Anticipation and frequency of feeding affect heart reactions in domestic pigs.

Measuring heart reactions has become a widely used method for the assessment of emotions. Heart rate and its variability, which can quite easily be noninvasively recorded, reflect the inputs of the sympathetic and parasympathetic branches of the autonomous nervous system. We tested the hypothesis that frequent anticipation of a positive event results in an increased state of welfare in pigs, expressed as positive arousal in anticipation of announced feeding as well as lowered heart rate and augmented heart rate variability during resting periods.

Individual calling to the feeding station can reduce agonistic interactions and lesions in group housed sows.

In this study we used a new call feeding station, which enabled sows to learn that they have access to feed only after an individual acoustic signal was given. We tested whether this call feeding station is able to reduce agonistic interactions between sows and whether effects of call feeding can further be improved by enrichment. A total of 85 gestating sows were kept in a dynamic group in a large waiting area (207 m²) equipped with littered laying areas and an outside area.

No apparent effect of an experimental narrow confinement on heart activity and cortisol in domestic pigs.

The effects of continuing spatial restraint were examined in domestic pigs. For this purpose, the animals (German Landrace barrows) were housed individually in metabolic cages (12 animals) and, as controls, in single pens (six animals). In six replications with two experimental animals and one control animal, we collected saliva each morning (0730 h) for the cortisol analysis, recorded the behaviour and the heart beat for 3 h/day (0800 to 0900 h, 1100 to 1200 h, 1400 to 1500 h).

Behavioural and cardiac responses towards conspecific distress calls in domestic pigs (Sus scrofa).

In domestic pigs, vocalisation can be an indicator of distress and negative emotional states. It might play a role in the transfer of emotion between individuals ('emotional contagion' or 'empathy'), which could result in impaired animal welfare on a group level based on the distress in an individual member of the group. The aim of this study was to characterise the responses of pigs to conspecific distress calls.

Learning to learn during visual discrimination in group housed dwarf goats (Capra hircus).

Using an automated learning device, we investigated "learning to learn" by dwarf goats (Capra hircus) in what was for them a familiar environment and normal social settings. Nine problems, each consisting of four discriminable black symbols, each with one S-super+ and three different S-super(-), were presented on a computer screen. Mean daily learning success improved over the course of the first four problems, and the improvement was maintained throughout the remaining five problems.