Mother goats do not forget their kids' calls.

Parent-offspring recognition is crucial for offspring survival. At long distances, this recognition is mainly based on vocalizations. Because of maturation-related changes to the structure of vocalizations, parents have to learn successive call versions produced by their offspring throughout ontogeny in order to maintain recognition. However, because of the difficulties involved in following the same individuals over years, it is not clear how long this vocal memory persists. Here, we investigated long-term vocal recognition in goats. We tested responses of mothers to their kids' calls 7-13 months after weaning. We then compared mothers' responses to calls of their previous kids with their responses to the same calls at five weeks postpartum. Subjects tended to respond more to their own kids at five weeks postpartum than 11-17 months later, but displayed stronger responses to their previous kids than to familiar kids from other females. Acoustic analyses showed that it is unlikely that mothers were responding to their previous kids simply because they confounded them with the new kids they were currently nursing. Therefore, our results provide evidence for strong, long-term vocal memory capacity in goats. The persistence of offspring vocal recognition beyond weaning could have important roles in kin social relationships and inbreeding avoidance.

Classification of pig calls produced from birth to slaughter according to their emotional valence and context of production.

Vocal expression of emotions has been observed across species and could provide a non-invasive and reliable means to assess animal emotions. We investigated if pig vocal indicators of emotions revealed in previous studies are valid across call types and contexts, and could potentially be used to develop an automated emotion monitoring tool. We performed an analysis of an extensive and unique dataset of low (LF) and high frequency (HF) calls emitted by pigs across numerous commercial contexts from birth to slaughter (7414 calls from 411 pigs). Our results revealed that the valence attributed to the contexts of production (positive versus negative) affected all investigated parameters in both LF and HF. Similarly, the context category affected all parameters. We then tested two different automated methods for call classification; a neural network revealed much higher classification accuracy compared to a permuted discriminant function analysis (pDFA), both for the valence (neural network: 91.5%; pDFA analysis weighted average across LF and HF (cross-classified): 61.7% with a chance level at 50.5%) and context (neural network: 81.5%; pDFA analysis weighted average across LF and HF (cross-classified): 19.4% with a chance level at 14.3%). These results suggest that an automated recognition system can be developed to monitor pig welfare on-farm.

Looking on the Bright Side of Livestock Emotions-the Potential of Their Transmission to Promote Positive Welfare.

Emotions can be defined as an individual's affective reaction to an external and/or internal event that, in turn, generates a simultaneous cascade of behavioral, physiological, and cognitive changes. Those changes that can be perceived by conspecifics have the potential to also affect other's emotional states, a process labeled as "emotional contagion." Especially in the case of gregarious species, such as livestock, emotional contagion can have an impact on the whole group by, for instance, improving group coordination and strengthening social bonds. We noticed that the current trend of research on emotions in livestock, i.e., investigating affective states as a tool to assess and improve animal welfare, appears to be unbalanced. A majority of studies focuses on the individual rather than the social component of emotions. In this paper, we highlight current limitations in the latter line of research and suggest a stronger emphasis on the mechanisms of how emotions in livestock are transmitted and shared, which could serve as a promising tool to synergistically enhance the welfare of all individuals within a group.

Effect of acetaldehyde on behavioral and neurochemical changes induced by MK-801 in rats.

Alterations in motor activity related to dopamine changes in some brain regions have been described as consequences of the modifications produced by systemic administration of MK-801 (a noncompetitive NMDA receptor antagonist) in rats. Acetaldehyde (ACH), the main metabolite of ethanol, has been implicated in different alterations in the central nervous system after ethanol ingestion. ACH might exert some control on dopaminergic transmission through the formation of other compounds with dopamine, which eventually may modify dopamine content and its metabolism. In order to evaluate such a hypothesis, we used Wistar rats in the present study to evaluate the effect of ACH on locomotor alterations and dopamine metabolism changes induced by MK-801. Our results show that the MK-801-treated group had a significant increase in locomotor activity. In contrast, we did not find significant differences in locomotion tests after ACH administration. However, the group to which both drugs were administered showed a significant decrease in locomotor activity compared with those given MK-801 alone. Neurochemical analysis showed an increase in dopamine content in the striatum and frontal cortex after MK-801 administration, however; the increase was reversed by giving 200 mg/kg of ACH. These results indicate that ACH can produce an antagonic-like effect on locomotor alterations and dopamine content changes induced by MK-801, thus modulating the MK-801-induced hyperlocomotion by interfering with dopamine metabolism.