[Ethologic determinants of maternal behavior in swine].
Care giving behaviour was investigated in pigs as a form of maternal behaviour and its effects on the youngs. The objective of observation was to compare the identified phenomena in their biological, social and experience variables of the behaviour of the investigated animals. The observations included 40 sows and 280 youngs of the Landrace x Large White breed, of the female sex. They took place in semi-natural conditions while the standard criteria of management were maintained. Two categories of sows and their youngs were investigated. The first group included 20 sows (first-litter gilts) and their youngs: A (1-20). A study unit comprised one sow and seven youngs. The other category, B (1-20), had analogical numbers of individuals but the sows were after their third parturitions. As an indicator of maternal behaviour the average index of sociability (IS) had the value mean = 1.7 for the first category and the value mean = 2.0 for the second category. Evaluation of these differences enables to determine a significant difference between the average IS for both groups (Fig. 1). This fact, which spoke in favour of B (1-20) group, made us follow the different litters. That means we wanted to know how the maternal behaviour determined piglet sociogenesis. IS was calculated from the average values of IS determined in both categories within their adequate litters. The value mean A (a-g) = 1.8 was determined for the first category (Tab. II) while for the second category B (1-20) the value mean B (a-g) made 2.0 (Tab. III).(ABSTRACT TRUNCATED AT 250 WORDS)