Alternative housing for sows and litters Part 5. Individual differences in the maternal behaviour of sows Anton D. Pitts a,* , Daniel M. Weary a , David Fraser a , Edmond A. Pajor c , Donald L. Kramer b a Animal Welfare Program, Faculty of Agricultural Sciences and Centre for Applied Ethics, University of British Columbia, 2357 Main Mall, Vancouver BC, Canada V6T 1Z4 b Department of Biology, McGill University, 1205 Docteur Pen®eld Avenue, Montre Âal, Que., Canada H3A 1B1 c Department of Animal Sciences, Purdue University, 1026 Poultry Science Building, West Lafayette, IN 47907-1026, USA Accepted 1 January 2002 Abstract `Sow-controlled' housing has been developed to address welfare and production concerns associated with close con®nement of the lactating sow and her litter, by permitting the sow to leavethelitteratwill.However,thereisariskthatvariationintheuseofthepiglet-free`get-away') area may lead to inadequate maternal care in some cases or to failure to bene®t from the system in others. To understand use of a get-away area more fully and to develop ways to predict or modify it, weanalysedalargedatasetn  96litters)derivedfromthreepreviousexperimentsandanewstudy on sow-controlled housing. Sows use of the get-away area was highly variable, and the variation increasedwithpigletagefrom1to4weeks.Relativeuseoftheget-awayareawasconsistentamong individualsowsoverthecourseoflactationandnegativelyrelatedtonursingfrequency.Sowstestedin two or more lactations showed no consistency from one lactation to another. Sows that used the get- awayareamore,especiallylateinlactation,tendedtobelighteratparturitionandtohavelargerlitters at birth and at weaning. Sow weight loss and average piglet weight gain tended to decrease as use of the get-away area increased and nursing frequency decreased. Five tests of maternal responsiveness to stimuli associated with piglet distress revealed consistent individual differences and a positive association between sensitivity to an isolated piglet and the amount of get-away use. We conclude thatuseoftheget-awayareaisanexpressioninpartofthesow'sinvestmentinheroffspring,andthat it is not necessarily indicative of low parental motivation. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Pigs; Housing; Parental care; Maternal style; Individual differences Applied Animal Behaviour Science 76 2002) 291±306 * Corresponding author.:Tel.: 1-604-822-5175; fax: 1-604-822-4400. E-mail address: apitts@interchange.ubc.ca A.D. Pitts). 0168-1591/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved. PII:S0168-159102)00012-6