Preference and possible consumption of provided enrichment and bedding materials and disinfectant powder by growing pigs

Background Domestic pigs have an evolutionary conserved exploratory behaviour. To comply with this requirement, the European Union aims at setting standards for appropriate enrichment materials for pigs (Council Directive 2008/120/EC). As recommended characteristics include ‘chewable’ and ‘edible’, pigs might also consume these materials (Commission Recommendation (EU) 2016/336), which are often additionally advertised to enhance lying comfort and hygienic conditions in stables. To date, a wide range of bedding, enrichment and disinfectant materials is available on the market to ensure environmental enrichment, a dry, hygienic environment or lying comfort. Previous studies revealed considerable amounts of undesirable substances in some of these materials possibly being a risk for food safety considering oral uptake by the animal. To determine interest and indicators for consumption of different types of materials by pigs during exploratory behaviour, a camera-assisted observational study with 12 female pigs (German Landrace) was conducted. We tested their preference for a disinfectant powder, peat, biochar and straw as reference material in a 4 × 6 factorial arrangement. Results Pigs manipulated and consumed all offered materials. However, longest manipulation time per pig was observed for biochar (63 min/day) and peat (50 min/day) (p < 0.05). Analyses of the bulk molecular-chemical composition and n-alkanes and acid insoluble ash as markers in the materials and in faeces clearly revealed the consumption of these materials by pigs. Conclusions Whether the consumption of considerable amounts together with certain levels of undesirable substances represents a risk for pig and consumer health could yet not be established. Future studies will address the quantitative contribution of undesirable substances by oral ingestion of bedding and enrichment materials and disinfectant powders to the daily feed ration.

Neuromodulatory Mechanisms оf a Memory Loss Preventive Effect of Alpha-Lipoic Acid in an Experimental Rat Model of Dementia

This study evaluates some of the neuromodulatory mechanisms of the memory loss preventive effect of alpha-lipoic acid (ALA) in a scopolamine (Sco)-induced rat model of an Alzheimer’s disease (AD) type dementia. Our results confirmed that Sco administration induces significant memory impairment, worsens exploratory behaviour and habituation; it increases acetylcholinesterase (AChE) activity and induces pathological monoamine content changes in the brain prefrontal cortex and hippocampus. ALA administration prevented to a large extent Sco-induced memory impairment; it also improved exploratory behaviour and preserved habituation; it decreased AChE activity, reversing it to Control group levels and corrected aberrant monoamine levels in the brain prefrontal cortex and hippocampus. According to the data available, this is the first time that ALA-induced changes in AChE and monoamine levels in the brain prefrontal cortex and hippocampus (brain structures related to learning and memory) have been demonstrated in a Sco-induced rat model of AD type dementia.

Decreased Phase–Amplitude Coupling Between the mPFC and BLA During Exploratory Behaviour in Chronic Unpredictable Mild Stress-Induced Depression Model of Rats

Depression is a common neuropsychiatric illness observed worldwide, and reduced interest in exploration is one of its symptoms. The control of dysregulated medial prefrontal cortex (mPFC) over the basolateral amygdala (BLA) is related to depression. However, the oscillation interaction in the mPFC-BLA circuit has remained elusive. Therefore, this study used phase–amplitude coupling (PAC), which provides complicated forms of information transmission by the phase of low-frequency rhythm, modulating the amplitude of high-frequency rhythm, and has a potential application for the treatment of neurological disease. The chronic unpredictable mild stress (CUMS) was used to prepare the rat models of depression. Moreover, multichannel in vivo recording was applied to obtain the local field potentials (LFPs) of the mPFC, the BLA in rats in control, and CUMS groups, while they explored the open field. The results showed prominent coupling between the phase of theta oscillation (4–12 Hz) in the mPFC and the amplitude of high-gamma oscillation (70–120 Hz) in the BLA. Compared to the control group, this theta–gamma PAC was significantly decreased in the CUMS group, which was accompanied by the diminished exploratory behaviour. The results indicate that the coupling between the phase of theta in the mPFC and the amplitude of gamma in the BLA is involved in exploratory behaviour, and this decreased coupling may inhibit exploratory behaviour of rats exposed to CUMS.

Sex-specific covariance between metabolic rate, behaviour and morphology in the ground beetle Carabus hortensis

Background Individuals within the same species often differ in their metabolic rates, which may covary with behavioural traits (such as exploration), that are consistent across time and/or contexts, and morphological traits. Yet, despite the frequent occurrence of sexual dimorphisms in morphology and behaviour, few studies have assessed whether and how sexes differ in metabolic trait covariances. Methods We investigated sex-specific relationships among resting or active metabolic rate (RMR and AMR, respectively) with exploratory behaviour, measured independently of metabolic rate in a novel environment, body size and body mass, in Carabus hortensis ground beetles. Results RMR, AMR and exploratory behaviour were repeatable among individuals across time, except for male RMR which was unrepeatable. Female RMR neither correlated with exploratory behaviour nor body size/body mass. In contrast, AMR was correlated with both body size and exploratory behaviour. Males with larger body sizes had higher AMR, whereas females with larger body sizes had lower AMR. Both male and female AMR were significantly related to exploratory behaviour, though the relationships between AMR and exploration were body mass-dependent in males and temperature-dependent in females. Discussion Differences between sexes exist in the covariances between metabolic rate, body size and exploratory behaviour. This suggests that selection acts differently on males and females to produce these trait covariances with potentially important consequences for individual fitness.

Inter-individual differences of calling and exploratory behaviour in a lebinthine cricket species hint at different mate-finding strategies

Individual fitness can be boosted by behavioural strategies that maximise mate-finding probability while minimising predation risk. Animals that use acoustics to find mates may benefit from using both stationary calling and active exploration, but these also expose them to different types of predators. Studying calling and searching behaviours concurrently allows us to understand their evolutionary trade-offs between survival and reproduction. Unlike most other crickets, lebinthine males alternate between singing and exploration to find females, which offer a unique and excellent opportunity to test for inter-individual differences and behavioural syndrome between call properties and exploratory behaviours. Our data demonstrate that call properties and exploratory behaviour were repeatable. We did not, however, find that call properties correlate with exploration as some consistently exploratory individuals produce longer calls while others produce shorter calls. Our study suggests that lebinthine males use different combinations of calling and exploratory behaviours to cope with unpredictable risk–benefit scenarios.

Autonomously Learning About Meaningful Actions from Exploratory Behaviour

<p>The thesis addresses the problem of creating an autonomous agent that is able to learn about and use meaningful hand motor actions in a simulated world with realistic physics, in a similar way to human infants learning to control their hand. A recent thesis by Mugan presented one approach to this problem using qualitative representations, but suffered from several important limitations. This thesis presents an alternative design that breaks the learning problem down into several distinct learning tasks. It presents a new method for learning rules about actions based on the Apriori algorithm. It also presents a planner inspired by infants that can use these rules to solve a range of tasks. Experiments showed that the agent was able to learn meaningful rules and was then able to successfully use them to achieve a range of simple planning tasks.</p>

Autonomously Learning About Meaningful Actions from Exploratory Behaviour

<p>The thesis addresses the problem of creating an autonomous agent that is able to learn about and use meaningful hand motor actions in a simulated world with realistic physics, in a similar way to human infants learning to control their hand. A recent thesis by Mugan presented one approach to this problem using qualitative representations, but suffered from several important limitations. This thesis presents an alternative design that breaks the learning problem down into several distinct learning tasks. It presents a new method for learning rules about actions based on the Apriori algorithm. It also presents a planner inspired by infants that can use these rules to solve a range of tasks. Experiments showed that the agent was able to learn meaningful rules and was then able to successfully use them to achieve a range of simple planning tasks.</p>

Deliberate practice

A large volume of research has shown that acquiring expertise in any domain is heavily influenced by the amount of deliberate practice (DP) the performer engages in over time. This chapter provides an overview of Ericsson’s highly influential theory of deliberate practice (DP) and argues that DP is essential if performers are to maintain and improve their skill levels over time. One of the primary goals is to distinguish between mechanical practice and DP. In doing so, the chapter posits that mechanical practice involves mindless repetition of well-learned skills while DP involves the use of reflective and self-regulatory processes to identify and correct errors (movement patterns that produce undesirable motor outputs) and to inspire exploratory behaviour. The chapter also argues that DP activities are often characterized by experimentation, playfulness, and enjoyment and that these are important components of expertise because they increase one’s motivation or desire to stick with difficult tasks.

Alternate without alternative: neither preference nor learning explains behaviour of C57BL/6J mice in the T-maze

In rodents, the T-maze is commonly used to investigate spontaneous alternating behaviour, but it can also be used to investigate preference between goods. However, for T-maze preference tests with mice there is no recommended protocol and researchers frequently report reproduction difficulties. Here, we tried to develop an efficient protocol with female C57BL/6J CrL mice for preference tests. We used two different designs, adapting habituation, cues and trial timing. However, in both experiments mice did not show any preference, although we used goods which we knew mice find rewarding. Instead, they alternated choices indicating that exploratory behaviour overruled preference. We argue that this behavioural strategy has evolved as an adaptive trait in saturated conditions where there is no need to take the reward immediately. Therefore, we deem the T-maze unsuitable for preference testing with the procedures we used here.

The Open Field Test

The Open Field Test (OFT) is the most widely used method for observing the behaviour of mice and rats 18 under laboratory conditions. It is used to evaluate the exploratory behaviour, general locomotor activity 19 and emotionality of rats and mice. However, it has to be kept in mind that these behaviours are not 20 independent, they interact and so a change in one will affect another. Despite being a seemingly simple 21 test, several caveats need to be acknowledged when selecting the variables for analysis and interpreting 22 the data with regard to the aforementioned domains. The observed behaviours can depend on a number of 23 procedural, environmental and biological factors, which should be carefully considered when planning the 24 experiment, as well as during the analysis and interpretation of the results. This review provides a critical 25 overview of these factors, followed by some warnings and practical tips for conducting the OFT.