Preferences of group-housed female mice regarding structure of softwood bedding

Bedding influences various parameters in the housing of laboratory mice, such as health, physiology and behaviour (often considered as being integral parts of welfare). Notwithstanding existent studies about bedding preferences of individually tested mice, data about group-housed mice are still lacking. The aim of this study was to find out the structure preference for softwood bedding of group-housed mice. One hundred and eight 8-week-old female mice (C57BL6/JOlaHsd and BALB/cOlaHsd) were housed in groups of three and were given one-week free access to two different bedding structures at a time. In three test combinations, softwood shaving bedding was tested versus softwood chip bedding products of three different particle sizes (fine/medium/coarse-grained). The preference test was performed in a DoubleCage system composed of two Makrolon type IIL cages, connected by a perspex tunnel. This validated system was able to detect the crossings of each individual animal with correct crossing time and direction. On the basis of these data, dwelling times on the particular bedding structures were statistically analysed as a parameter for bedding preferences. In all three test combinations, a highly significant shaving preference was detected. On average, mice spent 70% of their dwelling time on the shavings. This preference was more explicit during the light period and in C57BL/6J mice. The relative ranking of the bedding structures was: shavings > coarse-grained chips > medium chips = fine chips. By means of these results, a shaving structure as bedding can be recommended for laboratory mice, whereas fine chip structures should be avoided.     

Automatic recording of individual oestrus vocalisation in group-housed dairy cattle: development of a cattle call monitor

Oestrus detection remains a problem in the dairy cattle industry. Therefore, automatic detection systems have been developed to detect specific behavioural changes at oestrus. Vocal behaviour has not been considered in such automatic oestrus detection systems in cattle, though the vocalisation rate is known to increase during oestrus. The main challenge in using vocalisation to detect oestrus is correctly identifying the calling individual when animals are moving freely in large groups, as oestrus needs to be detected at an individual level. Therefore, we aimed to automate vocalisation recording and caller identification in group-housed dairy cows. This paper first presents the details of such a system and then presents the results of a pilot study validating its functionality, in which the automatic detection of calls from individual heifers was compared to video-based assessment of these calls by a trained human observer, a technique that has, until now, been considered the ‘gold standard’. We developed a collar-based cattle call monitor (CCM) with structure-borne and airborne sound microphones and a recording unit and developed a postprocessing algorithm to identify the caller by matching the information from both microphones. Five group-housed heifers, each in the perioestrus or oestrus period, were equipped with a CCM prototype for 5 days. The recorded audio data were subsequently analysed and compared with audiovisual recordings. Overall, 1404 vocalisations from the focus heifers and 721 vocalisations from group mates were obtained. Vocalisations during collar changes or malfunctions of the CCM were omitted from the evaluation. The results showed that the CCM had a sensitivity of 87% and a specificity of 94%. The negative and positive predictive values were 80% and 96%, respectively. These results show that the detection of individual vocalisations and the correct identification of callers are possible, even in freely moving group-housed cattle. The results are promising for the future use of vocalisation in automatic oestrus detection systems.     

Long-term automatic video recording as a tool for analysing the time patterns of utilisation of predefined locations by wild animals

The design and application of automatic video recording systems for wild animals are described. Such systems enable continuous, long-time and repercussion-free surveillance of selected areas in the field. The performance characteristics of a conventional VHS video-tape system are compared to a digital video recording system. The recordings were used to develop daily and annual plots of occurrence for the different species and to display the preferences for darkness, twilight and light phase by the different species over the year. Absolute utilisation frequency as well as relative species composition can be obtained and compared between seasons or different places. The videos also were analysed for time budgets of basic behaviour patterns like feeding, walking, observing, social interaction, flight and comfort behaviour. Automatic video technique is a highly convenient tool for systematic long-term field research on occurrence of wild animal species, daily and annual activity rhythms, behaviour and area utilisation. Such systems can be applied especially to record animals at clearings, feeding or bait places, water sources, salt licks or traps. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

长爪沙鼠与黑线仓鼠的温度选择比较

本文使用自制的陆生动物温度选择仪,对长爪沙鼠和黑线仓鼠的温度选择进行了比较,结果表明,长爪沙鼠的选择温度(29.06±0.62℃)较黑线仓鼠(26.65±0.64℃)高。这种差异可能与两种鼠的栖息环境及昼夜节律的不同有关。     

Do Male Mice Prefer or Avoid Each Other's Company? Influence of Hierarchy, Kinship, and Familiarity

In the laboratory, individual housing of male mice who otherwise show aggression is common practice. Because mice are a social species, the question arises whether this procedure is right from the animals' point of view. This study tested the preference of subordinate animals for their dominant cagemate, and vice versa, and the preference of subordinate animals for an unknown subordinate partner. Experiments that allowed male mice with different histories to choose either an inhabited or an empty cage have shown that the mice preferred the proximity of another male over individual housing. No differences in this respect were found between dominant and subordinate males, or between littermates and nonlittermates. The preference was most obvious when mice who were previously housed together were tested. The study concludes that separation and single housing for mice are not attractive solutions for overcoming aggression in group-housed male mice and that alternative approaches, such as improving the housing conditions, should be explored as a way of tempering intermale aggression.     

Involvement of diazepam binding inhibitor and its fragment octadecaneuropeptide in social isolation stress-induced decrease in pentobarbital sleep in mice.

Diazepam binding inhibitor (DBI) and its fragment, octadecaneuropeptide (ODN), are putative endogenous ligands for benzodiazepine (BZD) receptors and have been shown to act as an inverse BZD receptor agonist in the brain. A previous study suggested that the social isolation stress-induced decrease in pentobarbital sleep in mice was partly due to endogenous substances with an inverse BZD receptor agonist-like property. In this study, we examined the effects of DBI and ODN on pentobarbital sleep in group-housed and socially isolated mice to test the possible involvement of DBI and ODN in a social isolation-induced decrease in pentobarbital sleep. The socially isolated mice showed significantly shorter durations of pentobarbital (50 mg/kg, intraperitoneally, i. p.) sleep compared to the group-housed animals. When injected intracerebroventricularly (i.c.v.), DBI and ODN (3 and 10 nmol) dose-dependently shortened the pentobarbital-induced sleeping time in group-housed mice at the same dose range, but these peptides had no effect on the sleeping time in socially isolated animals. In contrast, flumazenil (16.5-33 nmol, i.c.v.), a BZD receptor antagonist, reversed the pentobarbital sleeping time in socially isolated mice to the level of group-housed animals without affecting the sleeping time in group-housed animals. The effects of DBI and ODN in group-housed mice were significantly blocked by flumazenil (33 nmol, i.c.v.). Moreover, the effect of flumazenil in socially isolated mice was significantly attenuated by DBI and ODN (10 nmol, i.c.v.). These results suggest that the changes in the activity of DBI and/or ODN are partly involved in the social isolation-induced decrease in the hypnotic action of pentobarbital in mice.     

Food discrimination and induction of preference for artificial diets in the tobacco hornworm, Manduca sexta

ABSTRACT. Feeding discrimination of Manduca larvae reared on leaves and a variety of artificial media was tested against leaves, various media, solvent fractions of leaves and media, and media components, including pure chemicals. Field-collected animals showed the same preferences as did animals cultured in the laboratory for many generations. Rearing larvae on a leaf species, an artificial diet, or homogenized leaves added to artificial diet induced a preference for that food in subsequent choice tests. Extracts of these foods using organic solvents (particularly hexane) elicited feeding choices resembling those evoked by the foods themselves: water extracts were effective as stimulants or deterrents, but responses to them differed considerably from responses to the foods. Animals raised on a defined artificial diet showed an increased preference (or decreased deterrence) for the lipid component (linolenic acid) of that diet in behavioural tests. Thus induction of preference was shown to be influenced by a specific nutrient compound. Fifteen artificial diets were tested; three were successful, including a completely defined medium. Various components of the diets were tested for feeding preferences, both as omissions from the main diet and as pure compounds. Some were stimulatory, most were neutral or slightly deterrent; a few were strongly deterrent. With the exception of linolenic acid, preferences for pure compounds were not significantly correlated with the food on which the animals were reared. The data suggest that food discrimination depends on the perception of a complex chemical message comprised of both polar and non-polar compounds, with the latter being of somewhat greater importance. The results are consistent with the explanation of the induction of feeding preferences being due to a reduced responsiveness to deterrents, to an increased preference for feeding stimulants or to both.     

Testing resource value in group-housed animals: an investigation of cage height preference in laying hens

To avoid unpredictable social effects, animals' behavioural priorities are almost always tested using individuals housed singly, yet many species kept commercially are social animals housed in groups. Our aim was to develop a method of investigating environmental preference in group-housed laying hens, Gallus gallus domesticus, that maximised the external validity of our findings. In a simple test of preference, eight groups of ten hens were given free choice between furnished cages with minimum heights of 38 cm (low) and 45 cm (high). A preference for one cage height over the other would be evident as a shift from a binomial distribution of flock sizes in the two cages. No height preference was found as hens distributed evenly between the two cages more frequently than was expected. This suggests at high stocking densities maximising average inter-individual distance could be a priority over increased cage height. In a second experiment, to investigate the value that hens placed on a change in cage height; a 'cost' in the form of a narrow gap was imposed on movement from a low or high start cage to a high or low target cage, respectively. Cage height did not influence the latency of the first three hens to enter the target cage. However, latencies for subsequent hens were shorter and more hens worked to access a high target cage than a low target cage. We suggest that titrating animals' willingness to tolerate higher stocking densities against access to a resource could be an effective way to compare responses of group-housed animals to resources that are expected to satisfy the same motivational state.     

Functional organization of a neural network for aversive olfactory learning in Caenorhabditis elegans

Many animals use their olfactory systems to learn to avoid dangers, but how neural circuits encode naive and learned olfactory preferences, and switch between those preferences, is poorly understood. Here, we map an olfactory network, from sensory input to motor output, which regulates the learned olfactory aversion of Caenorhabditis elegans for the smell of pathogenic bacteria. Naive animals prefer smells of pathogens but animals trained with pathogens lose this attraction. We find that two different neural circuits subserve these preferences, with one required for the naive preference and the other specifically for the learned preference. Calcium imaging and behavioral analysis reveal that the naive preference reflects the direct transduction of the activity of olfactory sensory neurons into motor response, whereas the learned preference involves modulations to signal transduction to downstream neurons to alter motor response. Thus, two different neural circuits regulate a behavioral switch between naive and learned olfactory preferences.     

Do Male Mice Prefer or Avoid Each Other's Company? Influence of Hierarchy,Kinship, and Familiarity

In the laboratory, individual housing of male mice who otherwise show aggression is common practice. Because mice are a social species, the question arises whether this procedure is right from the animals' point of view. This study tested the preference of subordinate animals for their dominant cagemate, and vice versa, and the preference of subordinate animals for an unknown subordinate partner. Experiments that allowed male mice with different histories to choose either an inhabited or an empty cage have shown that the mice preferred the proximity of another male over individual housing. No differences in this respect were found between dominant and subordinate males, or between littermates and nonlittermates. The preference was most obvious when mice who were previously housed together were tested. The study concludes that separation and single housing for mice are not attractive solutions for overcoming aggression in group-housed male mice and that alternative approaches, such as improving the housing conditions, should be explored as a way of tempering intermale aggression.     

The role of salivary androgen-binding protein in reproductive isolation between two subspecies of house mouse: Mus musculus musculus and Mus musculus domesticus

Previous behavioural studies using inbred lines have suggested that the gene ( Abpa ) for the alpha subunit of salivary androgen-binding protein (ABP) plays a role in prezygotic isolation between house mouse Mus musculus subspecies. We tested this hypothesis in animals from wild allopatric (121 individuals from four samples) and parapatric (320 animals from 15 samples) populations sampled on the Czech–Bavarian transect across the hybrid zone between M. m. domesticus and M. m. musculus . The study did not reveal a consistent statistically significant trend of homosubspecific preferences in individual allopatric and parapatric populations. Nonetheless, the whole pattern of preference was skewed toward homosubspecific preference mostly on the M. m. musculus side of the hybrid zone. The pattern of homosubspecific preferences was stronger for the time spent sniffing than it was for the first choice of the signal (the ratio of homosubspecific vs. heterosubspecific preferences for both sexes was 6 : 2 in allopatric and 21 : 9 in parapatric populations, while the same rates were 4 : 4 and 16 : 14 for the first choice). To the extent that Y-maze tests reflect preference under wild conditions, we suggest that this slight preference may not in itself be sufficient to impede gene flow between the two subspecies and thus act as a reproductive barrier. ABP most probably participates in a complex system of subspecies-specific recognition in the hybrid zone, but the picture is far too complex at this time to allow a conclusive evaluation of the importance of this role.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 84 , 349–361.     

Social behavior and gender in biomedical investigations using monkeys: studies in atherogenesis.

We review the use of socially housed cynomolgus monkeys (Macaca fascicularis) in biomedical research with emphasis on studies of atherosclerosis, particularly in the two specific domains of atherosclerosis investigation for which nonhuman primates are especially well-suited as animal models: gender differences and psychosocial influences. We found that the presence of normal ovarian function prevented exacerbation of diet-induced coronary artery atherosclerosis in female monkeys. However, any manipulation or condition which impaired ovarian function tended to diminish or abolish this "female" protection. Among group-housed female monkeys, low social status was accompanied by ovarian dysfunction and, not surprisingly, by exacerbated coronary artery atherosclerosis as well. Surgical menopause (ovariectomy) also induced exacerbation of coronary atherosclerosis in monkeys, a situation which was prevented by estrogen replacement therapy. Conversely, pregnancy (a hyperestrogenic state) resulted in markedly diminished atherosclerosis. A somewhat different pattern of atherogenesis emerged among socially-housed males. Here, socially dominant animals developed exacerbated coronary artery atherosclerosis, but only under conditions of social stress (viz., disruption caused by periodic reorganization of social group membership). We hypothesized that exposure to repeated group reorganizations provoked activation of the sympathetic nervous system among dominant animals; in turn, the hemodynamic and metabolic concomitants of sympathetic activation may have damaged the coronary arteries of these monkeys, potentiating atherogenesis. To test this hypothesis, males were housed in unstable social groupings, with half of the monkeys administered a beta-adrenergic blocking agent (to attenuate heart rate and blood pressure responses to stress). The beta-blocker inhibited atherosclerosis, but only among those animals behaviorally predisposed to develop exacerbated lesions (i.e. dominant monkeys). These results support the view that monkeys are suitable research models of atherosclerosis, a disease that affects millions of humans.     

Black lemur (Lemur macaco) hand preference in food reaching

The present study assessed the hand preferences exhibited by 33 black lemurs during routine feeding. Individual animals displayed hand preferences that were consistent across observations separated by as much as seven months. Within this population, 20 were left hand preferent, 12 right preferent, and 1 was ambidextrous. Correlational analysis of age and percentage left hand use indicated an inverse relationship in which younger animals tended towards the preferential use of the left hand and older animals the preferential use of the right hand. Similar analysis found no relationship between either sex and hand preference or familial relationship and hand preference. The skewed distribution of age in this sample renders tentative conclusions regarding age-related variations in hand preference. It is suggested that if the hand preferences of the black lemur are not age-related, then this species may be characterized as having a bias towards the preferential use of the left hand for food reaching.     

Group housing in row cages: an alternative housing system for juvenile mink

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.     

Behavioral thermoregulation in Hemigrapsus nudus,the amphibious purple shore crab

The thermoregulatory behavior of Hemigrapsus nudus, the amphibious purple shore crab, was examined in both aquatic and aerial environments. Crabs warmed and cooled more rapidly in water than in air. Acclimation in water of 16 degrees C (summer temperatures) raised the critical thermal maximum temperature (CTMax); acclimation in water of 10 degrees C (winter temperatures) lowered the critical thermal minimum temperature (CTMin). The changes occurred in both water and air. However, these survival regimes did not reflect the thermal preferences of the animals. In water, the thermal preference of crabs acclimated to 16 degrees C was 14.6 degrees C, and they avoided water warmer than 25.5 degrees C. These values were significantly lower than those of the crabs acclimated to 10 degrees C; these animals demonstrated temperature preferences for water that was 17 degrees C, and they avoided water that was warmer than 26.9 degrees C. This temperature preference was also exhibited in air, where 10 degrees C acclimated crabs exited from under rocks at a temperature that was 3.2 degrees C higher than that at which the 16 degrees C acclimated animals responded. This behavioral pattern was possibly due to a decreased thermal tolerance of 16 degrees C acclimated crabs, related with the molting process. H. nudus was better able to survive prolonged exposure to cold temperatures than to warm temperatures, and there was a trend towards lower exit temperatures with the lower acclimation (10 degrees C) temperature. Using a complex series of behaviors, the crabs were able to precisely control body temperature independent of the medium, by shuttling between air and water. The time spent in either air or water was influenced more strongly by the temperature than by the medium. In the field, this species may experience ranges in temperatures of up to 20 degrees C; however, it is able to utilize thermal microhabitats underneath rocks to maintain its body temperature within fairly narrow limits.     

Race Guides Attention in Visual Search

It is known that faces are rapidly and even unconsciously categorized into social groups (black vs. white, male vs. female). Here, I test whether preferences for specific social groups guide attention, using a visual search paradigm. In Experiment 1 participants searched displays of neutral faces for an angry or frightened target face. Black target faces were detected more efficiently than white targets, indicating that black faces attracted more attention. Experiment 2 showed that attention differences between black and white faces were correlated with individual differences in automatic race preference. In Experiment 3, using happy target faces, the attentional preference for black over white faces was eliminated. Taken together, these results suggest that automatic preferences for social groups guide attention to individuals from negatively valenced groups, when people are searching for a negative emotion such as anger or fear.     

Use of digitally modified videos to examine female mate preference for orange spot coloration of males in the guppy, Poecilia reticulata

Digitally modified video techniques may provide some advantages for the behavioral study of animals, including fishes. However, the validity of the experiments that are conducted using digitally modified videos should be verified. In the present study, we examined female mate preference in the guppy, Poecilia reticulata in a Japanese population by exploring an appropriate method involving the use of digitally modified video playbacks. For the male stimulus, two video images were produced by digital modification of a video recording of a male; the brightness of the orange spot coloration of the male was enhanced (bright male) in one video and decreased (dull male) in the other video. In experiment 1, female choice was examined according to the method described in previous studies, i.e., two monitors were set on opposite sides of the test aquarium to simultaneously present two stimulus male images to the females. However, in this experiment, the stimulus male images did not attract the females to a greater extent than the blank aquarium images. In addition, although the first trial showed a female preference for bright males, in the second trial, in which each stimulus male image was shown from the monitor opposite to that used in the first trial, a significant preference for bright males could not be detected. In experiment 2, a monitor was placed on one side of the aquarium and the left and right sides of the monitor showed the two stimulus male images simultaneously. In addition, a 24-h time interval was set between the first and second trials. Females spent more time in the proximity of the male images than that of the blank images, and a female preference for bright males was observed in both trials. The results of this study clearly indicate the female preference for males possessing bright coloration of orange spots. These results also suggest that the one-sided monitor system adopted in experiment 2 is a more appropriate method than the two-sided monitor system to examine female mate preferences by using digitally modified video playbacks.     

Handedness in the common marmoset (Callithrix jacchus)

For about 20 months the development of hand preferences in 21 experimentally naive common marmosets (Callithrix jacchus) was examined in 15 different tests. Test preferences were compared with their spontaneous behavior preferences in such contexts as feeding, grooming, play, and others. In the spontaneous use of the hands, only eight animals showed a significant lateral preference (2 left-handed, 6 right-handed). During the test period, however, the number of handed marmosets increased to 19 (5 left-handed, 14 right-handed). Most of the animals fluctuated considerably in their preference levels, a situation which led to a remarkable test response inconsistency of handedness. When the test situation was changed, complete reversals of handedness were more frequent than weakening or strengthening of a particular preference. The animals' emotions during the test session and environmental variables affected handedness significantly. None of the tested marmosets showed an increase of hand preference from the first to the last test. Our results indicate that Callithrix is ambidextrous rather than handed.     

Innate and learned components of human visual preference.

BACKGROUND: Recent claims in neuroscience and evolutionary biology suggest that the aesthetic sense reflects preferences for image signals whose characteristics best fit innate brain mechanisms of visual recognition. RESULTS: This hypothesis was tested by behaviourally measuring, for a set of initially unfamiliar images, the effects of category learning on preference judgements by humans, and by relating the observed data to computationally reconstructed internal representations of categorical concepts. Category learning induced complex shifts in preference behaviour. Two distinct factors - complexity and bilateral symmetry - could be identified from the data as determinants of preference judgements. The effect of the complexity factor varied with object knowledge acquired through category learning. In contrast, the impact of the symmetry factor proved to be unaffected by learning experience. Computer simulations suggested that the preference for pattern complexity relies on active (top-down) mechanisms of visual recognition, whereas the preference for pattern symmetry depends on automatic (bottom-up) mechanisms. CONCLUSIONS: Human visual preferences are not fully determined by (objective) structural regularities of image stimuli but also depend on their learned (subjective) interpretation. These two aspects are reflected in distinct complementary factors underlying preference judgements, and may be related to complementary modes of visual processing in the brain.     

VBA开发动物行为实时记录系统及实例

对动物行为进行实时记录是行为学研究的一项重要工作。传统的行为观察方法常常无法满足实时精确记录行为的要求 ,而一些现代的行为记录系统虽功能强大但却难以推广。作者应用VBA开发了一个简捷方便的行为实时记录系统 ,可以减少记录动物行为观察的工作量 ,降低记录动物行为的观察误差 ,保证了实验数据的可靠性。同时 ,该系统具有开放性和灵活性的特点 ,可以在不同动物行为研究中应用。