Breed differences in behavioural response to challenging situations in kittens.

In a previous experiment, the behaviour of Oriental/Siamese/Abyssinian (OSA) kittens was compared with that of Norwegian Forest kittens (NFO) in a repeated Open Field Test (OFT), and significant differences emerged. To further investigate such variations, we analyzed kittens' responses to a potentially threatening object (TO) during the OFT. It was a metal spring enveloped in a cotton case suddenly bouncing out of the cylinder after the first 6 min of OFT exposure, and the test lasted 6 more minutes. From the 4th to the 10th week of age, during each test, the response of 43 OSA kittens and 39 NFO kittens to the TO was analyzed. Heart rate (HR) before and after the test was recorded. Behaviours were recorded and analyzed by focal animal sampling. Behavioural modifications recorded after TO exposure confirmed our suggestions on slow limbic system development in NFO kittens, as previously suggested by poor habituation and poor memory retention of repeated OFT exposure. The evident avoiding response to the TO confirmed the adoption in NFO kittens of an active-coping strategy towards challenge, as indicated also by their high scores for exploration and escape attempts. Otherwise, poor TO influence on exploration observed in OSA kittens suggested the adoption of a passive coping strategy, as previously shown by low levels of exploration and intra-session reduction in the number of vocalizations. Nevertheless, some of the behaviours observed, and the evidence of emotional tachycardia in OSA kittens, suggested also that the low level of activity recorded could have been due to a low arousability predisposition in this breed. The perception of a poorly arousing potential in the experimental setting might have influenced the perception of danger and the behaviour adopted in OSA kittens.

Breed differences in behavioural development in kittens.

Differences in behaviour of pure breed cats have been suggested but not wholly investigated. Oriental/Siamese/Abyssinian (OSA) kittens (n=43) were weekly compared with Norwegian Forest (NFO) kittens (n=39) from the 4th to the 10th week of age in a repeated Open Field Test (OFT) paradigm. Heart rate (HR) and rectal temperature (RT) before and after the test, and behavioural responses during the OFT were recorded. Behaviours registered were analysed by focal animal sampling. Significant breed differences were found; cats of the northern zones (NFO) seem to develop earlier thermoregulatory abilities. Precocious opening of eyes, higher locomotion scores and longer time spent standing, observed in OSA kittens may indicate an earlier neurological development. Inter breed differences recorded for exploration and locomotion seem to indicate coping style divergences: in the OFT challenging situation OSA kittens presented higher emotional tachycardia and performed more passively, with a faster decline in exploration and locomotion scores. NFO kittens exerted a more active behaviour as they spent more time exploring the arena and in escape attempts. Notwithstanding OSA and NFO cat selection was mainly aimed to improve divergent morphological traits, some different behavioural and physiological traits seem to have been maintained or co-selected within each breed.

Development of a polymerase chain reaction-based in vivo method in the diagnosis of subclinical pigeon circovirus infection.

This paper describes a polymerase chain reaction (PCR)-based method performed on blood samples and intestinal content to detect subclinical pigeon circovirus (PiCV) infection in live pigeons. In addition, two sets of primers (primer set 1 and 2), designed in two different regions of the viral genome, were used to provide evidence of possible differences in PCR responses. Blood and intestinal content samples were randomly collected from a total of 50 apparently healthy meat pigeons, aged 1 to 5 wk, which came from central Italy. Samples of primary lymphoid organs were also collected. Results showed a high level of PiCV infection, although clinical signs were not present. The results obtained with the two sets of primers showed that primer set 2 was able to detect a higher number of PCR-positive pigeons (45 of 50 pigeons) than primer set 1 (11 of 50 pigeons). In both cases an increase in positive results with pigeon age indicates that the major direction of transmission is likely horizontal. In these circumstances feces can play an important epidemiologic role, as supported by the consistent circovirus detection in intestinal content. The high sensitivity of this PCR test, which is able to detect very low amounts of viral DNA (5.5 x 10(-3) fg of plasmid containing the cloned PiCV genome), makes it suitable for possible application as an epidemiologic tool for identifying virus carriers for subsequent removal from lofts.