The common brushtail possum (Trichosurus vulpecula), introduced from Australia about 150 years ago, has become a major pest threatening the native biota of New Zealand. It is also an important disease vector, acting as a wildlife reservoir of infection. Conventional methods of control have had little effect on reducing the national population, so there is a quest to find more effective and humane methods. This has led to an upsurge in research aimed at increasing our knowledge of the biology of this marsupial, with an attendant increase in requirements for access to colony-housed animals.

Possums kept for research purposes have often been housed in individual cages, and several colonies have experienced high mortality rates. After capture, possums have shown inappetence, weight loss and a predisposition to infection, suggesting that this species is susceptible to post-capture stress. For our reproductive studies, research animals are only useful if maintained under conditions that ensure behavioural and physiological processes remain normal. We have adopted an ‘animal husbandry’ approach for our possum colony, where social interaction and the ability to exhibit instinctive behaviour patterns are considered as important as adequate nutrition and housing.

In this colony, group-housed possums show no signs of post-capture stress, and mortality rate has been less than one per cent (of > 600 animals housed to date). Virtually all possums gain weight over the first month of captivity. Procedures for monitoring, handling and the collection of data from these animals, are carried out with little apparent stress to either animals or staff.

Farmed juvenile blue foxes were housed either singly, in pairs, or in quartets at a stocking density of either 0.6 m2 or 1.2 m2 per animal. The effects of group size and space allocation on physiological, behavioural and production-related parameters were assessed. The results showed that the larger space allocation, although having only minor effects on the measured parameters, allowed the foxes to maintain their individual space even in the larger group sizes. Social tension within the groups affected the behavioural and production-related parameters to a greater extent than did space allocation. The sex-related dominance order, with males having easier access to feed than females, and females having more bite scars and higher serum cortisol levels than males, appears to be the major factor affecting the general performance of mixed-sex group-housed farmed blue foxes. These results suggest that group housing of farmed juvenile blue foxes could be considered as an alternative, socially enriched way of housing these animals.

In the present study, the effects of social environment on the welfare of farmed silver fox cubs were clarified. After weaning, cubs from silver fox litters were housed (1) singly, (2) in litters until the end of September and thereafter singly, or (3) in litters throughout their growing season. Separating the cubs at the onset of the species' natural dispersal time may not be strictly beneficial for the cubs because it may limit the animals' possibilities to fulfil their needs for social behaviour. However, the lower incidence of bite wounds in both the single housed cubs and the cubs from litters that were split in autumn showed some beneficial effects of separating the cubs. The cubs that were group housed in litters for the whole time were focussed on their own social system, were more averse to human presence and showed greater responses to acute stress than the cubs that were single housed for at least part of the time. However, the serum cortisol level following adrenocorticotropic hormone administration suggested that cubs that were group housed in litters were less stressed over the long-term compared with the cubs that were single housed for at least part of the time; the low incidence of stereotypic behaviour in the cubs raised in litters also supports this hypothesis. Accordingly, and despite some unsolved questions regarding interpretation of the hypothalamic-pituitary-adrenal axis activity, the results from this present study show that social contacts were important for the welfare of silver fox cubs, and suggest that farmed silver fox cubs could possibly be raised in litters without jeopardising their welfare or deteriorating their fur quality.

Enrichment of the environments of captive primates is currently of interest as both a basic and an applied research question, particularly when social and inanimate enhancements are used simultaneously. We measured the behavioural effects of two intensities of inanimate enrichment on 12 unimale-multifemale groups and 12 all-male groups from three cohorts of three to four-year-old rhesus macaques (Macaca mulatta). Half of the groups received a simple, inexpensive enrichment programme while the other groups received a more complex and costly combination of physical andfeeding enhancements. Observations were conducted on 93 subadults of both sexes during their initial year of group housing. Intensity of enrichment did not differentially affect the amount of time subjects spent in any of the activities analysed. Subjects that received the more complex programme spent only 8.3 per cent of their time using the extra enhancements. Therefore, there was little demonstrated benefit of the more costly enrichment programme. The three cohorts differed in the amount of time that they spent inactive, behaving agonistically, playing and located near a group mate. A planned comparison of one cohort that had been single-housed without visual access to social groups, to the two cohorts that had visual access to social groups during single caging, revealed differences in play and socially-located behaviour, which may have been due to differences in extra-cage conditions two years prior to the present study. When primates are housed socially with conspecifics as ‘social enhancements ‘, the relatively simple inanimate enrichment programme we used was as effective as the more costly programme. When enrichment resources are limited, inanimate enrichment efforts should be focused on monkeys that are not socially enriched.

A series of measures of calf welfare was developed through a process of expert consultation. A welfare assessment of group-housed calves was carried out on 53 UK dairy farms during the winter of 2000/01. The assessment used animal-based measures including direct observation of the calves and examination of their health history through a review of farm records. The findings from this were compiled into a profile of calf welfare which outlined the range of results for each measure used. The results fell into the three categories of respiratory health, nutrition and general appearance. A broad range of results was found across the farms visited for the measures in each of these categories. Some farms performed well for all measures taken, and no farms performed consistently badly across all aspects of calf welfare. The majority of farms combined aspects of both good and poor welfare performance.

To study the influence of maternal stress on neonatal locomotor development, rat pups of mothers housed singly and in groups were treated orally with corticosterone from 2 to 15 days of age. Control animals received almond oil vehicle only. The rat pups were subjected to swim-tests from 8 to 20 days of age to evaluate locomotor development. Swim-test performance demonstrated a retardation of locomotor development in pups treated with corticosterone (P <0.05). Retardation was most marked in the pups from group-housed mothers and between 13 and 15 days of age. Comparing pups not treated with hormones, the pups born to group-housed mothers showed significantly (P <0.05) better performance on swim-testing. The weight gain of pups from group-housed mothers was significantly (P < 0.05) higher than that of pups from individually caged mothers. Corticosteroid treatment had no effect on weight gain.

The aim of this study was to investigate how difficult it was to halter and separate a horse (Equus caballus) from a group for riding or training purposes and to describe how human-horse interactions could affect this common procedure. A total of 20 different horse groups, with a minimum of five horses in each, were studied on 14 farms in Norway, from June to October 2007. On each farm, information about the facilities, the horse and the handler was recorded. In each group, the horse owner or keeper (handler) was asked to enter the group, approach his/her horse, halter it and lead it out through the gate, then keep the horse standing out of sight from other horses for two minutes. The entire procedure was video recorded and the behaviour of the target horse, handler and other horses was subsequently scored. Only one of the 100 horses moved away from the handler when approached. Ninety-six percent of the target horses followed their handler without showing any resistance. In 75% of the tests, the other horses did not interact with the target horse and/or handler. At the gate, 26% of the handlers did not turn the target horse around before closing the gate, thereby placing themselves in a vulnerable position, with their body in very close proximity to the horse's hind legs. In conclusion, separating a horse from its group can be considered relatively safe and unproblematic, provided good management practices and trained handlers.

While group housing (GH) is mandatory in the European Union for the greater part of pregnancy, single housing in farrowing crates (FCs) during lactation that restrict sows in most of their natural behaviour patterns is still practised on a large scale. Research is urgently needed to develop alternative farrowing systems that improve sows’ welfare. Therefore, sows in three different farrowing systems – pens with FC, loose housing (LH) pens and GH for six sows – were compared regarding the level of skin injuries and their active and resting behaviour. A skin injury score was assessed for 15 body parts of 102 sows in six batches on 3 days (days 1, 14 and 34). In total, the active and resting behaviour of 77 sows in six batches was examined on 3 days (days 18, 25 and 32) between 0700 h and 1900 h by means of a scan sampling method. The suckling behaviour and the level of cross-suckling were analysed in GH by means of direct observation in four batches during three 4-h sampling periods (days 17, 24 and 31). No significant differences were found in total skin injuries when the sows entered the systems (day 1), but GH sows showed significantly higher total skin injuries compared to FC and LH sows in the middle (day 14) and at the end (day 34) of the lactation period. A significant difference between FC and LH sows was never seen. Differences were found for the proportion of different body postures between the three systems. The odds for lying in lateral recumbency versus standing and sitting versus standing were significantly higher for FC and LH sows compared to GH sows. Additionally, sows were significantly more likely to be standing as opposed to lying in lateral recumbency as the lactation period progressed. Cross-suckling was a frequent behaviour in GH, seen in 35.0% of all successful suckling bouts. However, only an average of 0.56 piglets per successful suckling bout was observed cross-suckling, suggesting only a few piglets were engaged in cross-suckling. In conclusion, the skin injury score was only moderately increased in GH compared to FC and LH and comparable to pregnant group-housed sows, both free farrowing systems seemed to be an environmental enrichment for lactating sows and good management cannot prevent the occurrence of cross-suckling in a GH system, but can probably reduce it.

The low feed intake and stress associated with abrupt weaning in conventional pig farming often result in poor post-weaning performance, which is related to impaired intestinal function. We investigated effects of housing conditions before weaning on performance around weaning of relatively light and heavy piglets. Before weaning, piglets were housed either with five sows and their litters in a multi-suckling (MS) system or in pens with individually housed sows in farrowing crates (FC). After weaning at 4 weeks of age (day 0), 16 groups of four piglets (two light and two heavy litter-mates) were housed under equal conditions in enriched pens. Mannitol (day −5 and day 5) and galactose (day 5) were orally administered as markers for gastrointestinal carbohydrate absorption, and after 20 min a blood sample was taken (sugar absorption test). In addition, BW, feed intake and faecal consistency as an indicator for diarrhoea, were assessed frequently during 2 weeks post-weaning. Pre-weaning housing, weight class and their interaction did not affect post-weaning faecal consistency scores. Weight gain over 2 weeks did not differ between pre-weaning housing treatments, but MS piglets gained more (0.67±0.12 kg) than FC piglets (0.39±0.16 kg) between days 2 and 5 post-weaning, P=0.02), particularly in the ‘heavy’ weight class (interaction, P=0.04), whereas feed intake was similar for both treatments. This indicates a better utilisation of the ingested feed of the MS piglets compared with the FC piglets in the early post-weaning period. Pre-weaning mannitol concentrations were unaffected by pre-weaning housing, weight class and their interaction. On day 5 post-weaning, however, MS piglets had a lower plasma concentration of mannitol (320 v. 592 nmol/ml, SEM=132, P=0.04) and galactose (91 v. 157 nmol/ml, SEM=20, P=0.04) than FC piglets, regardless of weight class. In conclusion, MS and FC piglets differed in aspects of post-weaning gastrointestinal carbohydrate absorption and in weight gain between days 2 and 5 after weaning, but pre-weaning housing did not affect feed intake, weight gain and measures of faecal consistency over the first 2 weeks after weaning.

Changes in the drinking behaviour of pigs may indicate health, welfare or productivity problems. Automated monitoring and analysis of drinking behaviour could allow problems to be detected, thus improving farm productivity. A high frequency radio frequency identification (HF RFID) system was designed to register the drinking behaviour of individual pigs. HF RFID antennas were placed around four nipple drinkers and connected to a reader via a multiplexer. A total of 55 growing-finishing pigs were fitted with radio frequency identification (RFID) ear tags, one in each ear. RFID-based drinking visits were created from the RFID registrations using a bout criterion and a minimum and maximum duration criterion. The HF RFID system was successfully validated by comparing RFID-based visits with visual observations and flow meter measurements based on visit overlap. Sensitivity was at least 92%, specificity 93%, precision 90% and accuracy 93%. RFID-based drinking duration had a high correlation with observed drinking duration (R 2=0.88) and water usage (R 2=0.71). The number of registrations after applying the visit criteria had an even higher correlation with the same two variables (R 2=0.90 and 0.75, respectively). There was also a correlation between number of RFID visits and number of observed visits (R 2=0.84). The system provides good quality information about the drinking behaviour of individual pigs. As health or other problems affect the pigs’ drinking behaviour, analysis of the RFID data could allow problems to be detected and signalled to the farmer. This information can help to improve the productivity and economics of the farm as well as the health and welfare of the pigs.

Although rabbit does are generally single housed on rabbit farms worldwide, it has been suggested by some specialists and recommendation of organic rabbit production systems that group housing of does is more comfortable and similar to the living conditions of the European wild rabbits. The aim of this experiment was to compare production of single-caged (S) and group-housed does (G). The S does were housed in commercial rabbit cages (floor area 0.32 m2 and 0.3 m high). In treatment G, four does and one buck were housed in four pens measuring 7.7 m2 (half of the floor was deep litter and the other half was plastic slat), with four nest boxes in each pen (n = 16). In treatment S, approximately half of the does (n = 18) were inseminated 2 days after kindling (S-33), whereas in the remaining does (n = 16) AI was done 11 days after kindling (S-42). A single-batch system (all of the does in the group were inseminated on the same day) was used in both S treatments. Kindling rates were 77.6%, 85.2% and 45.6% in treatments S-33, S-42 and G, respectively (P < 0.05). During the experiment, the percentage of does that kindled 0, 1, 2, 3, 4 and 5 times were 17%, 25%, 17%, 25%, 17% and 0% (G); 0%, 0%, 0%, 8%, 69% and 23% (S-33); and 0%, 0%, 17%, 58% and 25% (S-42, in this treatment does had a maximum of four kindlings). There were no significant differences among treatments for litter size. In treatments S-33, S-42 and G, suckling mortality was 14.0%, 15.2% and 38.5%, respectively (P < 0.001); survival of does was 71%, 81% and 50% (P = 0.084); and faecal corticosterone concentrations were 61, 54 and 175 nmol/g (P < 0.001). The high mortality of kits was associated with stress and aggressive behaviour of does, including scratching, biting or killing the kits, which resulted in the high rates of mortality and culling, as well as shorter lifespan of does. Because of high stress, increased mortality and morbidity, and low productivity, group housing of rabbit does resulted in poorer animal welfare and increased production costs, and therefore is not recommended.

The present study was designed to analyze the growth performance, behavioral patterns and intensity of injuries of weaned pigs (26 days) during a rearing period of 6 weeks. The farrowing system (group housing (GH) v. single housing (SH)) and the post-weaning regrouping weight class (light, medium, heavy) were considered as the main factors. A number of 120 GH-pigs and 120 SH-pigs were kept in three batches (20 pens, 12 pigs each). The GH- and SH-pigs were divided by weight into three groups: light (5 to ⩽7 kg), medium (>7 to ⩽9 kg) and heavy (>9 to ⩽12 kg), with two pigs of six different litters in each pen. The pigs were weighed individually at weaning (week 1) and during rearing (weeks 2, 3 and 7). The feed conversion ratio (FCR) was calculated between weeks 1 and 7. The duration and number of fights (NF) per pen and hour were determined by continuous sampling (40 h after weaning). Lesions of the integument were scored into four classes (none, minor, medium, severe) and recorded at weaning and 48 h afterwards. The farrowing system had no effect on the weights in week 1 (GH: 7.8 kg v. SH: 7.7 kg; week as linear, quadratic regression nested within housing systems) or in week 7 (GH: 29.4 kg v. SH: 28.6 kg). The body weights were influenced significantly by the weaning weight class (light: 11.7 kg (s.e.m.: 0.30), medium: 14.8 kg (s.e.m.: 0.22), heavy: 17.3 kg (s.e.m.: 0.26)). The FCR of the GH-pigs was 1.64 (s.e.m.: 0.03) and 1.58 (s.e.m.: 0.03) for SH-pigs. A reduced agonistic behavior of the GH-pigs was observed with 2.1 fights per pen and hour (s.e.m.: 0.07) v. the SH-pigs with 4.6 fights per pen and hour (s.e.m.: 0.05). The fight duration of the GH-pigs with 10.3 s per pen and hour (s.e.m.: 1.07) was significantly lower in comparison to the SH-pigs with 18.8 s per pen and hour (s.e.m.: 1.06). The SH-pigs had more new skin lesions at the shoulders than the GH-pigs 48 h after weaning (P < 0.05). In conclusion, early mixing of unacquainted litters during lactation had no influence on their growth performance during rearing but reduced agonistic behavior and lesion score difference during the first 2 days after weaning. No significant interaction between the farrowing system and weaning weight class was detected with regard to growth performance and NF.

Upcoming nesting behaviour traits, such as the exact oviposition time or the time spent in the nest, have a direct impact on economically relevant aspects. Hens which stay for a long time inside the nest box, require more nest capacity which result in higher investments for the farmer. This is similar to flocks in which most of the layers have the need to lay their eggs in a short time frame during the day. For both of these nesting behaviour traits, published data have shown strain differences. While brown layers are more relaxed in terms of their oviposition time, almost 90% of a white layer flock lay their eggs within 3 hours during the morning. Additionally, a white layer on average occupies the nest 15 minutes longer than a brown layer. The estimated heritabilities for both traits are on a medium level of around h² = 0.25, and are therefore susceptible to genetically-linked changes. Lower heritabilities are estimated for indirect nesting behaviour traits such as the time interval between two consecutively laid eggs (h² = 0.09) or the total clutch size (h² = 0.25). Ranging behaviour traits also show heritabilities on a medium level. The published heritability for the frequency of passages as well as for the length of stay in the winter garden is h² = 0.24, however, their relationship to the most important selection trait ‘egg number’, is negative. The laying performance tested with the Funnel Nest Box (FNB) show differences to the recorded egg number of full sibs which have been tested in cages. Tabled genetic parameters showed low correlations for the egg number at peak production (rg = +0.2 to rg = +0.4) which could be explained by genotype x environment effects. Other traits like egg weight, early egg production and body weight show high correlations between both testing environments.

We studied a group housing system as an alternative to the traditional pair housing of juvenile mink. The focus was on both the welfare and production of mink. The pairs were housed in standard mink cages, whereas the groups were in row cage systems consisting of three standard mink cages connected to each other. The welfare of the mink was evaluated by behavioural observations (stereotypies and social contacts), evaluation of the incidence of scars assumed to be caused by biting, and adrenal function (serum cortisol level after adrenocorticotropic hormone (ACTH) administration and adrenal mass). Feed consumption, pelt length, quality and price were used for comparing the two housing systems from the economic point of view. Although the incidence of scars showed that there might have been more aggressive behaviour among the group-housed than among the pair-housed mink, this was not observed unambiguously in behavioural observations, and, at least, aggression did not cause mortality or serious injuries to the animals as has been observed in some earlier studies. In addition, the housing system did not affect pelt size, and, although the quality of the pelts was slightly lower in the group than in pair-housed mink, there was only a tendency for lower pelt prices. The lower pelt prices in the group-housed mink might even be partially compensated for by the group-housed mink eating 10% to 20% less in the late autumn, due to thermoregulatory benefits, than their pair-housed conspecifics. The results on the frequency of stereotypic behaviour (but not adrenal function) suggest that the group-housed animals were possibly less stressed than the pair-housed animals. Group housing of juvenile farmed mink in a row cage system cannot be recommended before the effects on welfare and production are clarified in further studies.

The aim of this experiment was to reduce piglet stress and improve performance following moving and mixing at weaning by use of the anti-aggressive drug amperozide and the practice of co-mingling piglets during lactation. Thirty-six piglets weaned at 29 days of age were allocated to a 2 × 2 factorial arrangement of treatments as follows: (1) injection of 1 ml amperozide or placebo (0.9% saline) at the time of weaning, and (2) co-mingling or no comingling of piglets from day 10 of lactation to weaning. At weaning all piglets were injected with pliytohaemagglutinin or saline, their change in skin-fold thickness was measured 24 h later and behaviour was recorded every 5 min for the first 120 min after weaning. At 4 and 24 h after weaning the depth and extent of injuries were recorded. Daily live-weight gain, apparent voluntary food intake and food conversion ratio were not improved (P > 0.05) by administration of amperozide or co-mingling of piglets during lactation. Cell-mediated immunity, as evidenced by a 0.17 proportional decrease (P <; 0.001) in skin-fold thickness following the injection of phytohaemagglutinin, was decreased in piglets not given amperozide at weaning. Injection of amperozide caused a 0.26 proportional increase (P < 0.001) in the amount of time piglets spent lying and caused piglets to display no interest in the feeder (P < 0.001) in the first 2 h after weaning. Consequently piglets not given amperozide were more active, spent more time at the feeder and participated in more aggressive encounters (P < 0.01). A significant interaction occurred between co-mingling and amperozide for mean injury score at both 4 (P < 0.01) and 24 h (P < 0.05) after weaning. When measured 4 h after weaning, co-mingling of piglets during suckling reduced mean injury score regardless of whether piglets were given amperozide or not at weaning. When piglets were not allowed to co-mingle during lactation, amperozide reduced mean injury score proportionately by around 0-44 (P < 0.01) compared with piglets administered with saline. Despite the administration of amperozide and the practice of comingling causing a reduction in stress and an improvement in welfare in this experiment, there was no beneficial effect on performance in the first 2 weeks after weaning.

Two hundred and ten piglets weaned at 30 days of age and weighing 9 kg were allocated to a 3 × 2 factorial arrangement of treatments to examine the influence of feeder type ('wet and dry' single-space feeder (SSF), 'dry' SSF, or multi-space feeder) and method of group allocation (piglets from different litters were mixed together, or piglets were weaned with their littermates) on performance after weaning. The use of a 'wet and dry' SSF did not enhance growth rate or voluntary food intake (P > 0-05) in the 28 days after weaning. Piglets feeding from 'wet and dry' SSF grew proportionately 0-06 slower in the 28 days following weaning as a result of a 0-45 proportional decrease (P = 0.013) in growth in the 1st week. Piglets mixed together from different litters at weaning grew proportionately 0.34 faster (P = 0.010) in the first 14 days after weaning than piglets weaned as littermates. This initial difference resulted in a 0-14 proportional increase in growth rate from day 1 to 28 (385 v. 339 glday, P < 0.001). Piglets from different litters mixed at weaning consumed proportionately from 0.06 to 0.16 more food (P = 0.096) than piglets weaned as entire litters. No interactions between feeder design and the method of group allocation at weaning occurred for any of the production parameters measured. Single-space feeders failed to increase the production of weaner piglets, whilst mixing non-littermate piglets into a new social group seemingly enhanced performance from weaning to 56 days of age.

Two similar style experiments were carried out in a climate-controlled pig house to determine the effects of adverse climatic conditions and relocating and mixing on the health status and productivity of pigs. In both experiments, 120 pigs were used. The climate-controlled pig house consisted of two fully separated but identical rooms (experimental and control) with five pens each (12 pigs per pen). Pigs exposed to draught and low environmental temperature had lower daily gain (experiment 1: 45 g/day; experiment 2: 25 g/day) and higher food conversion (food: gain ratio) than pigs housed under optimal climatic conditions (control). Moreover, clinical disease signs (i.e. diarrhoea, coughing, sneezing and haemorrhagic ear lesions) were more pronounced in the experimental than in the control group. In experiment 1, pigs were relocated and mixed at 10 weeks of age either within or between the experimental and control room. Data showed clear negative effects on daily gain and clinical disease signs especially among pigs that were relocated to suboptimal climatic conditions. In experiment 2, pigs were either relocated and mixed between both rooms or they remained in their own pens. Data on daily gain and clinical disease signs revealed that the health of the pigs was strongly affected by mixing. Therefore, the present work emphasizes the importance of climatic environment and social factors in intensive pig production.

A 2 X 3 factorial experiment was designed to study the consequences of feeding strategy during rearing and pregnancy over eight parities on sow growth and body condition. Two hundred and fifty-four gilts were group-fed on a restricted scale rising to either 2·25 (L) or 2·70 (H) kg/day (12·5 MJ/kg digestible energy (DE), 193 g/kg crude protein (CP) diet) from 70 to 175 days of age. A total of 156 of the L and H gilts were then given either 1·8 (l), 2·1 (m) or 2·4 (h) kg/day during subsequent pregnancies (12·9 MJ/kg DE; 177 g/kg CP diet). The same diet was offered to a standard scale during lactation. Sows were group-housed in pregnancy and given straw bedding. Losses of sows in rearing and each parity were not associated with treatment. After rearing, data have been presented only for those sows which completed eight parities. At 175 days of age, H gilts had grown faster (P < 0·001). From 175 days to service all gilts were given the same feeding regime but L gilts put on significantly more weight than H gilts, exhibiting more efficient utilization of food. There were no statistically significant differences in weights between L and H sows after the third pregnancy but L sows gained more weight than H sows in most pregnancies. The sows grew in each parity, indicating mature body size was not achieved. The pregnancy regimes had a significant (P < 0·05) effect on live weight, P2 backfat measurement, body length, neck circumference and condition score. Pregnancy treatment h produced the heavier and fatter animals but not all treatment l sows maintained adequate backfat levels for six parities. When housed in groups and given a generous supply of straw, the nutritional requirements of sows to sustain growth and body condition suitable for a long life may be less than has been previously identified for sows housed on concrete and slats without bedding.