Suzanne D E Held

Animal play and animal welfare

Play has long been identified as a potential welfare indicator because it often disappears when animals are under fitness challenge and because it is thought to be accompanied by a pleasurable emotional experience. But animal play is a vexing behavioural phenomenon, characteristically flexible and variable within and between species, with its proximate mechanisms and ultimate functions still not fully understood. Its relationship to animal welfare is therefore complex and merits a focused theoretical investigation. We review evidence on four aspects of the play–welfare relationship: first, that play indicates the absence of fitness threats; second, that play acts as a reward and flags up the presence of opioid-mediated pleasurable emotional experiences; third, that play brings immediate psychological benefits and long-term fitness and health benefits, and thus improves current and future welfare; and finally, that play is socially contagious and therefore capable of spreading good welfare in groups. On this basis, we argue that play does indeed hold promise as a welfare indicator and also as a tool to improve it; but we also point to difficulties in its study and interpretation, and identify some unresolved questions. As a welfare indicator, play may signal both the absence of bad welfare and the presence of good welfare, thus covering a wide range of the welfare spectrum. However, play can also increase in stressful situations, in response to reduced parental care, or as a rebound after a period of deprivation and therefore does not consistently reflect favourable environmental conditions. A better fundamental understanding is needed of the varied ultimate functions and proximate mechanisms of play, and the species-specific play patterns of captive animals, in order to be able to explain exactly what an animal’s play behaviour tells us about its welfare state, and whether and how play might be applied as a tool to improve welfare.

A cohort study of preweaning piglet mortality and farrowing accommodation on 112 commercial pig farms in England

A cohort study was carried out on 112 breeding pig farms in England to investigate the impact of type of farrowing accommodation on preweaning mortality in piglets. Four types of farrowing accommodation were studied; farrowing crates, indoor loose pens, crate/loose systems (where the sow was restrained in a crate during birth and the first days of lactation before being moved to a loose pen) and outdoor farrowing in arcs in paddocks. Four estimates of preweaning mortality were collected: an oral estimate from the farmer before the visit, an estimate from the 6-month rolling average from computer records, records from 20 litters observed when the farm was visited and prospective records collected from 20 farrowings after the visit. These four estimates were significantly correlated. The prospective records also included a farmer reported date and cause of death. From the prospective data there were 25,031 piglets from 2143 litters from 112 farms, 6.5% of piglets were stillborn while live born preweaning mortality was 12%. Mixed effect discrete time survival, binomial and competing risk, models were used to investigate the association between preweaning mortality and farrowing accommodation, controlling for sow parity, litter size and number of piglets stillborn and fostered. There was a reduced risk of stillbirths in outdoor farrowing systems compared with crated systems. Farmers reported that crushing of healthy piglets was the most frequent cause of death accounting for 55% of live born preweaning mortality. There was no significant difference in mortality in live born piglets by farrowing system. There was a significantly higher risk of farmer reported crushing of healthy live born piglets in outdoor arcs compared with piglets reared with sows in farrowing crates and a significantly reduced risk of death from causes other than crushing in piglets reared outdoors or in crate/loose systems compared with piglets reared in crated systems. We conclude that, in the farms in this study, farrowing crates reduced the risk of preweaning live born mortality attributable to crushing but piglets in this system were at increased risk of death from other causes. Consequently crates had no significant effect on overall preweaning mortality percentage. In all four commercial production systems; outdoor, farrowing crates, crate/loose farrowing systems and indoor loose housed systems, there were similar levels of mortality.

Foraging pigs alter their behaviour in response to exploitation

Abstract When food finders are exploited by others, but cannot themselves switch to scrounging or leave their foraging group, other behavioural adaptations should be favoured. Tactical deception in primates and foraging at the periphery of the group in ground-feeding birds have been suggested as two such responses. We show that exploited individuals may also respond by adjusting their foraging behaviour to the concurrent behaviour of the scroungers. We investigated the foraging strategies of exploited subordinate domestic pigs, Sus scrofa . Pairs of pigs were tested in competitive foraging trials. We trained the subordinate pig in each pair to use a producing tactic in competitive pair trials by informing it about the location of hidden food during a preceding search trial in which it foraged alone. The dominant pig was naive about the food location in the competitive trials but able to displace the subordinate from the food source. We have shown previously that the dominants scrounged on their coforagers in these competitive trials by following them and displacing them from the food source. In the present study, logistic regression analyses show that the food-finding subordinates altered their foraging behaviour depending on the current behaviour of the dominants. Overall, the subordinates were more likely to show food-directed behaviour when the chances of arriving at the food source ahead of their exploiters were higher. The foraging behaviour of individual subordinates was related to their exploitation experience. Individuals subjected to higher exploitation pressure showed more varied strategies. These behavioural strategies are most simply interpreted as attempts by the exploited food finders to increase the time they can spend at the food source before the scroungers arrive. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved .

Foraging behaviour in domestic pigs ( Sus scrofa ): remembering and prioritizing food sites of different value

This experiment investigated whether domestic pigs can remember the locations of food sites of different relative value, and how a restricted retrieval choice affects their foraging behaviour. Nine juvenile female pigs were trained to relocate two food sites out of a possible eight in a spatial memory task. The two baited sites contained different amounts of food and an obstacle was added to the smaller amount to increase handling time. On each trial, a pig searched for the two baited sites (search visit). Once it had found and eaten the bait, it returned for a second (relocation) visit, in which the two same sites were baited. Baited sites were changed between trials. All subjects learnt the task. When allowed to retrieve both baits, the subjects showed no preference for retrieving a particular one first (experiment 1). When they were allowed to retrieve only one bait, a significant overall preference for retrieving the larger amount emerged across subjects (experiment 2). To test whether this preference reflected an avoidance of the obstacle with the smaller bait, 15 choice-restricted control trials were conducted. In control trials obstacles were present with both baits. Pigs continued to retrieve the larger bait, indicating they had discriminated between the two food sites on the basis of quantity or profitability and adjusted their behaviour accordingly when the relocation choice was restricted. This suggests for the first time that domestic pigs have the ability to discriminate between food sites of different relative value and to remember their respective locations.

Effects of litter size, sex and periconceptional ewe nutrition on side preference and cognitive flexibility in the offspring

Maternal undernutrition during pregnancy alters the physiology, behaviour and cognitive abilities of the offspring in sheep. Undernutrition restricted to the time around conception alters the physiology of the offspring, but effects on the behaviour and cognitive abilities are unknown. We studied the effects of mild periconceptional undernutrition in sheep on side preference and cognitive flexibility in the offspring. Ewes were well fed (controls) or mildly undernourished from 60 days before until 30 days after mating (PCUN; 10-15% body weight reduction). Offspring were evaluated at 4 and 18 months of age in a left-right choice maze using social and feeding motivation as rewards. We determined side preference, and assessed cognitive flexibility as the ability to improve runs required to reach criterion during two reversal learning episodes. Side preference in the PCUN offspring was close to neutrality in singleton males (p < or = 0.05) and twin females (p < or = 0.05) at 4 but not 18 months of age. Twin offspring tended to be more likely to change side preference between 4 and 18 months (p=0.07). Performance on reversal learning was similar in PCUN and control offspring, but speed of learning improved faster in female than in male lambs (p < or = 0.05) at 4 but not 18 months of age. These findings suggest that mild periconceptional undernutrition in sheep can alter behavioural laterality of the offspring, and that singleton/twin status, sex and postnatal age are all important factors to consider in evaluating the effects of prenatal insults on postnatal behaviour.

Factors associated with preweaning mortality on commercial pig farms in England and Wales

Data from 67 pig farms with a variety of farrowing systems were used to identify factors associated with preweaning mortality in British pig herds. The median mortality reported by the farmers was 10·7 per cent (interquartile range 8·5 to 14 per cent). There was a significantly higher mortality when the pigs were weaned when they were older. A multivariable Poisson model was developed into which the types of farrowing system on each farm and the age at weaning were forced. Factors associated with a lower preweaning mortality rate were insulating the farrowing building, providing extra heat at farrowing, giving the piglets iron injections, dipping their navels, using fan ventilation and using artificial lighting systems. Factors associated with a higher mortality rate were a later weaning age, the use of infra-red lamps rather than other forms of supplementary heat, and the use of a creep without any bedding.

Effects of environmental enrichment and loose housing of lactating sows on piglet performance before and after weaning

We investigated effects of loose housing of the sow during lactation and enrichment of the pen pre- and postweaning on performance of newly weaned piglets. Before weaning, piglets (n = 320) were housed in an enriched (straw, wood shavings, peat, and branches) or barren pen with a confined or loose-housed sow (n = 32). Loose-housed sows and their piglets could eat together from a family feeder, whereas confined sows and piglets had separate feeding troughs. Piglets (n = 256) were mixed postweaning, and 4 piglets from each litter were relocated to a barren pen (n = 32 pens) and 4 other piglets were housed in an enriched pen (n = 32 pens). Growth from d 15 until weaning was greater for piglets from enriched pens (4.38 ± 0.29 vs. 4.71 ± 0.21 kg/pig, P < 0.05) and tended to be greater for piglets with a loose-housed sow compared with piglets with a confined sow (4.41 ± 0.26 vs. 4.67 ± 0.24 kg/pig, P = 0.10). Preweaning feed intake was not affected by preweaning conditions (P > 0.25). Piglets from enriched preweaning pens ate more in the first 2 d postweaning than piglets from barren pens (first 48 h, barren 0.45 ± 0.05 kg/pig, enriched 0.53 ± 0.04 kg/pig, P < 0.05). Piglets relocated to an enriched pen after weaning showed a greater growth in the 2 wk after weaning (barren 5.5 ± 0.2 kg/pig, enriched 6.2 ± 0.2 kg/pig, P < 0.0001), had a profoundly reduced diarrhea prevalence than piglets housed in barren pens after weaning (barren 2.4 ± 0.4 d, enriched 1.0 ± 0.3 d, P < 0.0001), and had a greater feed efficiency (barren 0.81 ± 0.03, enriched 0.85 ± 0.02, P < 0.05). Enrichment of the preweaning environment likely stimulates development of feeding behaviors and consequently increases feed intake immediately after weaning. Providing piglets with an enriched environment after weaning positively affected postweaning growth, feed efficiency, and incidence of diarrhea, which may be caused by decreased stress or increased gut health. Enrichment of the pre- and postweaning environment seems important in improving performance and health of newly weaned pigs.

Domestic pigs, Sus scrofa, adjust their foraging behaviour to whom they are foraging with

Subordinate domestic pigs show behavioural tactics similar to the ones described as tactical deception in primates and corvids when foraging with scrounging dominants for a single monopolizable food source. Here we investigated further whether they can learn deceptive tactics to counter a scrounger by first retrieving the smaller of two hidden food baits, and whether they can discriminate between different types of co-forager. Seven subordinate pigs were tested with co-foragers, and also alone, when foraging for two differently sized food baits hidden in two of 12 buckets in a foraging arena. Unlike their co-foragers, the subordinates already knew where the foods were located; co-foragers differed in whether they were scroungers or not. Subordinates did not respond to scrounging with the predicted deceptive tactic of visiting the small bait first. They did, however, lose their overall preference for retrieving the large bait first and increased their foraging speed compared to when foraging with nonscroungers or on their own. The findings suggest the ability to discriminate between different individual co-foragers in domestic pigs, and increasing foraging speed as a way of responding to exploitation by scrounging dominants in competitive foraging situations with several food patches.

The current state of welfare, housing and husbandry of the English pet rabbit population

BackgroundThe welfare of pet rabbits is an area of growing interest in Europe and the UK. This study analyses questionnaire results from a diverse population of 1254 rabbit owners from three different geographical areas in England with the aim of providing an accurate representation of how pet rabbits are currently housed and cared for and key aspects of their health and welfare.ResultsRabbits were kept in a variety of different housing types, the most common being a traditional hutch/cage (59%). Although the majority had additional exercise areas, access was often unpredictable, or ill-timed, which may compromise welfare. Only 41.9% of owners kept their rabbit with conspecifics, limiting their ability to engage in social behaviour. Of those rabbits housed with a companion, although many were reported to be amicable and to engage in positive interactions, over a quarter were reported to fight at least occasionally (25.3%), whilst 22.7% guarded resources and 27.1% avoided one another. Whilst low levels of some of these behaviours may be a normal part of social interaction, the relatively high levels reported here suggest that not all cohabiting pairs of rabbits are compatible, which is potentially a significant welfare issue.Although the vast majority of owners fed hay for over 10% this was less than daily. Pelleted foods were very popular (71.4% at least daily) compared to commercial muesli mixes (32.6%). As in previous studies, dental problems were commonly reported (12.2% of rabbits); however, so were eye problems (12.9%), digestive problems (11.5%) and parasites (11.3%). A large proportion of rabbits (58%) were thought to be fearful of loud noises, and 61% were not reported as calm when handled by their owner, which may be a significant concern for this species.ConclusionThis study has confirmed and expanded on previous findings: many pet rabbits were found to be in good health, had compatible companions and were provided with enriched living areas. However, it also found numerous welfare issues that affect large numbers of pet rabbits. We suggest further studies are required exploring the accuracy of owner reports (which possibly under-report many problems) and prioritising the issues raised here.

Advances in the Study of Cognition, Behavioural Priorities and Emotions

Ask a human being how it is faring and chances are it will report on its state of mind. Ask a pig how it is faring and chances are that this direct verbal approach will not get you very far. Two important points are thus illustrated for our purposes here. Firstly, for most people the notion of ‘faring well’ or ‘welfare’ is inextricably linked to state of mind or ‘mental state’ (reviews in Broom, 2001; Dantzer, 2001; Dawkins, 2001; see also Duncan and Petherick, 1991). The second point is that where we aim to study the welfare of animals, we have to use non-verbal expressions or correlates of their mental state. Our aim in this chapter is to provide an overview of how different aspects of the ‘mind’ of pigs have been studied and what these studies have shown. The studies have been loosely grouped into three sections with some inevitable overlap between them. The first section explores pigs’ cognitive abilities. In our usage here, ‘cognitive’ is a collective term for all the mental processes which pigs may use to perceive, handle and store environmental information (cf Shettleworth, 2001). As such, it covers the pigs’ sensory capacities, their learning and memory abilities, and other abilities which may go beyond associative learning of simple reward contingencies. We then turn to what pigs may ‘want’ to do or be motivated to get, and how this can be studied. Finally, we review ways in which emotions in general, and pig emotions in particular, might be studied.