Conference Paper

Should Zoo Food be Chopped?

  • Wild Planet Trust
  • Bumblebee Conservation Trust
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The food provided for many zoo animals is chopped into small pieces even if the animals are capable of processing much larger items. Chopping food takes time and the chopped edges increase the risk of bacterial contamination and food spoilage; whereas leaving food whole may allow the animals to express more natural feeding behaviour and increase their food processing time. So why do keepers chop food? Reasons offered are: [1] It enables all individuals in a group to obtain enough of each food type and reduces aggression; [2] It prevents wastage caused by animals taking one bite and discarding the rest of a large item; [3] It enables a wider scatter feed to encourage foraging behaviour and prolong feeding time. We investigated these assumptions in two species, Sulawesi crested black macaque (Macaca nigra) and Brazilian tapir (Tapiris terrestris). The usual fruit and vegetable feed provided to each group was offered in four conditions: chopped/clumped, chopped/scattered, whole/clumped and whole/scattered, such that the total amount of food was the same on each day. The average piece size and total weight of each produce type was recorded each day and any food uneaten each day was weighed. Each study subject was observed individually during feeding time and the number and type of each food item eaten recorded, along with any aggression and their total time spent feeding. Each subject was also observed for two 30 minute sessions at other times throughout the day and their behaviour recorded using instantaneous sampling every minute. The data were analysed using randomisation tests equivalent to two-way ANOVAs to determine the effects of food item size and presentation method on total weight of food consumed, diversity of food items consumed, total feeding time, aggression during feeding, behaviour throughout the day and total food wasted. These results indicate that the supposed advantages of chopping food are not actually evident. For the macaques food size and presentation did not significantly affect any of the variables measured when considering all subjects. However the most subordinate individual was able to obtain significantly more food (randomisation test, P = 0.008) when food was left whole rather than chopped (scattering or clumping the food made no difference). For the tapirs the only statistically significant effect was found at one of three zoos where the chopped/clumped condition resulted in significantly less foraging behaviour throughout the day than the whole/clumped condition (randomisaton test, P = 0.013). Therefore chopping food does not seem to have any of the advantages keepers suggest and we recommend that if animals are capable of processing it food should be provided whole to avoid the increased risk of contamination and nutrient loss and save keeper time.

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... A well-presented diet may allow animals to have opportunities to express aspects of their natural behavior and to engage in rewarding activity [7,8]. The impact of zoo food presentation styles has already been explored by some authors [9,10]. However, there are opportunities to further diversify the presentation styles and species being investigated. ...
... It is well known that food preparation and presentation can have an impact on animal behavior [9][10][11][12][13][14][15]. However, other aspects of food presentation have not been considered in detail in the zoological setting. ...
... To differentiate between preparation and presentation, we define food presentation as the placement of the food once it is in the animal's enclosure. Food presentation styles include containers such as troughs, bowls, and tins; scatter feeds [9]; placement in enrichment feeders; or impalement on enclosure furnishings [8]. ...
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From its foundations in agricultural science, zoo animal nutrition has developed into a biologically informed, evidence-based discipline. However, some facets of nutrition still make use of a more traditional approach, such as the field of zoo presentation. For example, it is common practice to prepare animal diets by chopping them into bite-size chunks, yet there is limited peer-reviewed evidence that explains the benefits and welfare implications of this practice. The chopping and placement of foods can alter desiccation rates, nutrient breakdown, and food contamination, so it is important to evaluate the implications of current practices. Here, the published literature on the behavioral impacts of different food presentation formats (such as clumped and scattered, and chopped and whole) is reviewed, with reference to a range of taxa. The current state of knowledge of the nutritional and microbiological effects of food presentation practices are also reviewed. Relevant research is available on the behavioral effects of some forms of zoo food presentation; however, relatively little research has been conducted on their nutrient composition effects or desiccation rates. Similarly, there are gaps in terms of the species that have been investigated, with a few mammalian taxa dominating the food presentation literature. Future research projects covering social, behavioral, and welfare impacts, and the nutritional and microbiological consequences of food presentation would further evidence-based zoo and aquarium management practices. Similarly, qualitative research surrounding keeper perception of food presentation formats would help to identify challenges and opportunities in this field.
... A study on rhesus macaques (Mathy and Isbell, 2001) found that chopped foods decreased aggression and increased foraging duration. Furthermore, chopped diets require increased food preparation time for zookeepers (Plowman et al., 2009) and are more prone to desiccation and contamination (Rico et al., 2007). Also, food for wild animals is unlikely to be presented in bitesize chunks, and many species possess specific food handling behaviours (Mathy and Isbell, 2001). ...
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The white-naped mangabey is an endangered and rare zoo species, yet little is known concerning their welfare in captivity. The assessment of welfare should incorporate a net balance of negative and positive welfare behavioural indicators. These behaviours, and thus welfare, can be affected by the way food is presented based on its distribution, clumped or dispersed, and its size, chopped or whole. This study investigated the effect of food presentation on time-budget behaviours (i.e. forage, activity, inactivity, allogroom, self-groom, play) and stress-related measures (i.e., diarrhoea, aggression, self-directed behaviours), in four crossed-over test conditions of food distribution. The group-living mangabeys of Rotterdam Zoo were provided with vegetables that differed in distribution and size: clumped-chopped, dispersed-whole, dispersed-chopped, and clumped-whole. Mangabeys spent least time being inactive and subordinates and juveniles spent most time foraging during the dispersed-chopped condition, while the reversed was found during the clumped-whole condition. In addition, mangabeys stole food more often and engaged in less self-directed behaviours during dispersed-chopped, compared with dispersed-whole. In contrast, food distribution and size did not affect aggression, play, activity, self-grooming and diarrhoea. Consistent with most of the literature, chopped, dispersed items appeared to be the best, whereas presenting whole food items appeared to be the worst for welfare. In conclusion, presenting food in a distributed and chopped instead of whole manner is suggested to improve welfare of zoo-housed mangabeys.
... A study conducted at Paignton Zoo fed primates either chopped produce or whole produce or measured differences in feeding time for the group and individuals. Feeding time was significantly longer when fed whole vegetables Subordinate individuals also ingested a larger diversity of food items (Plowman et al. 2009). ...
Full-text available
It is common practice for keepers in zoological collections to provide animals in their care with food that is chopped into small pieces. Anecdotally, it has been suggested that chopped food reduces wastage and reduces aggression from group-housed animals. However, there is limited empirical evidence to support these suggestions. To investigate the effects of food condition (chopped or whole food), a study was undertaken on White-cheeked Turacos (Tauraco leucotis) and Fischer’s Turacos (Tauraco fischeri) at two zoological collections in the United Kingdom. This study investigated the effect of food condition on turaco behaviour, the amount of food eaten, and also the amount of time that keepers required to prepare the diet. There was no significant impact on the amount of food eaten as a result of providing whole food. For Fischer’s Turacos, the whole-food condition significantly increased the prevalence of feeding and foraging behaviour, whilst significantly reducing preening. For White-cheeked Turacos, only feeding and foraging was affected by food condition: no other behaviours were significantly affected by chopped or whole food. Keepers on average saved 151 s per meal when preparing whole-food diets. Overall, this study suggests that changing food presentation from chopped to whole has a limited impact on food intake and behaviour. Providing whole-food items may also save valuable keeper time. Future studies should investigate the impact of feeding whole-food items to a wider range of zoo-housed species.
The Malayan, or Asian, tapir (Tapirus indicus) has a diminishing wild population and is becoming more common in captivity as zoos attempt to manage sustainable ex situ populations. Tapirs can be relatively easy to maintain and breed, but captive animals appear to suffer from reduced activity budgets, obesity, and poor public image. A questionnaire-based survey was designed and sent specifically to 10 collections around the world that exhibit Malayan tapirs, with the aim of assessing husbandry regimes to determine prevalence of standardized practices as well as highlighting any key differences, and to showcase good practice, thus providing information beneficial to those maintaining this species in their zoo. Twenty-five animals were included in the survey from collections across four continents. The research's major conclusions show differing dietary make-up, with a lack of forage provision, contrasting with a diverse array of enrichment protocols used. Significant differences were noted between zoos for total amount of food offered (P = 0.000) as well as ratios of forage to concentrate pellet offered (P = 0.004). Comparing food offered to male and female tapirs with published requirements for an "average" of either gender shows not all zoos providing the amount suggested in husbandry guidelines. Intelligently designed and original enrichment was provided to all animals but differences between zoos were noted in the application and "usefulness" of enrichment for individual tapir. Overall, animals are benefiting from enrichment but welfare could be further improved via consistent feeding of ad libitum forage and regular use of browse as a constituent part of daily rations. Zoo Biol. 00:1-16, 2012. © 2012 Wiley Periodicals, Inc.
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