Effects of group housing system, pen floor type, and lactation management on performance and behaviour in rabbit does

Cage enrichment to minimize aggression in part-time group-housed female breeding rabbits

In most rabbit farms, breeding does kindle and nurse their kits in single-litter cages throughout their entire reproduction cycle. However, the protective behavior can lead to aggressive displays and injuries when the does are housed in groups. This study aimed to evaluate cage enrichment for reducing the agonistic behavior in part-time group-housed does. A total of eighty does with their 22-day-old kits were allocated to 20 multi-litter cages, with each cage housing four does and their litters for 10 days. Each multi-litter group was subjected to one of four treatments: alfalfa blocks as distraction material (A), wooden panels underneath the platforms (P), both alfalfa and wooden panels (AP), or no extra enrichment (controls, C). This experiment was replicated for three consecutive reproduction cycles. The skin injuries of the does and the kits were scored with a tagged visual analog scale before grouping and at one, three, six, eight, and 10 days after grouping. Computer vision techniques were used to continuously monitor rabbit activity and agonistic behavior (aggression and fleeing/chasing) during the first 24 h after grouping, specifically during light hours. During the first day in the group, 67.2% of the does and 13.4% of the kits acquired new injuries. This increased to 82.0 and 33.2%, respectively after 10 days in the group relative to the onset of grouping. The injury scores of the does increased toward the sixth day after grouping compared to the first (p < 0.001) and were highest on the tenth day for the kits (p < 0.001). On all the observation days, the number of injured does was higher in C compared to A (p = 0.04) and AP treatment (p = 0.005). There were no other treatment effects observed on the doe or kit skin injuries. Rabbit activity was highest after grouping but decreased after the first and second days (p < 0.001). The agonistic interactions between the does involved more fleeing/chasing behavior (62.0%) rather than aggression (38.0%). Although hierarchy fights are likely when unacquainted does are group-housed, the many animals that sustained injuries and the high injury scores confirm that part-time group housing for does is challenging and possibly inevitable. This study has shown that alfalfa, with or without wooden panels, can slightly reduce the number of injured does.

Effects of Genotype and Housing System on Rabbit Does' Aggressive Behaviors and Injuries in Smallholding Conditions

The objective of the study was to investigate the effects of housing (deep litter + concrete floor vs. deep litter + ground soil with the possibility to dig burrows), and genotype (Mecklenburg or Hyplus) on aggressive behaviour, social contacts, does' and kits' injuries, and progeny mortality. Twelve groups of six rabbit does (n = 72) were assigned to four treatments (two housing systems and two genotypes). Aggressive behaviour of does, number of injuries on does and kits, and postnatal kit mortality were recorded. The effects of housing and genotype were tested using multivariate GLMM Models. We found that the housing treatment in interaction with the genotype had a significant effect on aggressive behaviours in group housed does (F_3,12 = 14.34, p = 0.0003), where the lowest incidence of aggression was in Mecklenburg does housed on ground soil. Reduced aggression was reflected in a lower number of injuries in does (F_3,68 = 10.51, p < 0.0001), number of injuries in kits, and kit mortality (F_3,1 = 4.59, p < 0.0001, F_3,54 = 43.94, p < 0.0001). The results indicate that the proper combination of genotype and housing should be carefully considered for breeding to reduce aggression and injury in group housed does.

Effect of group size and escape enrichment on reproductive performance of breeding does in part-time group housing

Societal demands for group housing of social farm animals such as rabbits are increasing due to animal welfare concerns. When breeding does are housed in groups, maternal protective behaviour negatively affects the reproductive performance of the does. In part-time group housing, does are housed in single-litter cages starting shortly before parturition until the first part of lactation and then group housed for the second part after their protective behaviour has diminished and the kits are more resilient. The aim of this study was to evaluate the reproductive performance of breeding does in a part-time group housing system with provision of escape enrichment and different group size (and concomitant different stocking density, as pen size remained unchanged). For each of the four consecutive reproductive cycles, 42 does with their kits switched at 22 d post-partum (pp) from single-litter to group housing for a total period of 13 d in pens of 200×102 cm by removing walls between four adjacent single-litter cages. Newly created group pens (N =12 pens per treatment) varied in group size, stocking density and enrichment: groups of either three or four does were divided over same-size pens with or without escape enrichment (2×2 factorial design). The escape enrichment was comprised of two sets of PVC pipes and two extra elevated platforms. Does were weighed and kits counted at parturition, after which kits were cross-fostered. Kits were counted and weighed again 22 and 35 d pp. Results for mean doe fertility (90.0%), number of kits (9.1 kits/litter) and kit weight (1037.3 g/kit) at weaning were comparable with professional farms using single-litter cages. No significant effects of group size and escape enrichment were found for any of the reproductive parameters. While housed in group, seven does were removed from the experiment, from which four does were severely injured. Post-grouping kit mortality was rather low (6.7%), but three kits were euthanised due to severe injuries. In conclusion, provision of escape enrichment and altered group size (and stocking density) had no profound effect on the reproductive performance of part-time group housed does.

A pilot study about on-farm assessment of health and welfare in rabbits kept in different housing systems

This pilot study tested an on-farm protocol based on resource, management, and animal-based measures to evaluate the on-farm health and welfare of rabbits kept in four different housing systems. In detail, the four housing systems were (1) standard breeding cages for reproducing does (3,300 cm²) with their litters associated with bicellular cages for growing rabbits (1,200 cm²); (2) dual-purpose cages for both reproducing does and growing rabbits (3,655 cm²); (3) enriched cages (4,739 cm²) for both reproducing does and growing rabbits equipped with a wire-mesh elevated platform (1,015 cm²); (4) parks (30,977 cm²) made up of four modules (7,744 cm² each) joined by removing the wire net walls between them with growing rabbits kept in collective parks and reproducing does individually in the single modules. A total of 12 commercial farms (three farms/four housing systems) were visited during three seasons (summer, autumn, and winter) on two occasions each: (1) a pre-weaning visit for recordings on reproducing does and litters and (2) a pre-slaughtering visit for recordings on growing rabbits. At the pre-weaning visit, the prevalence of health concerns did not differ among does and litters kept in the different housing systems. At the pre-slaughtering visit, a higher prevalence of dermatomycosis was found in farms with dual-purpose cages and parks. Overall, taking into account the limitations due to the small sample size per housing system and the field conditions, the on-farm assessment tested in the present pilot study did not highlight major differences in the welfare and health of reproducing does and their kits as well as of growing rabbits in farms using different housing systems, which need to be confirmed on a large number of farms. The study also outlined the role of several management and environmental factors changing from one farm to another, which stresses the troubles of accounting for on-farm rabbit welfare and health exclusively to the housing system.

Levels of testosterone, progesterone and oestradiol in pregnant-lactating does in relation to aggression during group housing

The neuroendocrine regulation of rabbit maternal behaviour has been explored in detail. However, little is yet known about the hormonal regulation of aggression in concurrently pregnant-lactating does, a reproductive condition that prevails during group housing of rabbits on farms. Therefore, in this study we determined the relation between a) the levels of progesterone, testosterone, and oestradiol during lactation; b) the anogenital distance at artificial insemination; and c) the timing of grouping with the intensity of agonistic behaviour, published previously. We performed four consecutive trials, where three groups of eight does each were artificially inseminated on day 10 postpartum (pp) and grouped on either day 12, 18 or 22 pp. Using Dipetalogaster maxima, a reduviid blood-sucking bug, we collected blood samples during the pregnant-lactating phase (days 13, 15, 17, 19, 21, 23 pp) on one or two randomly chosen does per treatment group. Testosterone levels varied little across the pregnant-lactating phase, agreeing with results from pregnant-only rabbits, while progesterone levels increased from day 3 (=13 dpp) to day 7 (=17 dpp) and remained unchanged until day 13 (=23 dpp) of pregnancy. All oestradiol concentrations fell below the limit of detection. Overall, all concentrations were slightly lower in comparison to rabbit studies with pregnantonly does. The agonistic behaviour was not related to the respective hormonal concentrations at grouping. In conclusion, the time point of grouping does after artificial insemination (AI) in the semi-group housing system only had a weak influence on aggression and the hormonal profile did not indicate an optimum time for grouping.

Part-time grouping of rabbit does in enriched housing: effects on performances, injury occurrence and enrichment use

Collective housing is perceived as a possible way to improve rabbit welfare, especially among adult females, which are normally individually housed. Part-time group housing seems to allow a better balance between welfare and health than continuous group housing, but practical implementation and consequences for reproductive performance have not been extensively studied. The aim of this work was to compare weight, feed intake, litter size, injury occurrence, body integrity, and spatial location of female rabbits housed part-time in group housing (PGH group, n = 32) or housed individually (IH group, n = 8). Females were grouped by opening connecting hatches between four individual enriched cages (platform, wood stick and gnawing block). Collective housing started 12 days after artificial insemination and was interrupted at the 10th day (instead of the 15th day later as originally planned) due to high injury rates and severe injuries caused by fighting. The proportion of injured females increased from 25% on the first day of grouping to 63% on the 10th day. Female weight gain during the experiment was similar in the two groups. Litter size at weaning was 9% lower in the PGH group than in the IH group (9.2 vs 10.0, P < 0.01). Platform use was recorded in 32% of the observations and was the highest during the 2 weeks before weaning (46% and 47% of total observations, P < 0.05). During the grouping period, there were at least two females in the same housing unit in 59.4% of the cases, at least two females were located on the same level in 31.3% of the cases. In conclusion, connecting individual cages is an ergonomic solution for part-time group housing, but does not prevent fights for the establishment of a social hierarchy. This is detrimental to the health and body integrity of female rabbits.

The Economics of Rabbit Farming: A Pilot Study on the Impact of Different Housing Systems

This research evaluates the economic sustainability of rabbit farms using different housing systems-bicellular (BI), conventional dual-purpose (DP) and enriched cages designed according to the World Rabbit Science Association guidelines (WRSA)-through a field-based study involving six farms over the course of five years. The cages were compared based on three productivity indices expressed in kg of produced live weight/m² and on eight cost indices expressed in EUR/kg of produced live weight. The results showed that WRSA significantly reduced the productivity index per walkable cage area in buildings and cages, thanks to the longer platform area included in the cage compared to the other systems. Concerning cost indexes, total variable costs were not different among housing systems, whereas significant differences were observed within costs items. As for the feed costs, DP underperforms compared to BI or WRSA (1.15 vs. 1.02 and 0.99 EUR/kg produced live weight); for drugs costs, BI was less competitive compared to DP and WRSA (0.12 vs. 0.06 and 0.05 EUR /kg). In conclusion, under the conditions of the present study, the economic results of farms that adopted housing systems designed to improve rabbit welfare, such as WRSA enriched systems, were economically sustainable and, comparable to conventional housing systems based on BI or DP cages, also provided a significant reduction in drug use in the tested farms. A comprehensive collection of data from more farms at a European level would be necessary to confirm these results on the economics of farms adopting alternative housing systems for rabbits.

Effect of different housing systems (single and group penning) on the health and welfare of commercial female rabbits

In recent decades, concern about rabbit welfare and sustainability has increased. The housing system is a very important factor for animal welfare. However, information about how different available housing types for female rabbits affect their health status is scarce, but this is an important factor for their welfare. Hence, the objective of this study was to evaluate the health status of female rabbits in five common housing systems: three different single-housing systems with distinct available surfaces and heights; a single-housing system with a platform; a collective system. Female rabbits in the collective and platform cages had greater cortisol concentrations in hair than those in the single-housing system with no platform. Haptoglobin concentrations and kit mortality rates during lactation were greater for the collective-cage female rabbits. The collective group had more culled females and more lesions than in the other groups. The main reasons for culling in all the groups were reproduction problems and presence of abscesses, and the collective group of females was the most affected. In conclusion, it appears that keeping females together in collective systems negatively affects their health status and welfare, while single-housing systems imply lower kit mortality rates during lactation and cortisol concentrations, and fewer lesions in female rabbits.

Health and welfare of rabbits farmed in different production systems

The AGRI committee of the European Parliament requested EFSA to assess the welfare of rabbits farmed in different production systems, including organic production, and to update its 2005 scientific opinion about the health and welfare of rabbits kept for meat production. Considering reproducing does, kits and growing rabbits, this scientific opinion focusses on six different housing systems, namely conventional cages, structurally enriched cages, elevated pens, floor pens, outdoor/partially outdoor systems and organic systems. To compare the level of welfare in the different housing systems and rabbit categories, welfare impact scores for 20 welfare consequences identified from the literature were calculated, taking their occurrence, duration and severity into account. Based on the overall welfare impact score (sum of scores for the single welfare consequences), obtained via a 2‐step expert knowledge elicitation process, the welfare of reproducing does is likely (certainty 66–90%) to be lower in conventional cages compared to the five other housing systems. In addition, it is likely to extremely likely (certainty 66–99%) that the welfare of kits is lower in outdoor systems compared to the other systems and that the welfare is higher in elevated pens than in the other systems. Finally, it is likely to extremely likely (certainty 66–99%) that the welfare of growing rabbits is lower in conventional cages compared to the other systems and that the welfare is higher in elevated pens than in the other systems. Ranking of the welfare consequences allowed an analysis of the main welfare consequences within each system and rabbit category. It was concluded that for reproducing does, as well as growing rabbits, welfare consequences related to behavioural restrictions were more prominent in conventional cages, elevated pens and enriched cages, whereas those related to health problems were more important in floor pens, outdoor and organic systems. Housing in organic rabbit farming is diverse, which can result in different welfare consequences, but the overall welfare impact scores suggest that welfare in organic systems is generally good.

Performance of rabbit does housed in collective pens and individual cages

<p>In society today, there is increasing concern for the welfare of farm animals. New models of rabbit breeding are proposed, such as group housing of rabbit does in a semi-group system or environmental enrichment of individual housing. This work aimed to evaluate the reproductive performance and metabolic aspects of rabbit does housed in collective pens, comparing them to individual cages provided with a platform. Forty-eight animals were distributed in 24 individual cages (40×98×57 cm; width, length and height) and four collective pens (six does per pen; 240×100×65 cm) and remained during four cycles. The does previously housed in collective pens gained less weight and reached lighter weights by the first insemination day (3669 <em>vs.</em> 3872 g; <em>P</em>&lt;0.01), but regained weight over the cycles and had a similar weight during the experiment (4306 <em>vs.</em> 4329 g). It was observed that there was a lower feed intake in the period before delivery in collective pens, which contributed to the lower kit birth weights (57.2 <em>vs.</em> 60.1 g/kit for collective pens and individual cage respectively, <em>P</em>&lt;0.05). There were no differences in perirenal fat thickness, litter size at birth and milk yield, although does housed in collective pens had a lower feed intake (499 <em>vs.</em> 526 g dry matter/d for collective pens and individual cage, respectively; <em>P</em>&lt;0.001) and lost more perirenal fat after grouping (–0.05 <em>vs.</em> +0.15 mm for collective pens and individual cage, respectively; <em>P</em>&lt;0.05), and produced less milk the day after grouping (221 <em>vs.</em> 283 g for collective pens and individual cage, respectively; <em>P</em>&lt;0.05). In collective pens, a higher number of inseminations to reach a pregnancy (1.43 <em>vs.</em> 1.24 for collective pens and individual cage, respectively; <em>P</em>&lt;0.05) and lower number of weaned (56 vs. 66 for collective pens and individual cage, respectively; <em>P</em>&lt;0.05) kits per doe per year were revealed for does in individual cages. Overall, the use of collective pens prejudiced some parameters and needs to be economically evaluated for adoption on commercial rabbit farms.</p>

A review of recent research outcomes on the housing of farmed domestic rabbits: reproducing does

<p>The housing of farmed animals is increasingly scrutinised by society and thereby subject to a change towards more animal-friendly systems. For rabbits, also kept as pets, there are no EC regulations regarding their housing under farming conditions. In many countries, studies have been carried out to improve their welfare and health under current and alternative housing systems. This paper reviews and integrates the research efforts made since the EFSA report in 2005 on reproducing rabbit does and provides some conclusions, where possible, with special emphasis on animal welfare according to the principles stated by the Welfare Quality® project, i.e. good housing, good health and appropriate behaviour. The use of an elevated platform provides greater opportunities for does and their kits to move, jumping up and down. Management and housing systems (especially flooring) must guarantee good hygienic conditions (all-in, all-out) and separation of the rabbits from their excreta for proper resting places, hygiene and health. Plastic floors and footrests and environmental enrichments (e.g. gnawing material) are also recommended. Continuous group housing systems for reproducing females have been definitively proven to challenge animal welfare by increased aggression and injuries among does and to kits. Part-time group housing systems have proven to have potential, but cannot yet be recommended in farms until major problems of aggression and injuries among animals are solved.</p>