Individually Caged Research Articles

Housing Rabbit Does in a Combi System with Removable Walls: Effect on Behaviour and Reproductive Performance

Simple SummaryThis study focuses on the welfare and reproductive performance of rabbit does housed in individual conventional cages (C) or in different colony cages: simple (does in the group for 100% of the reproductive cycle: C1) or combi (in both individual and group caging: C2). The results showed that C2 had some benefits compared to continuous grouphousing, but both colony systems achieved lower reproductive performance levels than the conventional system. Although C2 showed some improvement on the behaviour of does, the aggressiveness of group-housing the does to establish a rank order was responsible for injuries, higher disease risks, and higher kit mortality.We evaluated the effects of two types of colony cages, in which rabbit does were always in a group (C1), and where they were in combi cages furnished with removable internal walls to allow both individual and grouphousing (C2), in addition to the control group (C: conventional individual cage), on welfare, reproductive performance, and global efficiency. Forty-eight New Zealand White nulliparous rabbit does underwent artificially insemination (AI) and were divided into three groups, and reared in the different systems for about 1 year. The reproductive rhythm provides AIs at weaning (30d). In the C1 system, does were continuously grouped, while in C2, walls were inserted four days before kindling and removed 1week after it (60% of the timesheet in group). Reproductive traits and behaviour were evaluated during the entire year. The behavioural observations were performed around days 7, 36, and 44, corresponding to the inclusion of the does in the maternal cages, the insertion of walls four days before kindling, and the removal of the walls 1week after parturition in the C2 group, respectively. The percentages of does with severe skin injuries and the distribution of the injuries on different parts of body were also registered. Does reared in conventional cages showed the greatest presence of stereotype behaviours, while the C1 group showed the highest (p < 0.05) incidence of aggressiveness after regrouping (attack, dominance features, and lower allo-grooming) in comparison to the C2 group (17% and 22%, in C2 and C1 does, respectively).Individually caged does achieved the best productive performance (sexual receptivity, fertility, kindling rate, and number of kits born alive and at weaning). The C1 group showed the lowest performance (p < 0.05), whereas C2 showed an intermediate one. Does housed in the combi cage (C2) had higher (p < 0.05) receptivity and fertility rates and higher numbers of kits born alive and at weaning (79.2% and 76.2%; 7.95 and 7.20, respectively) than the C1 group, but lower values (p < 0.05) than does that were individually housed.

Productivity, reproduction and welfare status of White Leghorn hens under cage and floor housing systems

At 18th week, a total of 450 WLH layer birds from a single hatch were randomly assigned into three treatment groups viz. individual cage, colony cage and floor housing. The performance of hens with regards to sexual maturity, hen-day egg production, egg qualities and welfare parameters in three different housing conditions up to 36 wk of age were assessed. There were significant differences (P<0.05) in the welfare status regarding feather conditions, claw length, gait scores and tonic immobility of the birds between the managemental conditions. While significantly higher (P<0.05) fearful response and time for first peck (response to novel object test) was observed in individual cage layers than the floor and colony birds. The ASM was lower in individual cages (126.76±3.64d) than floor (131.11±13.40d). The hen day egg production till 20th week was higher in colony ages than the floor. During 28–32 weeks individually caged layers had significantly higher hen day egg production (P<0.05) than the colony or floor reared layers. However, during 32–36 weeks (peak summer) the colony reared layer had more egg production (P<0.01) than the colony or floor reared layers. There were significantly difference (P<0.01) in the yolk weight, yolk index, albumin index and Haugh unit between the housing system. The yolk colour was also significantly (P<0.05) darker in individual and colony cages compared to floor reared birds. The present indicates that the WLH layers showed better welfare status when reared on floor but production performance and egg quality was superior in cage type housing system.

Rabbit preference for cages and pens with or without mirrors

Five-week-old Pannon White rabbits were housed in a closed climatized rabbitry and randomly assigned to either pens (56 rabbits) having a basic area of 1 m 2 with a stocking density of 16 and 12 rabbits/m 2 or to 18 individual cages (0.24 m 2/cage). The pens and the cages were divided into two halves and animals could move freely between the two halves through swing doors. The walls of one half of the pens and cages were completely covered with mirrors while the other half was covered with white plastic panels. A 24 h video recording was made twice a week using infrared cameras and the number of rabbits in each pen and cage was counted every 15 min. The duration of the trial was 6 weeks. The lighting period was 16L/8D. In each half of the cage or pen, a feeder and nipple drinkers were available and feed intake was measured separately. Throughout the entire rearing period, 72% of the individually caged rabbits showed a preference for the cage half enriched with mirrors ( P < 0.001). This preference decreased slightly with increasing age. Preference toward the cage half provided with mirror walls was independent of the time of day; in other words, during the active period (23:00–05:00) corresponding to the dark part of the day, rabbits continued to prefer the mirrored half even if the vision of the reflected image was reduced. The presence of conspecifics at different stocking densities (12 vs. 16 rabbits/m 2) did not reduce this interest in mirrors: averaging the ages, 66% of animals living at 16 rabbits/m 2 stocking density and 63% of those living at 12 rabbits/m 2 density were found in the half pen with mirrors ( P < 0.001). Group-penned rabbits showed a marked preference toward mirrors during the active period (73–76% for 12 and 16 rabbits/m 2 stocking densities, respectively; P < 0.001). The results suggest that the presence of mirrors offers advantages perhaps related to comfort and welfare, and therefore might be used as environmental enrichment for fattening rabbits and advised for rabbits caged individually for long periods.

The Effect of Social Environment on Markers of Vascular Oxidative Stress and Inflammation in the Watanabe Heritable Hyperlipidemic Rabbit

Previous research demonstrated that social environment can influence progression of atherosclerosis in the Watanabe Heritable Hyperlipidemic (WHHL) rabbit. This study examined the effect of social environment on markers of oxidative stress and inflammation to clarify the physiological pathways potentially responsible for the influence of social environment on disease. WHHL rabbits were assigned to 1 of 3 social groups: an unstable group, in which unfamiliar rabbits were paired daily, with the pairing switched each week; a stable group, in which littermates were paired daily; and an individually-caged group. The stable group engaged in more affiliative social behavior than the unstable group. The unstable group showed more agonistic behavior compared with the stable group and higher C-reactive protein levels than the individually caged group. The individually caged group was behaviorally sedentary, had higher 24-hour urinary catecholamine levels than the other groups, and exhibited higher NAD(P)H-oxidase activity in the aortic arch relative to the stable group. The results suggest that social environment creates distinct behavioral contexts that can affect markers of inflammation and oxidative stress early in the development of atherosclerosis. Specifically, physical inactivity associated with individual caging affects indices of oxidative stress and inflammation. These pathophysiological markers may help to explain behaviorally related differences in the extent of atherosclerosis observed in prior studies.

A comparison of the effects of feeding treatments and lighting on age at first egg and subsequent laying performance and carcase composition of broiler breeder hens

1. The effects of the growth curve from 15 to 20 weeks, age at photostimulation and pattern of photostimulus on sexual maturity, egg production and egg weight were evaluated in two trials with broiler breeder females to 56 and 34 weeks of age (housed in litter pens and individually caged, respectively). Carcase composition and reproductive morphology of hens varying in laying efficiency were measured in the second trial. 2.1. Trial 1: Four growth curves were applied from 15 to 20 weeks to pullets housed in litter pens. Birds were transferred from 8- to 10-h photoperiods at 20 or 24 weeks of age, followed by weekly increments of one hour to reach a 16-h final photoperiod. 2.2. Lower-than-recommended body weights at 20 weeks significantly delayed sexual maturity, reduced peak rate of lay, total eggs and mean egg weight. However, double-yolked egg production was lower, resulting in non-significant differences in settable egg numbers between body weight treatments. 2.3. Birds reared to the heaviest body weight exhibited a significantly advanced sexual maturity, but total egg numbers, peak rate of lay and mean egg weight were not significantly affected. However, the laying of more double-yolked eggs resulted in a decrease in the number of settable eggs. Delaying photostimulation to 24 weeks significantly retarded sexual maturity, reduced total and settable egg numbers, and increased mean egg weight. A tendency for fewer double-yolked eggs was observed. 3.1. Trial 2: At 19 weeks, birds were selected from the 4 body weight categories in Trial 1 and moved to individual cages in 8 rooms. Five lighting programmes were applied. 3.2. The pattern of photostimulation applied did not affect any of the production traits measured. 3.3. At 34 weeks, 24 birds were selected for the analysis of reproductive morphology, presence of internal or multiple ovulations, and carcase composition. Eight hens showing an early age at first egg and regular egg production records, 8 birds showing erratic laying performance and 8 non-layers were killed for this purpose. There were no differences in carcase composition or reproductive morphology between these groups. No internal ovulations or double or multiple ovarian hierarchies were observed. 4. The results presented confirm that broiler breeders do not require a lighting stimulus in order to initiate ovarian activity and that, where no lighting stimulus is given, body weight or feeding level plays a critical role in stimulating the birds to attain sexual maturity. However, when a lighting stimulus is given, factors such as body weight and body composition become relatively less important in regulating the age at sexual maturity.

Density, dispersal, and feeding impact of western flower thrips (Thysanoptera: Thripidae) on flowering chrysanthemum at different spatial scales

Abstract. 1. This study evaluated the effect of dispersal on the density and feeding impact of a phytophagous insect in relation to the spatial distribution of its host plants.2. The interaction between density, dispersal, and feeding impact of western flower thrips on flowering chrysanthemum was quantified at three spatial scales, with infested and uninfested plants either isolated in 0.25 m2 individual cages, or enclosed together in 2.25 m2 communal cages or 75 m2 greenhouses.3. In individual cages, the rate of dispersal from chrysanthemum plants to blue sticky traps increased with the density of thrips for females but not males. Uninfested plants consistently had fewer thrips when they were individually caged rather than enclosed with plants infested with adults, indicating that dispersal mediates inter‐plant distribution of thrips.4. The feeding impact of thrips on inflorescences was evaluated using the absorbance of ethanol extracts at wavelengths characteristic of yellow carotenoid pigments associated with chrysanthemum inflorescences (415, 445, and 472 nm). Increasing absorbance of extracts with increasing density of thrips per inflorescence suggests that feeding by thrips results in ruptured cells leaching carotenoid pigments.5. In communal cages, the distribution of thrips was uniform for infested and uninfested plants, whereas the density and feeding impact of thrips in greenhouses were higher for infested than uninfested plants. These results suggest that short‐range dispersal by adults homogenises the density and feeding impact of thrips among host plants only on a small spatial scale.

Routes of transmission of wobbly possum disease

Aims. To determine the routes of transmission of wobbly possum disease (WPD) virus and whether or not these would favour further examination of its potential for biological control of possums. Methods. A standard inoculum, prepared as a tissue suspension from possums which had been infected with WPD, was titrated in vivo. Possums were challenged with this inoculum by the intra-gastric, intra-tracheal and intra-dermal routes. Further possums were challenged with blood by the intra-dermal and intra-peritoneal routes, with urine by the intraperitoneal route and with homogenised mites (Trichosurolaelaps crassipes) by the intra-dermal route. Transmission was investigated between possums in closely-adjacent, individual cages and between possums in a group enclosure. Results. Possums developed WPD following administration of the standard inoculum by all of the above routes, following administration of blood by the intra-peritoneal and intra-dermal routes, following administration of urine by the intraperitoneal route and following administration of homogenised mites by the intra-dermal route. Individually caged control possums did not contract WPD. All non-inoculated adult possums in the group enclosure and many joeys in direct contact with infected possums contracted WPD. Conclusion. WPD was efficiently transmitted by close contact. Without such contact transmission did not occur. Infectivity was demonstrated in tissue suspensions, blood, urine and mites. Given the routes by which possums are susceptible to these substances and the need for direct contact, infection may be spread in the wild by several mechanisms, including aggressive encounters in which blood is exchanged, contamination of wounds with urine, ingestion of contaminated food, transfer of mites during den-sharing, and other social encounters.WPD has potential as a biological control agent for possums on the basis that it is readily transmitted between individuals in close contact.

Comparison between wild-born mother-female infant interactions and laboratory-born mother-female infant interactions during the first 14 weeks after birth in individually caged cynomolgus macaques

In this study we compared mother-female infant interactions between primiparous and multiparous laboratory-born (F1) cynomolgus macaques (Macaca fascicularis) in individual cages at Tsukuba Primate Center (TPC), Japan, during the first 14 weeks of infant life. We also compared interactions between multiparousF1 mothers and their female infants with those between wild-born mothers and their female infants when mothers and their infants were housed in the same individual cages. PrimiparousF1 mothers showed significantly higher values for contact with and holding of their infants than multiparousF1 mothers. The primiparousF1 mothers also tended to behave aggressively toward their infants when the latter did not show any obviously irritating behaviors. Thus, the primiparousF1 mothers seemed to be inconsistent in terms of maternal behavior. Compared with multiparous wild-born mothers, multiparousF1 mothers moved more frequently, held their infants less frequently and acted aggressively toward their infants less frequently. However, infants ofF1 mothers, as well as infants of wild-born mothers, interacted with their mothers through approaching and playful contact with them. These findings indicate that the attitude of multiparousF1 mothers toward their infants was relatively passive. Possible reasons for the passive maternal style of multiparousF1 mothers are discussed.

Effect of Feeding Palmitic, Oleic, and Linoleic Acids to Japanese Quail Hens (Coturnix coturnix japonica).: 1. Reproductive Performance and Tissue Fatty Acids

A study was conducted to evaluate the effects of diets containing 3% of either palmitic acid (Diet PA), oleic acid (Diet OA), or linoleic acid (Diet LA) on reproductive performance, fatty acid composition of egg yolk, plasma, and liver, and total plasma phosphorus of Japanese quail. Each diet was fed to 20 individually caged hens from 5 wk of age. A 24-wk production period started at 8 wk of age. Fertile eggs for incubation were obtained by placing at random a male in the cage with the female for 15 to 20 min twice per week. The males were kept in separate individual cages and fed a turkey grower diet throughout. Feed consumption, egg production, egg output, and the number of chicks per hen were higher (P<.05) in birds fed Diet PA than in those fed Diet OA or Diet LA. Hatchability was not different (P>.05) between Diet PA and Diet OA, but they were higher (P<.05) than that of Diet LA. Quail weight at hatch from birds fed Diet LA was heavier (P<.05) than those from Diet OA, but not different (P>.05) from those fed Diet PA. Total plasma phosphorus concentration was higher (P<.05) in birds fed Diet PA than in those fed Diet LA. High levels of oleic and linoleic acids were found in egg yolk, plasma, and liver lipids from birds fed Diet OA and Diet LA, respectively. Feeding Diet PA resulted in elevated levels of palmitoleic acid in all three tissues. The highest overall reproductive performance on Diet PA suggests that palmitic acid has some physiological role in reproduction. The sustained near-maximal levels of egg production and fertility achieved in this trial indicate the superiority of the mating procedure, which would also permit testing the response of male and female birds while minimizing injuries incurred by the females.

The effects of repeated handling by familiar and unfamiliar people on rabbits in individual cages and group pens

Rabbits (New Zealand Whites, their crosses, Lop crosses, and Dutch breeds) of post-weaning ages, from two different housing systems, were observed when repeatedly approached and handled by a familiar person (worker in the animal house) or an unfamiliar person (someone unfamiliar with rabbits). Four rabbits (each in separate multi-rabbit pens) and 10 individually caged rabbits were used. No attempt was made to compare the behaviour of the rabbits in the two systems. The rabbits in both housing systems showed a reduction in fearfulness towards the handlers over the experimental period (5 days per handler). Repetition of the handling trial (three times a day) again showed definite reductions in fearfulness of the rabbits in both pens and cages. This suggests that they adapt quickly to a positive interaction with humans. The implementation of handling and approach programmes by research workers could help reduce the fear reactions in experimental animals and strengthen the human-animal bond.

Restricted feeding and reproductive performance of individually caged broiler breeder males.

Two experiments were conducted, one in the summer and another in the fall, involving 95 Hubbard broiler breeder males per experiment. Breeder males were randomly placed in individual cages at 26 (Trial 2) or 30 (Trial 1) weeks of age and provided with five levels of feed intake. The Hubbard White Mountain male Management Guide recommendation (154 g/bird/day) was designated as the control level (100%). Other levels were 115, 85, 70, and 55% of the control level. The effects of feed intake on body weight, semen volume, percent semen-packed cell volume, luteinizing hormone (LH), and testes weight were determined. Body weights were significantly decreased as feed intake was decreased. Dietary restriction levels of 115, 100, 85, and 70% had no significant effects on semen volume or semen-packed cell volume. Dietary restriction of 55% resulted in reduced semen volume, semen-packed cell volume (except in Trial 1), and testes weight. Dietary restriction had no significant effect on LH. A calculated metabolizable energy (ME) value of 346 kcal of ME/bird/day, which lies between the 85 and 70%-fed groups, should be adequate for normal body weight maintenance with the Hubbard broiler breeder male grown in individual cages.

Social dominance, reproduction, and release of the maturation-delaying chemosignal in the urine of female house mice (Mus musculus).

Five experiments were performed to investigate the effects of social status in groups of female mice on reproduction and on the release or urinary chemosignals that accelerate or delay the onset of sexual maturation in young females. Treatment of young female mice with urine from bottom-ranking mice in groups of 5 adult females resulted in delays in puberty comparable to those produced by treatment with urine pooled from females housed at moderate to high densities. Treatment of young females with urine from top-ranking females from the same groups resulted in ages for puberty not different from those of control females treated with water. There was an interaction between the social rank of a female and the stages of the estrous cycle with respect to the presence in the urine of chemosignals from grouping that delay puberty and estrus that accelerate puberty. Within groups of 5 adult mice, top-ranking females were in estrus more frequently than bottom-ranking females. Individually caged adult females treated with urine from top-ranking females were in estrus more frequently than females treated with urine from bottom-ranking females. When grouped females were separated into individual cages and mated, there was differential reproductive success: More top-ranking females conceived and bore litters than bottom-ranking females. Bottom-ranking females produced more female pups, relative to top- and middle-ranking females.

Ontogeny of aggressive-sexual behavior between males in lines of Japanese quail (Coturnix coturnix japonica) selected for male mating frequency.

Japanese quail from lines bidirectionally selected for high and low male mating frequency and from the random-bred base population were observed in an ontogenetic study of aggressive-sexual behavior. Quail were reared in sex-intermingled flocks until 28 days of age at which time half of the males from each line were housed as all-male flocks and half were transferred to individual cages. At 41 days of age, individually caged males exhibited mounting behavior to win encounters with other males. By 45 days, males from the high and control lines exhibited significantly more aggressive-sexual behavior than those from the low lines. Line x Rearing Experience interactions for mounting behavior at 45 and 56 days of age were due to the individually caged high- and control-line males' winning encounters by mounts; those maintained in flocks rarely mounted. Although some low-line males won encounters by mounts, occurrence of this behavior was infrequent. Males maintained in flocks were placed in individual cages at 57 days of age. When these males were compared with those housed in individual cages from 28 days of age, at 84 days of age and older, the Line x Rearing Experience interaction observed previously disappeared, and only differences among genetic lines were evident. Genetic and rearing experience effects are discussed as influencing agonistic and sexual behaviors.

Social dominance, reproduction, and release of the maturation-delaying chemosignal in the urine of female house mice (Mus musculus).

Five experiments were performed to investigate the effects of social status in groups of female mice on reproduction and on the release or urinary chemosignals that accelerate or delay the onset of sexual maturation in young females. Treatment of young female mice with urine from bottom-ranking mice in groups of 5 adult females resulted in delays in puberty comparable to those produced by treatment with urine pooled from females housed at moderate to high densities. Treatment of young females with urine from top-ranking females from the same groups resulted in ages for puberty not different from those of control females treated with water. There was an interaction between the social rank of a female and the stages of the estrous cycle with respect to the presence in the urine of chemosignals from grouping that delay puberty and estrus that accelerate puberty. Within groups of 5 adult mice, top-ranking females were in estrus more frequently than bottom-ranking females. Individually caged adult females treated with urine from top-ranking females were in estrus more frequently than females treated with urine from bottom-ranking females. When grouped females were separated into individual cages and mated, there was differential reproductive success: More top-ranking females conceived and bore litters than bottom-ranking females. Bottom-ranking females produced more female pups, relative to top- and middle-ranking females.

A Mixed Lactobacillus Culture in the Diet of Broad Breasted Large White Turkey Hens

Two experiments, each of 112 days duration, were conducted with Broad Breasted Large White Turkey hens held in individual cages and floor pens. Dietary treatments were either a control diet or the control diet containing 625 mg/kg of a commercially prepared mixed Lactobacillus culture. Five replicate groups (five hens/group) of individually caged hens received each treatment in Experiment 1, while five floor pens (five hens/pen) and five groups of individually caged hens (five hens/group) were assigned to each diet of Experiment 2. Egg production, daily feed intake, body weight change, fertility, hatch of fertile eggs, and hatchability of all eggs set were measured in both experiments. Egg specific gravity data were collected in Experiment 2. The presence of Lactobacillus in the diet exhibited no beneficial response through any criterion measured.

Ethanol consumption of rats in individual, group, and colonial housing conditions

Rats were housed in individual cages, in a group cage, or in a naturalistic colonial habitat, and given access to food, water, 10% ethanol, and 10% ethanol in a sweetened saline solution. Rats housed in the colony ingested significantly less total ethanol than either group or individually caged rats. When the flavored ethanol solution was removed, total ethanol intakes of all groups decreased and did not differ significantly. The data indicate that the stimuli of the colonial situation act to decrease ethanol intake when a palatable ethanol solution is available.

A note on a comparison of two systems for rearing pigs weaned at 2 days of age, involving either a liquid or a pelleted diet

SUMMARYIn two experiments pigs were weaned at 2 days of age on to a liquid milk substitute, and from 7 days were either kept to 28 days in individual cages and given the liquid diet to a scale based on live weight, or kept in groups and allowed continuous access to the same diet in the form of pellets. The dry-matter intake from the pelleted diet was considerably less than that from the liquid diet, and the live weight of the pigs given the liquid diet was considerably greater at 28 days. The type of diet did not affect the feed: gain ratio. A liquid diet seems essential to realize the maximum growth potential of pigs weaned at 2 days of age. All pigs received a pelleted diet from 29 days and their overall performance from 2 to 56 days was similar regardless of initial treatment.In a further experiment, the performance of pigs given the liquid diet was better when individually caged rather than when kept in groups.

Some Factors Influencing Feed Wastage

Two strains of commercial-type layers and two different diets were used in this study. During two observation periods, from 8 to 12 weeks in community cages and from 18–21 weeks in individual cages, weekly feed wastage was recorded.The amount of wasted feed during the first period was more dependent on the strain of bird than on the diet, similarly the regression coefficients of feed wastage on the distance of feeding space to waterers were affected more by strains than by diets. Feed wastage, of individually caged birds, was less affected by strains than that for the community cages. The overall level of feed wastage by younger birds in community cages was higher (3.6%) than that for the older, individually caged pullets (1.6%).

Adaptation of the adrenal medulla: sustained increase in choline acetyltransferase by psychosocial stimulation.

Sustained increases were produced in adrenal choline acetyltransferase of individually caged mice by placing them into groups for 10 or 15 minutes daily for 7 to 10 days. They were left undisturbed in their individual cages for the remainder of each day. As in previous experiments of similar design, adrenal catecholamines and adrenal weight were also increased, although body weight was not affected.