Housing and welfare of growing rabbits. Part II – Enrichment

Zsolt Szendrő

Zsolt Szendrő

Hungarian University of Agricultural and Life Sciences, Kaposvár Campus, 7400 Kaposvár Guba Sándor str. 40, Hungary

Professor Dr. Zsolt Szendrő is a senior scientist at the Hungarian University of Agriculture and Life Sciences Kaposvár Campus (formerly Kaposvár University). His research activity is related to small animal breeding, primarily to rabbit breeding.

He was elected as the vice-president of the World Rabbit Science Association three times, so he held this position for 12 years.

He was also elected as a member of the Hungarian Academy of Sciences. He published nearly 250 scientific papers, which resulted more than 4,000 independent citations.

ABSTRACT

Conventional housing systems for rabbits provide feed and water but do not offer further installations for occupation. Recent development in regulations for commercial rabbit production consider environment enrichment as essential for the expression of the full behavioural repertoire of the animals and their welfare.

Research on enrichment of rabbits housing has been focused on various forms of elevated platforms and gnawing objects, such as wooden sticks or hay blocks. Elevated platforms are preferred sites for resting in cages and pens.

The platforms are especially attractive for the rabbits, when they are covered with a ceiling. In open pens the rabbits prefer to sit underneath the platform. Platforms may be used to offer different floor types, such as wire netting or perforated plastic floor.

There is no negative effect of platforms on performance. The effect of elevated platforms on welfare-related behaviours is not clear. Rabbits prefer gnawing sticks made of soft wood, such as linden.

Gnawing sticks are intensively used when fixed on a wall. There was no effect of wooden sticks on performance criteria, but positive results are shown with regard to aggressive behaviour, fear and ear injuries.

The consumption of hay or hay blocks as gnawing material leads to reduced growth.

Environmental enrichment increases the cost of production and increases the prices for rabbit meat.

INTRODUCTION

Part I of the article is dealing with the different housing systems and their main characteristics, such as group size, space and floor type.

Enrichment devices are assumed to improve the animal welfare through more options to move and to increase the behavioural repertoire (Verga et al., 2009). There is increasing interest to study the effect of environmental enrichments on production and welfare criteria.

ELEVATED PLATFORMS

Elevated platforms increase the living area for growing rabbits inside the cages/pens, giving them greater freedom of movement in three dimensions, which is beneficial from the animal welfare point of view.

According to Postollec et al. (2008) elevated platforms in large pens are utilized for exercise. Greater movement possibility provided by platforms in cages and pens, have no significant influence on productive performance (Krunt et al., 2020).

Matics et al. (2014) compared cage housing (2 rabbits/cage) or pen housing (14 rabbits/pen) without and with platforms.

Feed intake, weight gain and body weight decreased only when platforms in pens were presented with deep litter. Differences in feed conversion ratio and mortality were not statistically significant.

Place preference of growing rabbits was examined in pens with wire-mesh or deep litter platforms (Figure 1).

The frequency of staying on or under the platform, and in the feeder and drinker area was studied (Szendrő et al., 2012).

Figure 1.
Experimental pens with wire-mesh and deep litter platforms.

In the case of the deep litter platform, rabbits were mostly observed underneath the platform while they preferred to stay on top of the wire platform (Figure 2).

The avoidance of the deep litter platform may be explained by problems of heat dissipation on the straw bedding and the preference for hidden places.

The avoidance of the area underneath the wire platform may be caused by prevention of urine excreted by pen mates on the platform. Installing a manure pan under the wire-mesh platform improved the acceptance of this area.

Figure 2.
Location preference of growing rabbits in pens with deep litter or wire mesh platform (Under: under the platform, F & D: at the feeder and drinker, On: on the platform) (Szendrő et al, 2012).

Farkas et al. (2016) examined production, mortality, number of injuries and stress hormone levels of growing rabbits in pens (1.86 m²) with no elevated platform or two-level platforms made of wire-mesh or plastic-mesh (Figure 3).

There were no significant differences between the groups for the production traits. Authors also examined the location preference of rabbits (Matics et al., 2018).

Based on the floor area of the cage without platforms, the stocking density was 16 rabbits/m2. For comparability, the number of rabbits was calculated per m² floor/platform area.

The highest density was on the wire-mesh floor, in front of the platforms (15.7 and 13.3 rabbits/m2 in pens with wire-mesh and plastic-mesh platform, respectively) and under the platforms (9.8 and 8.3 rabbits/m², respectively).

There were fewer rabbits on the platform than on the floor: 2.7 and 5.8 rabbits/m² on the first level (7.8 and 9.1 rabbits/m2 on the second level, respectively).

The choice of the area under the platforms (including the first level) may have been influenced by the fact that the rabbits on top could urinate on the pen mates below. At the same time, there were more rabbits on the plastic mesh than on the wire mesh platforms.

Figure 3.
Pen with two-level elevated platforms.

Lang and Hoy (2011) compared pens with and without elevated platforms. No difference was found in weight gain and body weight between the two groups. Percentage of body lesions was the same in pens with and without elevated platforms (26.4 and 28.5%, respectively).

They observed that at a younger age, the growing rabbits stayed more often on the platform in the dark period and more frequently under the platform in the light period. In the experiment of Trocino et al. (2019) the rabbits spent 20.6% of the time on the platform and 29.4% under the platform.

Trocino et al. (2018, 2019) observed a higher incidence of lesions associated to aggression in pens with elevated platforms (20.6%) than in pens without platform (11.7%). Significant differences were found in some other behavioural patterns.

A longer time resting in stretched position and biting or licking the pen elements in pens with platforms were observed compared to those without. At the same time, the time of drinking, allo-grooming and moving were lower in pens with elevated platforms.

Environmental enrichment

Hay, straw or gnawing sticks are most often given to growing rabbits. Among different environmental enrichments, gnawing objects have been tested (Hansen and Berthelsen, 2000; Luzi et al., 2003; Princz et al., 2007; Jordan et al., 2008, 2011; Buijs et al., 2011). They had few or no adverse effects on rabbit production performance (Verga et al., 2004; Princz et al., 2007, 2008a; 2009; Zucca et al., 2012; Bignon et al., 2012), whereas they may reduce stress, decrease aggressive interactions and fighting (Princz et al., 2008a; Wagner et al., 2008; Lang, 2009; Buijs et al., 2011).

Gnawing stick did not affect the production performance of growing rabbits, but reduce the incidence of abnormal behaviours, such as aggression or chewing of wire mesh (Jordan et al., 2006).

When rabbits were given the opportunity to choose between cages without or with gnawing stick, they spent slightly more time in the latter cage (53%), especially during the active period (56%) (Princz et al., 2008a). The preference of gnawing wood from nine different tree species was examined by placing 3 different sticks of trees in each cage (Princz et al., 2007).

Gnawing stick made of linden tree were the most preferred, followed by white willow and white horse chestnut. The rabbits consumed little material of white acacia and rejected black elder, European larch, European white birch and white mulberry.

White acacia gnawing stick did not affect ear injuries when compared to a control without gnawing stick (Princz et al., 2009). Hard wood of white acacia was less efficient in reducing the incidence of ear injuries than soft wood of linden as compared to cages without gnawing stick (Princz et al., 2007; Figure 4).

Figure 4.
Incidence of ear injuries in growing rabbits depending on the absence of gnawing stick (No) in the cage or inserted stick made of White acacia or Linden tree (Princz et al., 2007).

In addition to the type of material of gnawing stick, their size and position in the cage are also important. Large hardwood gnawing sticks hanging free moving from the top of the cage, make gnawing difficult (Luzi et al., 2003).

According to Princz et al. (2007) softwood gnawing sticks, which are horizontally attached to the side wall of the cage are easily accessible and considered more suitable for gnawing (Figure 5).

Figure 5.
The gnawing stick should be placed in the cage so that the rabbits have easy access.

Birolo et al. (2022) observed group housed rabbits with or without gnawing hay blocks as enrichment material. The presence of gnawing blocks scarcely affected performance criteria and the behavioural time budget, but it reduced fear response as assessed in the open field test and novel object test.

Supplementation of hay decreased slightly production performance and slaughter results, and significantly reduced ear injuries, especially in larger groups (Szendrö et al., 2015). Supplementation of hay or straw was economically not favourable. The material falling to the floor can bear health risks when contaminated with faeces and urine.

CONCLUSIONS

Installation of elevated platforms is useful tool to enrich cages and floor rearing systems. Raised platforms increase the floor space and improve the animals ability to move and to choose the best place in the cage or pen.

The easiest way for environment enrichment is using gnawing stick. Softwood (e.g., linden tree) gnawing stick placed at the head height of rabbits is best suited. It reduces aggression, fights and injuries, especially in group-reared rabbits.

Enrichment increases the production costs of rabbit meat. Since rabbit meat is more expensive than other meat of farm animals, such as poultry and pork, it may not be affordable by poorer consumers. The consumers should be given freedom to decide on which housing system they accept.

References

Abdel-Hamid T.M. 2018. Effect of stocking density on growth performance, some blood parameters and carcass traits in purebred Californian and crossbred rabbits. J. Adv. Vet. Anim. Res., 5, 265-274.
Aubret J. M., Duperray J. 1992. Effect of cage density on the performance and health of the growing rabbit. J. Appl. Rabbit Res., 15, 656-662.
Bessei W., Tinz J., Reiter K. 2002. Die Präferenz von Mastkaninchen für Kunststoffgitter und Tiefstreu bei unterschiedlichen Temperaturen. 12th Symp. Housing and Diseases of Rabbits, Furbearing Animals and Pet Animals, Celle, Germany, 133–140.
Bigler L., Oester H. 1996. Group housing for male rabbits. 6th World Rabbit Congress, Toulouse. France. Vol. 2, 411-415.
Bignon L., Bouchier M., Coutelet G., Galliot P., Souchet C., Fortun-Lamothe L. 2012. Individual housing of young does in different sized cages: Impact on welfare, economic costs and productive data. In: 10th World Rabbit Congress, Sharm El-Sheikh, Egypt, 1045-1049.
Birolo M., Trocino A., Zuffellato A., Pirrone F., Bordignon F., Xiccato G. 2022. Use of gnawing hay blocks: Effects on productive performance, behavior and reactivity of growing rabbits kept in parks with different sex-group compositions. Animals, 12, 1212.
Botelho N., Vieira-Pinto M., Batchelli P., Pallisera J., Dalmau A. 2020. Testing an animal welfare assessment protocol for growing-rabbits reared for meat production based on the welfare quality approach. Animals, 10, 1415
Buijs S., Keeling L.J., Tuyttens F.A.M. 2011. Behaviour and use of space in fattening rabbits as influenced by cage size and enrichment. Appl. Anim. Behav. Sci. 134, 229–238.
Buijs, B., Hermans, K., Maertens, L., Van Caelenberg, A., Tuyttens, F.A.M. 2014. Effects of semi-group housing and floor type on pododermatitis, spinal deformation and bone quality in rabbit does. Animal, 8, 1728–1734.
Chu L., Garner J.P., Mench J.A. 2004. A behavioral comparison of New Zealand White rabbits (Oryctolagus cuniculus) housed individually or in pairs in conventional laboratory cages. Appl. Anim. Behav. Sci., 85, 121-139.
Dal Bosco A., Castellini C., Bernardini M. 2000. Productive performance and carcass and meat characteristics of cage- or pen-raised rabbits. World Rabbit Sci. 8, Suppl. A, 579-583.
Dal Bosco A., Castellini C., Mugnai D. 2002. Rearing rabbits on a wire net floor or straw litter: behaviour, growth and meat quality traits. Livest. Prod. Sci., 75, 149–156.
Di Vincenti L., Rehrig A.N. 2016. The social nature of European rabbits (Oryctolagus cuniculus). J. Am. Assoc. Lab. Anim. Sci., 55, 729–736.
EFSA, 2005. The impact of the current housing and husbandry systems on the health and welfare of farmed domestic rabbits. The EFSA Journal, 267, 1-140.
El-Tarabany M.S., Ahmed-Farid O.A., El-Tarabany A.A. 2019. Impact of space allowance on performance traits, brain neurotransmitters and blood antioxidant activity of New Zealand White rabbits. Prev. Vet. Med., 163, 44-50.
Farkas T.P., Dal Bosco A., Szendrő Zs., Filiou E., Matics Zs., Odermatt M., Radnai I., Paci G., Gerencsér Zs. 2016. Production of growing rabbits in large pens with or without multilevel platforms. In: 10th World Rabbit Congress, Qingdao, China, 663-666.
Finzi A., 2005. Personal communication.
Gerencsér Zs., Szendrő K., Szendrő Zs., Odermatt M., Radnai I., Nagy I., Dal Bosco A., Matics Zs. 2014. Effect of floor type on behavior and productive performance of growing rabbits. Livest. Sci., 165, 114-119.
Hansen L.H., Berthelsen H. 2000. The effect of environmental enrichment on the behaviour of caged rabbits (Oryctolagus Cuniculus). Appl. Anim. Behav. Sci., 68, 163-178.
Held S.D.E., Turner R.J., Wootton R.J. 1995. Choice of laboratory rabbits for individual or group-housing. Appl. Anim. Behav. Sci., 46, 81-91.
Hube D., Bill J., Knop E.S., Herbrandt S., Kemper N., Fels M. 2023. Physical injuries and hair corticosterone concentration in rabbit kits from single- and group-housed does kept on a commercial farm. Animals, 13, 196.
Jehl N., Meplain E., Mirabito L., Combes S. 2003. Incidence de trois modes de logement sur les performances zootechniques et la qualité de la viande de lapin. In: 10èmes Journées de la Recherche Cunicole, Paris, France, 181-184.
Jekkel G., Milisits G., Nagy I. 2007. Effects of floor type and stocking density on the behaviour modes of growing rabbits. Agriculture, 13, 150-154.
Jekkel G., Milisits G., Nagy I., Biró-Németh E. 2008. Analysis of the behaviour of growing rabbits housed in deep litter at different stages of rearing. In: 9th World Rabbit Congress, Verona, Italy, 1189-1193.
Jensen, P., 2002. The ethology of domestic animals. CABI Publishing, Wallingford, Oxon
Jordan D., Luzi F., Verga M., Stuhec I. 2006. Environmental enrichment in growing rabbits. In: Recent advances in rabbit sciences. Eds. Maertens L., Coudert P., ILVO, Melle, Belgium, 113-119.
Jordan D., Gorjanc G., Kermauner A., Štuhec I. 2008. Wooden sticks as environmental enrichment: Effect on fattening and carcass traits of individually housed growing rabbits. World Rabbit Sci., 16, 237-243.
Jordan D., Gorjanc G., Kermauner A., Štuhec I. 2011. The behaviour of individually housed growing rabbits and the influence of gnawing sticks as environmental enrichment on daily rhythm of behavioural patterns duration. Acta argic. Sloven., 98, 51-61.
Krunt O., Zita L., Kraus A., Volek Z. 2021. A review of the effects of housing system on production and welfare in growing rabbits. Anim. Sci. Pap. Rep., 38, 321-332.
Krunt O., Zita L., Kraus A., Volek Z. 2021. How can housing system affect growth and carcass traits, meat quality and muscle fiber characteristics in biceps femoris and mineral content of tibia and femur bones in growing rabbits? Livest. Sci., 249, 104531
Kustos K., Tóbiás G., Kovács D., Eiben Cs., Szendrő Zs. 2003. Effect of stocking density, floor type and feeding method on production of growing rabbits. Proc. 15th Hungarian Conference on Rabbit Production, Kaposvár, 123-128.
Lambertini L., Vignola G., Zagnini, G. 2001. Alternative pen housing system for fattening rabbits: Effect of density and litter. World Rabbit Sci., 9, 141-147.
Lang C. 2009. Klinische und ethologische Untersuchungen zur Haltung wachsender Kaninchen. Thesis Univ. Gießen, Germany.
Lang C., Hoy S. 2011. Investigations on the use of an elevated platform in group cages by growing rabbits. World Rabbit Sci., 19, 95-101.
Gidenne T., Lebas F., Fortun-Lamothe L. 2010. Feeding behaviour of rabbits. 233-252. In: de Blas C., Wiseman J. Edts. Nutrition of the rabbit, 2nd edition, CAB International
Leblatier L., Menini F.-X., Bourdillon A., Salaün J.-M., Le Floch A., Perdriau A. 2017. Effet d’un logement collectif en parc sur les performances zootechniques du lapin en engraissement en conditions d’élevage commercial. In: 17èmes Journées de la Recherche Cunicole, Le Mans, France, 51-54.
Lombardini L., Fernández N., Moreno S., Villafuert R. 2003. Habitat-related differences in rabbit (Oryctolagus cuniculus) abundance, distribution, and activity. J. Mammal., 84, 26-36.
Luzi F., Ferrante V., Heinzl E. Verga M. 2003. Effect of environmental enrichment on productive performance and welfare aspect in fattening rabbits. Ital. J. Anim. Sci., 2 (Suppl. 1), 438-440.
Maertens L. 2013. Housing regulation of rabbits in Belgium: The step by step plan. 18. International Symposium on Housing and Diseases of Rabbits, Furproviding Animals and Pet Animals, Celle (Germany), 12-19.
Maertens L., Buijs S., 2013. Performances de femelles logées temporairement en groupe dans des parcs polyvalents et en système tout plein tout vide. In: Proc. Journées de la Recherche Cunicole en France, Le Mans, France, 35-38.
Maertens L., De Groote G., 1984. Influence of the number of fryer rabbits per cage on their performance. J. Appl. Rabbit Res. 7, 151–155.
aertens L., Van Herck A. 2000. Performance of weaned rabbits raised in pens or in classical cages: First results. World Rabbit Sci., 8, 435-440.
Maertens L., Van Oeckel M.J. 2001. Effet du logement en cage on en parc et de son enrichissement sur les performances et la couleur de la viande des lapins. In: 9émes Journ. Rech. Cunicole, Paris, France, 31-34.
Maertens L., Rommers J., Jacquet M. 2011. Le logement des lapins en parcs, une alternative pour les cages classiques dans un système “duo”? In: 14èmes Journ. Rech. Cunicole, 22-23 November 2011, Le Mans, France, 85-88.
Machado L.C., Martínez-Paredes E., Cervera C., Garcia A.V. 2023. Performance of kits that born in semi-group housing system or individual cages before and after weaning. Rev. Bras. Cunicult., DOI: 10.46342/cunicultura.v23.2023.1
Martrenchar A., Boilletot E., Cotte J.P., Morisse J.P. 2001. Wire-floor pens as an alternative to metallic cages in fattening rabbits: influence on some welfare traits. Anim. Welfare 10, 153–161.
Masthoff T., Hoy St. 2019. Investigations on the influence of floor design on dirtiness and foot pad lesions in growing rabbits. Animals, 9, 354.
Masthoff T., Lang C., Hoy 2017. Einfluss der Fußbodengestaltung auf das Auftreten von Verschmutzungen und Fußläsionen bei Mastkaninchen. Proc. 20. Intern. Symposium on Housing and Diseases of Rabbits, Furproviding Animals and Pet Animals, Celle, Germany, 53-61.
Matics Zs., Szendrő Zs., Radnai I., Biróné Németh E., Gyovai M. 2002. Free chooce of rabbits among cages with different size. Proc. 14th Hungarian Conference of Rabbit Production. Kaposvár, 43-48.
Matics Zs., Szendrő Zs., Radnai I., Biró-Németh E., Gyovai M. 2003. Examination of free choice of rabbits among different cage-floors. Agric. Conspec. Sci., 68, 265-268.
Matics Zs., Szendrő Zs., Radnai I., Biró-Németh E., Gyovai M., Orova Z. 2004. Study of a two-phase rearing method for growing rabbits. In Proc. 8th World Rabbit Congress, Puebla City, Mexico, 1141-1145.
Matics Zs., Szendrő Zs., Odermatt O., Gerencsér Zs., Nagy I., Radnai I., Dalle Zotte A. 2014. Effect of housing conditions on production, carcass and meat quality traits of growing rabbits. Meat Sci., 96, 41-46.
Matics Zs., Farkas T.P., Dal Bosco A., Szendrő Zs., Filiou E., Nagy I., Odermatt M., Paci G., Gerencsér Zs. 2018. Comparison of pens without and with multilevel platforms for growing rabbits. Ital. J. Anim. Sci., 17, 469–476.
Matics Zs., Cullere M., Dalle Zotte A., Szendrő K., Szendrő Zs., Odermatt O., Atkári T., Radnai I., Nagy I., Gerencsér Zs. 2019. Effect of cage and pen housing on the live performance, carcase, and meat quality traits of growing rabbits. Ital. J. Anim. Sci., 18, 441-449,
Morisse J. P., Maurice R. 1997. Influence of stocking density or group size on the behaviour in fattening rabbits kept in intensive conditions. Appl. Anim. Behav. Sci., 54, 351-357.
Monclús R., Rödel H.G. 2008. Different forms of vigilance in response to the presence of predators and conspecifics in a group-living mammal, the European rabbit. Ethology, 114, 287–297.
Omar M.A.E., El-Shahat M., Hassan F.A.M. 2020. Impact of stocking density on growth performance, carcass traits, and economic feasibility of growing rabbits. J. Anim. Health Prod., 9(s1), 50-55.
Orova Z., Szendrő Zs., Matics Zs., Radnai I., Biró-Németh E. 2004. Free choice of growing rabbits between deep litter and wire net floor in pens. Proc. 8th World Rabbit Congress, Puebla City, Mexico, 1263–1265.
Petersen J., Schlender-Böbbis I., Mennicken, L. 2000. Evaluation of optimal slat distance in slatted floor for rabbits using behavioural studies. Proc. 7th World Rabbit Congress., July 4-7, Valencia, Spain, Vol. B, 559-565.
Podberscek A.L., Blackshaw J.K., Beattie A.W. 1991. The behaviour of group penned and individually caged laboratory rabbits. Appl. Anim. Behav. Sci., 28, 353-363.
Postollec G., Boilletot E., Maurice R., Michel V. 2008. The effect of pen size and an enrichment structure (elevated platform) on the performances and the behaviour of fattening rabbits. Anim. Welfare., 17, 53-59.
Princz Z., Orova Z., Nagy I., Jordan D., Štuhec I., Luzi F., Verga M., Szendrő Zs. 2007. Application of gnawing sticks in rabbit housing. World Rabbit Sci., 15, 29-36.
Princz Z., Dalle Zotte A., Radnai I., Biró-Németh E., Matics Zs., Gerencsér Zs., Nagy I., Szendrő Zs. 2008a. Behaviour of growing rabbits under various housing conditions. Appl. Anim. Behav. Sci., 111, 342-356.
Princz Z., Radnai I., Biróné Németh E., Matics Zs., Gerencsér Zs., Nagy I., Szendrő Zs. 2008b. Effect of cage height on the welfare of growing rabbits. Appl. Anim. Behav. Sci., 114, 284-295.
Princz Z., Dalle Zotte A., Metzger Sz., Radnai I., Biró-Németh E., Orova Z., Szendrő Zs. 2009. Response of fattening rabbits reared under different housing conditions. 1. Live performance and health status. Livest. Sci., 121, 86–91.
Rashwan A.A., Matics Zs., Szendrő Zs., Orova Z., Biró-Németh E., Radnai I. 2007. Effect of nursing method and stocking density on the performance of early weaned rabbits. Acta Agr. Kapos., 11. 1. 29-36.
Rauterberg S.L., Bill J., Kimm S., Kemper N., Fel M. 2019. Evaluation of two different flooring designs for rabbit housing in accordance with German welfare regulations: Soiling and mortality. Agriculture, 9, 257
Rommers J., Meijerhof R. 1998. Effect of group size on performance, bone strength and skin lesions of meat rabbits housed under commercial conditions. World Rabbit Sci., 6, 299-302.
Ribikauskas V., Ribikauskienė D., Skurdenienė I. 2010. Effect of housing system (wire cage versus group-housing) and in-house air quality parameters on the behaviour of fattening rabbits. World Rabbit Sci., 18, 243-250.
Roy P., Fonteniaud J., Charrier J.-F., Lebas F. 2017. Performances de croissance et d’abattage de lapins engraissés en cages ou en parcs avec une alimentation rationnée. Effet de la distribution de foin. In: 17èmes Journées de la Recherche Cunicole, Le Mans, France, 47-50.
Sommerville S., Ruiz R., Averós X. 2017. A meta-analysis on the effects of the housing environment on the behaviour, mortality, and performance of growing rabbits. Anim. Welfare, 26, 223-238.
Szendrő Zs., Dalle Zotte A. 2011. Effect of housing conditions on production and behaviour of growing meat rabbits: A review. Livest. Sci., 137, 296-303.
Szendrő Zs., McNitt J.I., 2012. Housing of rabbit does: Group and individual systems: A review. Livest. Sci., 150, 1-10.
Szendrő K., Szendrő Zs., Matics Zs., DalleZotte A., Odermatt M., Radnai I., Gerencsér Zs. 2015. Effect of genotype, housing system and hay supplementation on performance and ear lesions of growing rabbits. Livest. Sci., 174, 105-112.
Szendrő Zs., Matics Zs., Odermatt M., Gerencsér Zs., Nagy I., Szendrő K., Dalle Zotte A. 2012. Use of different areas of pen by growing rabbits depending on the elevated platforms’ floor-type. Animal, 6, 650–655.
Szendrő Zs., Princz Z., Romvári R., Locsmándi L., Szabó A., Bázár Gy., Radnai I., Biró-Németh E., Matics Zs., Nagy I. 2009. Effect of group size and stocking density on productive, carcass and meat quality traits, and aggression of growing rabbits. World Rabbit Sci., 17, 153-162.
Trocino A., Xiccato G. 2006. Animal welfare in reared rabbits: A review with emphasis on housing systems. World Rabbit Sci., 14, 77-93
Trocino A., Xiccato G., Queaque P. I., Sartori A. 2004. Group housing of growing rabbits: effect of stocking density and cage floor on performance, welfare and meat quality. World Rabbit Sci., 13, 138-139.
Trocino A., Xiccato G., Majolini D., Fragkiadakis M. 2008. Effect of cage floor and stocking density on growth performance and welfare of group-housed rabbits. In: 9th World Rabbit Congress, Verona, Italy, 1251-1256.
Trocino A., Majolini D., Tazzoli M., Filiou E., Xiccato G. 2013. Housing of growing rabbits in individual, bicellular and collective cages: fear level and behavioural pattern. Animal, 7, 633-639.
Trocino A., Filiou E., Tazzoli M., Bertotto D., Negrato E., Xiccato G. 2014. Behaviour and welfare of growing rabbits housed in cages and pens. Livest. Sci., 167, 305–314.
Trocino A., Zomeño C., Filiou E., Birolo C., Zuffelato A., Xiccato G. 2018. Performance and behaviour of growing rabbits reared in collective pens with or without environmental enrichment. In: 43 Symposium de Cunicultura de ASESCU. Calamocha, Spain, 130-135.
Trocino A., Zomeño C., Filiou E., Birolo C., White P., Xiccato G. 2018. The use of environmental enrichments affects performance and behavior of growing rabbits housed in collective pens. Animals, 9, 537.
Trocino A., Menegon F., Zomeño C., Pasqualin D., Cunial G., Xiccato G., Pirrone F., Bertotto D., Bortoletti M., Dorigo F., Lavazza A., Di Martino G. 2022. A pilot study about on-farm assessment of health and welfare in rabbits kept in different housing systems. Front. Vet. Sci. 9:936643.
Verga M., Zingarelli I., Heinzl E., Ferrante V., Martino P.A., Luzi F. 2004. Effect of housing and environmental enrichment on performance and behaviour in fattening rabbits. In: 8th World Rabbit Congress, Puebla, Mexico, 1283-1288.
Verga M., Luzi F., Petracci M., Cavani C. 2009. Welfare aspects in rabbit rearing and transport. Ital. J. Anim. Sci., 8, Suppl. 1, 191-204.
Villafuerte R., Moreno S. 1997. Predation risk, cover type, and group size in European rabbits in Donana (SW Spain). Acta Theriol., 42: 225-230.
Wagner C., Weirich C., Hoy St. 2008. Frequency of engagement with different materials by growing rabbits. Proc. 9th World Rabbit Congress, Verona, 1263-1268.
Wheeler S.H., King D.R., Robinson M.H. 1981. Habitat and warren utilization by the European rabbit, Oryctolagus cuniculus (L.), as determined by radio-tracking. Aust. Wildl. Res., 8, 581-588.
Windschnurer I., Waiblinger S., Hanslik S., Klang A., Smajlhodzic F., Löwenstein M., Niebuhr K. 2019. Effects of ground floor type on selected health-parameters and weight of rabbits reared in group pens. Animals, 9, 216.
Xiccato G., Verga M., Trocino A., Ferrante V., Queaque P.I., Sartori A., 1999. Influence de l’effectif et de la densité par cage sur les performances productives, la qualité bouchère et le comportement chez le lapin. Proc. 8èmes Jour. Rech. Cunicole, Paris, France, pp. 59–62.
Xiccato G., Trocino A., Filiou E., Majolini D., Tazzoli M., Zuffellato A. 2013a. Bicellular cage vs . collective pen housing for rabbits: Growth performance, carcass and meat quality. Livest. Sci. 155, 407–414.
Yakubu A., Adua M.M., Adamude H. 2008. Welfare and haematological indices of weaner rabbits as affected by stocking density. Proc. 9th World Rabbit Congress, Verona, 1269-1273.
Zucca D., Marelli S.P., Redaelli V., Heinzl E., Cardile H., Ricci C., Verga M., Luzi F. 2012. Effect of environmental enrichment and group size on behaviour and live weight in growing rabbits. World Rabbit Sci., 20, 89-95.