Stereotypies,aggression and the feeding schedules of tethered sows

Thirty tethered sows were observed for 5 min every half-hour for 9 h spanning the two feeding periods. Activity, consisting largely of food searching behaviour and drinking, was largely restricted to two 2-h periods following each feed. Three categories of stereotyped behaviour were observed and these were closely tied to the feeding periods. Short-duration bouts of rubbing, head-waving and bar-biting occurred during food delivery, while long-duration bouts of highly stereotyped and idiosyncratic sequences of rubbing and drinking were shown by older sows immediately after feeding. Vaccuum chewing tended to occur slightly later. I suggest that frustration of feeding motivation rather than under-stimulation underlies stereotypies in pigs, and that the different forms may represent stereotype of the appetitive and consummatory phases. Aggression was rare and was not closely related to the feeding periods or to stereotypies.     

Stereotyped behaviour,adjunctive drinking and the feeding periods of tethered sows

The behaviour of 25 tethered sows in an intensive piggery was observed for 1 h before and 1 h after the delivery of food to determine if behavioural stereotypies appeared as adjunctive behaviours. The different components of behavioural stereotypies were found to have different associations with the feeding period. Head-waving, bar-biting, and rubbing the snout against the cage were most common before feeding, and were shown particularly by the older sows. Manipulating the drinker and, for some sows, rubbing were most common after. There was some evidence of polydipsia. Vacuum chewing, playing with the chain, and aggressive behaviours, however, did not appear to be associated with the feeding period. The last two behaviours occurred only rarely. Seven sows showed stereotyped sequences of rapid rubbing or rapid drinking after the delivery of food, and these sows showed more excitement before food was delivered. Rooting was common for the full hour after all food had been consumed, and occurred in conjunction with long duration drinking. I suggest that the occurrence of adjunctive drinking by sows results from the persistence of feeding motivation, perhaps because concentrated food does not provide sufficient stomach distension, combined with the knowledge that food will definitely not be forthcoming. Stereotyped sequences of behaviour may be a means of reducing the arousal generated by the expectation of food.     

Antagonism of AP-5- and amphetamine-induced behaviour by timelotem as compared with clozapine and haloperidol

Bilateral intrastriatal injection of DL-2-amino-5-phosphonovaleric acid (AP-5), that blocks glutamatergic transmission at the N-methyl-d-aspartate preferring receptor, induces sniffing and body turns and reduces grooming in rats. Timelotem, a representative of the newly developed chemical class of anellated benzodiazepines antagonized specifically AP-5-induced sniffing and body turns. Classical (haloperidol) as well as atypical (clozapine) neuroleptics had recently been shown to antagonize AP-5-induced sniffing; clozapine, like timelotem, but not haloperidol, additionally antagonized AP-5-induced body turns. Further, timelotem antagonized amphetamine-induced stereotyped behaviour in rats, but was found less active than haloperidol in this test. Comparing the activity of drugs in both paradigms revealed that haloperidol inhibited AP-5-induced sniffing and amphetamine-induced stereotypies within the same dose range, but timelotem and clozapine were found more potent in the AP-5 test than in the amphetamine test. Thus, detailed drug profiles discriminate timelotem and clozapine from haloperidol, linking timelotem again to atypical antipsychotic compounds.     

Diurnal rhythm of bar-biting in relation to other behaviour in pregnant sows

Instantaneous observations of behaviour were made with video once every sixth minute around the clock (in 20-s recordings at each interval) during the first 3 days following the introduction of pregnant sows into one of the following three environments: (1) loose housing in groups of five with a common lying area, a dunging area and individual feeding stalls (20 sows); (2) semiconfinement in groups of four in individual feeding stalls with access to a common dunging area (16 sows); (3) confinement in individual stalls (16 sows). In addition, direct observations of straw-directed behaviour after feeding were made. Bar-biting was most frequent in confinement and least in loose housing (22.5% of observations when the sows were active in confinement, 7.5% in semi-confinement and 3% in loose housing). Bar-biting was mainly performed during ∼2 h following feeding. At the time when confined and semi-confined sows performed most bar-biting, the loose-housed sows moved a lot and performed complex straw-directed activities, including several of the normal nest-building behaviours. It was concluded that the differences in frequencies of stereotypies cannot be explained only by frustration at feeding, but depend on the housing system of the sows. Many of the movements in the stereotyped sequences of the confined sows resembled elements in the nesting sequences of loose-housed sows, supporting the hypothesis that a thwarted movement pattern can develop into a stereotypy, which then may bear resemblance to the normal movements.     

Stereotypies in polar bears

The spatial and temporal patterns of stereotypies in three captive polar bears (Ursus maritimus) were analysed. There was considerable variation in the time budgets of the three animals: stereotypies made up 16.0%, 24.4 %, and 76.5 % of the observation time between 8.00 A.M. and 4.00 P.M. Stereotyped walking or swimming bouts were of significantly longer duration than variable walking or swimming bouts. Seventy-five bouts of stereotyped walking were observed in detail to test the hypothesis that stereotypies can reduce arousal level. The bouts were composed of regular laps. At a given site, each lap consisted of a fixed number of steps, and there was little variation in the duration of a lap. In one individual the walking speed decreased significantly in the course of stereotyped walking bouts. Generally, however, stereotyped walking bouts were not preceded by high activity levels and followed by low activity levels. Stereotyped walking was regularly associated with yawning and tongue-flicking. Qualitative observations suggest that polar bears remain attentive while stereotyping. It is hypothesized that stereotyped walking in polar bears does not originate from frustrated migratory activity, but from frustrated appetitive behavior.     

Feeding motivation and stereotypies in pregnant sows fed increasing levels of fibre and/or food

Twenty-one multiparous sows were used in a Latin square design, from days 7 to 90 of gestation, to test the effect of fibre and food levels on feeding motivation and feeding-related stereotypies. Treatments were: VHF (very high-fibre, 29% ADF, 50% NDF, 4.5kg/day); HF (high-fibre, 23% ADF, 43% NDF, 3.5kg/day); C (control, 8% ADF, 20% NDF, 2.5kg/day); and control fed ad libitum (CAL). All diets except CAL provided a similar amount of major nutrients on a daily basis and were served in two meals. Each sow was subjected to each treatment for a 21-day period, at the end of which, behavioural observations were made. Two-hour observation periods starting at the afternoon food delivery revealed that sows spent more time eating on VHF and CAL (mean=21.2min) than on HF (13.2min) and C (7.6min) and more time on HF compared to C (p<0.01). When time spent eating was removed from total observation time, the percentage of remaining time spent in stereotypies was lower for VHF (median=17.9%) compared to C (median=49.8%), and lower for CAL (median=6.3%) compared to all other diets (p<0.01). During the period when lights were on (6.00-18.00h), 5min interval scans showed that VHF sows spent more time lying down and less time standing than C sows (p<0.05). Also, CAL sows spent more time lying down than sows on other treatments (p<0.01). During operant conditioning tests (OCT) performed before the afternoon meal and after the morning meal, less rewards were obtained by CAL sows (p<0.01), with no difference between other treatments. In conclusion, no reduction in feeding motivation of sows fed high-fibre diets could be measured by OCT, but very high levels of fibre were effective at reducing stereotypies and activity during the 2h post-feeding. However, these effects were not as marked as those observed with ad libitum feeding.     

Kicking,rocking, and waving: Contextual analysis of rhythmical stereotypies in normal human infants

I analysed the triggering contexts of over 14 000 bouts of rhythmical stereotypies of the legs, arms, and whole torso observed in 20 normal infants during their first year. Infant stereotypies were elicited by a wide variety of contexts including non-alert states, interactions with the caregiver and other persons, feeding situations, object interest, and kinaesthetic changes. The frequency of stereotypy in all contexts was a function of age. Non-alert states and interactions with the caregiver were disproportionately associated with leg and torso stereotypies. The relationship between these human stereotypies and the function and control of stereotyped behaviour in other species is discussed.     

The effect of lithium on chronic haloperidol enhanced apomorphine aggression in rats

The effect of chronic haloperidol or haloperidol plus lithium on apomorphine-induced aggressive and stereotyped behaviors was assessed. Rats withdrawn from chronic haloperidol treatment showed increased aggressiveness and had an increased duration of stereotyped behavior. Rats treated chronically with haloperidol in combination with lithium did not display a supersensitive response. These findings are discussed in relation to the results of other investigators.     

On-farm evaluation of methods to assess welfare of gestating sows

The objectives were to evaluate quantitative animal-based measures of sow welfare (lameness, oral stereotypies and reactivity to humans) under commercial farm conditions, and to estimate the influence of housing, sow parity and stage of gestation on the outcome of these measures. Across 10 farms, 311 sows were used. Farms differed in terms of housing design (pen v. stall), space allowance, floor type in stalls (partially v. fully slatted), and feeding system in pens (floor v. trough). Lameness was assessed in terms of gait score, walking speed, stride length, stepping behaviour, response to a stand-up test and latency to lie down after feeding. The presence of oral stereotypies and saliva foam were recorded. Reactivity to humans was assessed by approach (attempt to touch the sow between the ears) and handling tests (exit of the stall for stall-housed sows, or isolation of the animal for pen-housed sows). Only stride length and walking speed were associated with lameness in stall-housed sows (P<0.05 and P<0.01). In stalls, the probability that a sow was lame when it presented a short stride length (<83 cm) or a low speed (<1 m/s) was high (69% and 72%, respectively), suggesting that these variables were good indicators of lameness, but were not sufficient to detect every lame sow in a herd (sensitivity of 0.39 and 0.71, respectively). The stage of gestation and parity also influenced measures of stride length and walking speed (P<0.05). Saliva foam around the mouth was associated with the presence of sham chewing and fixture biting (P<0.05). The probability that a sow presents sham chewing behaviour when saliva foam around her mouth was observed was moderate (63%) but was not sufficient to detect all sows with stereotypies (41%). A high discrimination index was obtained for behavioural measures (aggressions, escapes) and vocalisations during the approach test (stalls: 78.0 and 64.0; pens: 71.9 and 75.0, respectively), the number of interventions needed to make the sow exit the stall during the handling test for stall-housed sows (74.9), and attempts to escape during the handling test for pen-housed sows (96.9). These results suggest that these measures have a good power to discriminate between sows with low and high reactivity to humans. Finally, the outcome of several measures of lameness, stereotypies and reactivity to humans were influenced by the housing characteristics, sow parity and stage of gestation. Therefore, these factors should be considered to avoid misinterpretations of these measures in terms of welfare.     

Stereotypy and dyskinesias provoked in cats differentiate directly and indirectly-acting psychomotor stimulants

Cats were observed after treatment with different doses of d-amphetamine, apomorphine, piribedil, nomifensine and L-DOPA + benserazide. Nomifensine (30 mg/kg, ip), d-amphetamine (3, 5 and 7.5 mg/kg, ip) and L-DOPA (100 mg/kg, ip) induced stereotyped behaviors without a significant increase in dyskinetic movements. Piribedil (80 and 150 mg/kg, ip) induced dyskinetic movements without stereotypies. Apomorphine (3 and 10 mg/kg, ip) induced a high frequency of dyskinetic movements with stereotypies occurring only at the highest dose level (10 mg/kg). The dissociation between the stereotyped behaviors and dyskinesias induced by psychomotor stimulants parallels the distinction between indirect and direct receptor stimulation.     

Effect of haloperidol, suckling, oxytocin and hand milking on plasma relaxin and prolactin concentrations in cyclic and lactating pigs

Prolactin secretion was stimulated in 5 cyclic gilts during the luteal phase (Day 10-13) with 5 mg haloperidol given i.v. Stimulation of prolactin secretion was also attempted by inducing milk let-down by suckling (4 sows), or by the injection of 1 mg oxytocin i.v. followed by hand milking (3 sows). Plasma prolactin concentrations increased significantly 1-2 h after haloperidol injection, and in 3 of 4 sows during suckling (P = 0.001); plasma relaxin concentrations did not change significantly at these times. No change was observed in plasma prolactin or relaxin concentrations at 15 min or 1-2 h after oxytocin injection and hand milking. Plasma relaxin concentrations ranged from below the sensitivity of the assay (100 pg/ml) to 450 pg/ml in lactating sows and from 100 to 2000 pg/ml in cyclic gilts. The results suggest that in cyclic gilts treated in the luteal phase with a dopaminergic receptor blocker, and in lactating sows during suckling, elevations in plasma prolactin concentrations were not accompanied, during the same period, by detectable changes in relaxin concentrations.     

Maternal behaviour in sows of different social rank

The maternal behaviour of domestic sows in intensive husbandry has been studied in relation to their social rank during the second half of pregnancy when they were kept in groups. The sows dominant during pregnancy were more active immediately before farrowing but not after it. The low-ranking sows showed much more restlessness from the early days after farrowing and many stereotyped/redirected patterns. Those sows voluntarily interrupted nursing in the early days of lactation more often, while the dominant sows were more likely to allow piglets to suckle freely.     

Effects of dopaminergic agonists and antagonists on cerebellar guanosine-3',5'-monophosphate (cGMP).

Apomorphine was found to cause an increase in cerebellar cGMP content. Bromocriptine, at a dose that caused stereotypies, neither elevated cGMP, nor blocked the apomorphine- induced rise in cGMP. The apomorphine-induced rise in cGMP was effectively blocked by haloperidol and some other neuroleptics, but not by sulpiride. These actions of the neuroleptics correlated with their ability to displace ³H-spiroperidol from striatal membranes, suggesting that dopamine receptor interactions were important in the cGMP changes noted. Based on the observation that haloperidol antagonized the increase induced by restraint, it is suggested that dopaminergic systems are involved in the reaction to stress.     

Antagonism of AP-5-induced sniffing stereotypy links umespirone to atypical antipsychotics.

Blockade of glutamatergic transmission in the striatum (using the NMDA-antagonist DL-2-amino-5-phosphonovaleric acid AP-5) was recently shown to induce stereotyped sniffing in rats. Comparable stereotyped behaviour is well known to be elicited by stimulation of dopamine activity, which since long was the basis for experimental models to check for possible antipsychotic activity of new compounds. However, whereas dopamine-induced stereotypies are antagonized only by classical neuroleptics, stereotypies induced by blockade of glutamatergic transmission are antagonized by classical as well as by atypical antipsychotics. Umespirone, a novel psychotropic which has been reported to exhibit behavioural effects predictive for antipsychotic as well as anxiolytic potential was evaluated for antagonistic effects against AP-5-induced behaviour. The profile of umespirone was compared with the profile of a non-benzodiazepine anxiolytic buspirone as well as with previously published data of neuroleptics. Umespirone like clozapine specifically antagonized AP-5-induced sniffing, i.e. did not impair spontaneous sniffing but reversed AP-5-induced excessive sniffing. In contrast, buspirone impaired spontaneous and AP-5-induced sniffing to about the same extend. These results are in accordance with the glutamate hypothesis of schizophrenia and again give evidence that umespirone should have antipsychotic potential and a very low liability to exhibit unspecific sedative action.     

Phencyclidine-induced stereotyped behavior and serotonergic syndrome in rat

Phencyclidine (50 mg/kg, i.p.) induced in rats a biphasic response consisting of serotonergic syndrome followed by stereotyped behavior. The initial serotonergic syndrome was significantly reduced by cinanserin (20 mg/kg, i.p.) and cyproheptadine (2.0 mg/kg, i.p.) but not influenced by haloperidol (0.5 mg/kg, i.p.). The later stereotyped behavior was significantly reduced by haloperidol (0.5 mg/kg, i.p.) but not influenced by cinanserin (20 mg/kg, i.p.) or cyproheptadine (2.0 mg/kg, i.p.). A lower dose of phencyclidine (5.0 mg/kg, i.p.) elicited only haloperidol-sensitive stereotyped behavior. These results indicate that serotonergic and dopaminergic mechanisms may mediate the behavioral effects of phencyclidine in rats.     

Decreased antistereotypic effect of neuroliptics after additional treatment with a benzodiazepine, a GABA agonist or an anticholinergic compound.

Neuroleptics are very potent antagonists against stereotypies induced by DA-stimulants including methylphenidate. This effect of neuroleptics is usually related to the antipsychotic effect of these compounds. In contrast we found that GABA agonists potentiate stereotyped gnawing induced by methylphenidate. The GABA agonist muscimol in combination with neuroleptics will attenuate the antagonistic effect of these compounds on stereotyped gnawing induced by methylphenidate. However a differentiation between the neuroleptic drugs was found: Haloperidol, spiroperidol and pimozide were profoundly antagonized by muscimol whereas cis(Z) - flupenthixol and fluphenazine were less antagonized. Baclofen shows no significant effect. Diazepam and scopolamine also strongly antagonized the antistereotypic effect of the butyrophenone-like compounds whereas only scopolamine could antagonize fluphenazine and cis(Z) - flupenthixol. Therefore we conclude that if the antistereotypic effect of neuroleptics correlates to the antipsychotic effect, a GABA agonist would probably not potentiate the antipsychotic effect of neuroleptics but rather antagonize it.     

Phencyclidine-induced stereotyped behavior in rats: dose response effects and antagonism by neuroleptics.

Phencyclidine hydrochloride produced a very characteristic and reproducible stereotyped behavioral syndrome in rats. Both the intensity and the duration of the phencyclidine-induced stereotyped behavior are elicited in a dose-dependent manner in the 2–16 mg/kg dose range. The predominant behavior elicited by low doses was repetitive lateral head swaying, while with higher doses circling and backward walking were observed in addition to the head swaying. This behavior was antagonized by the neuroleptic agents chlorpromazine, haloperidol, and pimozide, but not by α- or β-adrenergic blockers. These results indicate that the phencyclidine-induced stereotyped behavior may be mediated by central dopaminergic mechanisms.     

Behavioral evidence for supersensitivity after chronic administration of haloperidol,clozapine, and thioridazine

Rats administered chronic neuroleptics for 6–7 weeks-- haloperidol (2.5 mg/rat or 1 mg/kg), clozapine (25 mg/kg), or thioridazine (20 mg/kg)--after termination of chronic drug treatment exhibited greater apomorphine-induced stereotyped behavior than their saline controls. Rats treated with thioridazine or clozapine, but not haloperidol, also showed increases in locomotor activity during withdrawal. These findings indicate that behavioral supersensitivity may develop after chronic clozapine treatment as well as after chronic haloperidol.     

Effects of melatonin on behavioral dopaminergic supersensitivity

This study examines the effects of melatonin on dopaminergic supersensitivity induced by long-term treatment with haloperidol in rats. Enhancements of spontaneous general activity in an open-field and of stereotyped behavior induced by apomorphine after abrupt withdrawal from long-term treatment with haloperidol were used as experimental parameters for dopaminergic supersensitivity. Experiment 1 was conducted to investigate the effects of melatonin on the development of dopaminergic supersensitivity, and experiment 2 was conducted to investigate the effects of melatonin on the development as well as on expression of dopaminergic supersensitivity. Rats of both experiments were long-term treated with saline or haloperidol concomitant to saline or melatonin. In experiment 1 behavioral observations were performed after abrupt withdrawal from long-term treatment. In experiment 2 behavioral observations were performed 1 hour after an acute injection of saline or melatonin, administered after the abrupt withdrawal from long-term treatment. Both behavioral parameters used showed the development of central dopaminergic supersensitivity in rats treated with haloperidol since 24 hours after abrupt withdrawal. Concomitant treatment with melatonin intensified haloperidol-induced dopaminergic supersensitivity, observed 72 hours after withdrawal. Melatonin treatment per se also induced behavioral supersensitivity evaluated by both open-field and stereotyped behaviors, although it was more fugacious than that presented by haloperidol. Acute treatment with melatonin reverted the enhancement of the haloperidol-induced dopaminergic supersensitivity produced by concomitant long-term treatment with melatonin, as well as melatonin-induced dopaminergic supersensitivity per se. Our results support previous evidence of antidopaminergic effects of melatonin and demonstrate that repeated administration of this hormone modifies the plasticity of behaviors mediated by central dopaminergic systems.     

The D2 autoreceptor agonists SND 919 and PD 128483 decrease stereotypy in developing rats

Although stereotyped behavior in adult rats is partly regulated by dopamine (DA) D2 autoreceptors, previous attempts to demonstrate D2 autoreceptor regulation of stereotypy in developing rats have been unsuccessful. In the present study, two highly selective D2 autoreceptor agonists were used to demonstrate D2 autoreceptor regulation of spontaneous stereotyped behavior in developing rats. Both SND 919 and PD 128483 produced significant dose-dependent decreases in the stereotypy counts of 21-day-old, 35-day-old, and adult rats. There was a 51% decrease in the stereotypy counts of 21-day-old rats injected with SND 919, 0.05 mg/kg, compared to a 36% decrease in the counts of rats pretreated with haloperidol. Similarly, PD 128483 significantly decreased the stereotypy counts of 21-, 35-day-old, and adult rats in a dose-dependent fashion. There was a 58% decrease in the stereotypy counts of 21-day-old rats injected with PD 128483, 0.1 mg/kg, compared to a 17% decrease in counts when the rats were first treated with haloperidol. The effect of haloperidol plus PD 128483 was significantly different from the effect of PD 128483 alone. Injection of SND 919 or PD 128483 had no significant effects on the stereotypy counts of 10-day-old rats. The results suggest that DA D2 autoreceptor-mediated regulation of spontaneous stereotyped behavior is functional at 21, but not 10, days of age.