Abstract: From observations of intra-specific social grooming in cattle and studies on human stroking in other species, we hypothesised that cows' reactions to human stroking differ depending on the body regions being stroked. Moreover, we tested, whether cows `reactions to stroking change with the animals' experience of stroking. Sixty dairy cows were stroked in three different body regions, i.e. the withers, W, neck ventral, NV (both licked often in social grooming) and the lateral chest, LC (licked rarely), in a balanced order during 10-min sessions. Behavioural reactions and heart rate during stroking as well as reactions to the human just after stroking were recorded. Two test sessions were carried out with 3 weeks of treatment in-between. During this period, the cows were randomly allocated to four treatment groups: three groups received 5 min of daily stroking in either W, NV or LC and the last one (control group) was exposed to simple human presence. During stroking W and NV, cows showed longer neck stretching and ear hanging than during stroking LC (P < 0.001). Moreover, ear hanging was shown longer when W was stroked as compared to NV (P < 0.001), but neck stretching was observed longer during stroking NV as compared to W only after the treatment period (P < 0.01). In the first test session, more animals showed head shaking and head throwing during stroking W and NV than LC (P < 0.01), whereas in the second test session these behaviours were observed only in few animals. In the first test session heart rate was higher during stroking W than the other body regions (P <= 0.01). In the second test session, the lowest heart rate was found during stroking NV (P < 0.05). Finally, contact with the experimenter following stroking differed for the three body regions stroked in both test sessions (first: P = 0.06, second: P < 0.01); contact was shortest for LC. When comparing both test sessions, stretching the neck and ear hanging increased (P < 0.001), while head shaking and head throwing decreased (P < 0.05); there was no difference for heart rate and contact with the experimenter. The four treatments had no influence on reactions to stroking. To conclude, stroking of body regions often licked during social grooming led to more responses than stroking the one licked rarely. Some reactions, such as stretching the neck, are also observed during social licking. This suggests that cows may in part perceive human stroking of body regions often licked similarly to social licking. This knowledge could be of interest for an improvement in quality of human-cattle interactions.

Abstract: Venezuelan encephalitis (VE) virus has intermittently produced epidemics and equine epizootics on the dry Pacific coastal plain of Peru since at least the 1930's. However, evidence that the virus exists in the Amazon region of Peru to the east of the Andes mountains was not obtained until antibodies were found in human sera collected in 1965, and 10 strains of the virus were isolated in a forest near the city of Iquitos, Peru during February and March 1971. Eight strains came from mosquitoes and two from dead sentinel hamsters. Three hamsters exposed in forests near Iquitos developed VE virus antibodies suggesting that hamster-benign strains also exist there. Antibody tests of equine sera revealed no evidence that VE virus was actively cycling during the late 1950's or 1960's in southern coastal Peru, where equine epizootics had occurred in the 1930's and 1940's. In northern coastal Peru bordering Ecuador, antibodies were present in equine sera, presumably residual from the 1969 outbreak caused by subtype I virus, since neutralizing antibody titers were higher to subtype I virus than to subtypes III or IV. No VE virus was detected in this northern region during the dry season of 1970 by use of sentinel hamsters. The possibility is considered that VE epidemics and equine epizootics on the Pacific coast of Peru are caused by movements of virus in infected vertebrates traversing Andean passes or in infected vertebrates or mosquitoes carried in airplanes from the Amazon region.

Abstract: The assessment of cognitive functions in rodents represents a critical experimental variable in many research fields, ranging from the basic cognitive neurosciences to psychopharmacology and neurotoxicology. The increasing use of animal behavioral tests as 'assays' for the assessment of effects on learning and memory has resulted in a considerable heterogeneity of data, particularly in the field of behavioral and psycho pharmacology. The limited predictive validity of changes in behavioral performance observed in standard animal tests of learning and memory indicates that a renewed effort to scrutinize the validity of these tests is warranted. In humans, levels of processing (effortful vs. automatic) and categories of information (procedural vs. episodic/declarative) are important variables of cognitive operations. The design of tasks that assess the recall of 'episodic' or 'declarative' information appears to represent a particular challenge for research using laboratory rodents. For example, the hypothesis that changes in inspection time for a previously encountered place or object are based on the recall of declarative/episodic information requires substantiation. In order to generalize findings on the effects of neuronal or pharmacological manipulations on learning and memory, obtained from one species and one task, to other species and other tasks, the mediating role of important sets of variables which influence learning and memory (e.g. attentional, affective) needs to be determined. Similar to the view that a neuronal manipulation (e.g. a lesion) represents a theory of the condition modeled (e.g. a degenerative disorder), an animal behavioral task represents a theory of the behavioral/cognitive process of interest. Therefore, the test of hypotheses regarding the validity of procedures used to assess cognitive functions in animals is an inherent part of the research process.

Abstract: A central question in the interspecific human/animal relationship is how domestic animals perceive humans as a significant element of their environment. In this study, we tested the hypothesis that the use of positive or negative reinforcement in horse training may have consequences on the animals’ perception of humans, as a positive, negative or neutral element. Two groups of ponies were trained to walk backwards in response to a vocal order using either positive or negative reinforcement. Heart rate monitors and behavioural observations were used to assess the animals’ perception of humans on the short (just after training) and long (5 months later) terms. The results showed that the type of reinforcement had a major effect on the subsequent animals’ perception of familiar and unfamiliar humans. Negative reinforcement was rapidly associated with an increased emotional state, as revealed by heart rate measurements and behavioural observations (head movements and ears laid back position). Its use led the ponies to seek less contact with humans. On the contrary, ponies trained with positive reinforcement showed an increased interest in humans and sought contact after training. This is especially remarkable as it was reached in a maximum of 5 sessions of 1 to 3 min (i.e. 5 to 15 min) and had lasting effects (visible after 5 months). Even learning was positively influenced by positive reinforcement. Overall, horses seem capable of associating humans to particular experiences and display extended long-term memory abilities.