Responses of farmed silver foxes (Vulpes vulpes) to excessive food availability: Implications for using food as a yardstick resource in motivation tests

a b s t r a c tRecent behavioural, cognitive and neurophysiological studies strongly suggest that fish are capable of psychological experiences. Therefore, identifying needs from the animals' point of view is likely to be one of the best approaches to understand their welfare. Motivational tests, as a measure of what animals want, have been developed and refined for some decades. Despite numerous studies on fish motivational systems, none have attempted to quantify their motivation using this approach. Motivation studies often imply operant tasks for which various devices are used. The aim of this study was to adapt a push-door to quantify motivation in a cichlid fish, the Mozambique tilapia (Oreochromis mossambicus). Males of this species have strong snouts which they use for a number of activities and are thus suited to push. Twelve males of different social status were tested for three kinds of reinforcers: food, social partner and a control (additional space with substrate only). The animals were required to work the door (push/touch) at an ascending cost in order to have access to the resources. Measures of motivation included latency to open the door, work attention and maximum price paid. Latency to open the door increased with increasing cost for all resources, with the highest latency for the control reinforcer. Work attention was constant with increasing costs for social partners and food, and higher than the control. Work attention decreased for the control as cost increased. Maximum price paid was consistent with these results, being higher for social partners and food than for the control. The results of the three measures were consistent with each other and showed that the push-door can be used to measure motivation in this species. Further refinement of the present experimental set up will allow the use of this paradigm in the future, in order to improve knowledge on how this species values and ranks its needs.

Section: Open Vs Closed Economy Training and Rewardsmentioning

confidence: 99%

Measuring motivation in a cichlid fish: An adaptation of the push-door paradigm

Galhardo

Almeida

Oliveira

2011

“…During the experiment, the intake of individual subjects was also monitored on a daily basis. If some food remained uneaten on 2 consecutive days, the ration was slightly reduced to avoid a possible loss of appetite and/or aversion to leftover food (Hovland et al, 2007). The food consisted of 50% protein, 33% fat and 17% carbohydrate with a metabolizable energy content of 115 kcal/100 g. Water was available from drinking cups in the operant cage and replenished three times a day.…”

Section: Operant Trial For Foodmentioning

confidence: 99%

Two's company? Solitary vixens’ motivations for seeking social contact

Hovland

Akre

Flø

et al. 2011

Self Cite

a b s t r a c tThe flexible social organisation in red foxes (Vulpes vulpes) suggests that social contact could enrich the housing of silver fox vixens (a selected line of red foxes) farmed for their fur. To investigate their social motivation, adult vixens housed in an operant apparatus were allowed to pull a loop for full physical contact with a same-aged vixen. The access cost was increased daily and their maximum price paid (MPP) measured. Five test and five stimulus animals were pair housed long-term in separate apparatuses over 5 weeks in November/December wherein each pair could have 12 h daily physical contact in a shared compartment. Prior to the operant trials, two food competition tests were completed to establish dominance relations within pairs. To examine vixens' motives for contact, social behaviour during interaction was also recorded. Subsequently, the test foxes' MPP for a comparator resource, food, was also measured and their relative price paid (RPP, %) for contact calculated. When access to the resource cage was free (FR1), at the start and end of the experiment, time spent in contact averaged approximately 1/6 (2 h) of the available time; this was stable between these periods. Neither visit rate to nor time spent in the shared compartment differed between the start and the end of the trial, indicating that the test subjects' social motivation remained stable during the experimental period. The MPP (mean ± SE) for social contact averaged at 560 ± 160.6 pulls; this was significantly lower (P = 0.015) than the MPP for food (2108 ± 526.6 pulls), representing a RPP of 24.8 ± 3.36%. During social interaction agonistic gaping signals occurred (though never serious fights requiring intervention), but there were also bouts of play, social exploration and high levels of synchronous resting. Aggressive behaviour during the second food test predicted the levels of aggression during operant trials. RPP positively correlated with the total time spent together (r = 0.87, P = 0.054), and with the time spent resting together (r = 0.89, P = 0.046). Differences in RPPs for contact and levels of agonism between pairs illustrate that social contact between adult vixens is enriching for some, but may put welfare at risk for others, especially if they have no opportunity to retreat from aggression. However, levels of agonistic behaviour during, e.g. food competition tests may be a possible indicator of the compatibility between potential cage mates. Due to the low number of animals the result must now be replicated with further animals.

“…During the experiment, the intake of individual subjects was also monitored on a daily basis. If some of the food remained uneaten on 2 consecutive days, the ration was slightly reduced to avoid a possible loss of appetite (Hovland et al, 2006b). The food was a standard wet paste for fur animals consisting of 50% protein, 33% fat and 17% carbohydrate with a metabolizable energy content of 115 kcal/ 100 g. Water was available from drinking cups in the operant cage and was replenished three times a day.…”

Section: Trial 2-motivation For Access To Foodmentioning

confidence: 99%

The nature and strength of social motivations in young farmed silver fox vixens (Vulpes vulpes)

Hovland

Mason

Kirkden

et al. 2008

Self Cite

To investigate the strength of social motivation and the motives underlying social contact in farmed silver foxes (Vulpes vulpes), we housed six young vixens continuously in a closed economy operant apparatus and measured their 'maximum price paid' when required to perform a task to obtain unrestricted social contact or food (a 'yardstick' resource). In the former trials, vixens of the same-age and origin acted as stimulus animals (N = 6), and both test and stimulus foxes could decide their own visit durations to a shared compartment. Their motives for visiting this 'social compartment' were examined by recording their behaviour during social contact. When access was almost free (a baseline fixed ratio schedule of 1) the test vixens visited the stimulus fox 30.3 AE 4.3 times and spent 45% of the time together per 24 h. The stimulus foxes spent on average 80% per 24 h in the shared compartment and visited this cage 40.7 AE 9.6 times per 24 h. When higher costs were imposed, the test vixens proved willing to pay to access the stimulus vixens and the average maximum price paid for contact was 38.3 AE 8.3% of the price paid for food when hungry. During the time spent together, the stimulus foxes made use of their opportunity to leave the cage, on average 1.43 AE 0.20 times per visit. The behaviour recordings showed that during initial encounters the vixens would fight to establish dominance, and in four of the pairs the test subject emerged as the dominant individual. However, during subsequent interactions, no serious aggression was recorded and social behaviour was characterised by higher levels of sniffing and grooming (23.7 AE 4.3 times/h), play signals (10.5 AE 4.1 times/h) and agonistic displays (5.5 AE 2.5 times/h). Not all of the time together was used for social interaction and during the observation period, the vixens allocated 33.1 AE 6.9% of the time to synchronous resting. We conclude that young silver fox vixens were motivated for social contact, and that this contact was beneficial for welfare due to the low level of aggression and the occurrence of grooming and play. #