Skiljer sig hundvalpars lekbeteende åt mellan raser och kön?

Abstract: There are many theories why animals play but none have jet been proven. During observation on Canids, play seems to be important when they learn to control the intensity of the bite and to facilitate the social structure within a group. When dogs play they perform behaviours that otherwise are used during hunting, reproduction and aggression that in another context would be for example hostile. The dog is one of the species that we humans have domesticated and they have been exposed to an intense and concentrated breeding so they can function in different areas, for example herding and hunting. This breeding has resulted in that the pure bred dogs can be very different between the breeds. In several studies there have been differences between breeds among adult dogs when it comes to play behaviour but no studies have been done regarding puppies. The aim of this study was to see if there were any difference in the way puppies play between the breeds Germen shepherd, Border collie and Labrador retriever. An additional aim was to see if there are any difference between the genders regarding witch gender they prefer to play with and if they genders play in different ways. To test significant differences Kruskal-Wallis test were used. 48 puppies of the breeds Border collie, Labrador retriever and Germen shepherd took part in the study. Four litters from each breed and four individuals (two females and two males) from each litter were observed during two occasions during one day, a total of 16 minutes per puppy. Each puppy was observed during one minute and all play behaviours were registered and then next puppy was observed and so on. The observations were performed were the puppies lived and they were either outside or inside during the study. The puppies were 43-55 days old when they were observed. The study showed that there were significant differences between the breeds in four play behaviours; jump on top of another puppy (p<0,05), runplay (p<0,01), shake a toy (p<0,05) and stand over another puppy (p<0,05). The fact that there were differences between the breeds may depend on that they have been breed to different purposes and that these behaviours are shown when they are puppies. There were no difference between the sexes, and this may be because the puppies have not yet reached sexual maturity and therefore have not yet developed behaviour differences detected in adult dogs. It appeared that the females played more with the males than other females, but to explain this it requires further studies