, et al., 1996). In smaller processing facilities or on-site slaughter, however, manual methods are used. Two methods have been recommended for manual stunning (Arrington and Kelly, 1976; Sandford, 1986; McNitt, et al., 2000). The first method is cervical dislocation. When performed by a competent person, cervical dislocation renders the rabbit unconscious immediately. The second method involves the use of a blunt stick to strike the rabbit behind the ears at the base of the skull. Generally, cervical dislocation is the preferred method for manual stunning. Welfare problems arise when inexperienced personnel attempt to perform the stunning. Care should be taken to properly train personnel before they attempt to manually stun a rabbit. Trainees should learn the proper way to handle the rabbit to reduce excitability and stress; observe the technique being performed by a competent individual; and perform the technique under supervision until competence is attained.
Sales
There is a real possibility for problems for producers who rear rabbits for sale to laboratories for use in consumer product testing. Consumer product testing procedures that specifically use rabbits, such as the Draize eye irritancy test, have been major animal welfare and rights issues for a number of years. Another important consideration for producers who sell stock for purposes other than food or fiber is compliance with U.S. Department of Agriculture (USDA) regulations under the Animal Welfare Act. Rabbit producers who sell to buyers other than processors or individuals purchasing the rabbits for their own use must be licensed by USDA if their gross sales exceed $500 per year (USDA, 1990). USDA sets facility standards, specifies the management practices that must be followed, and inspects facilities to assure compliance. Public complaints about producers are directed to USDA for consideration. Pet stores, carnivals, and other animal sellers or exhibitors often purchase stock from unlicensed producers because of lower prices. This practice should be discouraged, because it discriminates against licensed producers and leaves the industry open to criticism for non-compliance with the Animal Welfare Act.
Conclusion
Ultimately, it is up to rabbit producers to ensure that they provide for the needs of their rabbits. Proper housing, appropriate and adequate feed, ventilation, clean water, health management, and environments designed to decrease stress are all important contributors to rabbit well-being. Research is needed to further determine factors that contribute to both physiological and psychological well-being of domestic rabbits.
References
Anil, M.H., Raj A.B. Mohan and J.L. McKinstry. (1996). Evaluation of electrical stunning in commercial rabbits. Proceedings of the 6th World Rabbit Congress (Toulouse) 2: 407-415Additional information may be obtained from:
American Rabbit Breeders Association