Effect of introducing piglets from farrow-to-finish breeding farms into all-in all-out fattening batches in Spain on productive parameters and economic profit J. Oliveira a,c, * , F.J. Guitia ´n b , E. Yus a a Patologı ´a Infecciosa y Epidemiologı ´a, Departamento de Patologı ´a Animal, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n. 27002, Lugo, Spain b Department of Veterinary Clinical Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, AL9 7TA, UK c Xesgavet S.L. (Xestio ´n Gandeira Veterinaria S.L.), Ru ´a Illa de Man, 4, 27002 Lugo, Spain Received 20 February 2005; received in revised form 10 February 2007; accepted 13 February 2007 Abstract A prospective study was conducted to assess the effect of introduction of piglets from farrow-to- finish farms on the global performance of all-in all-out fattening batches in Galicia (NW Spain). Two hundred and thirty-nine fattening batches from 48 fattening farms integrated in a cooperative were used in the study. All-in all-out fattening batches were classified according to the category of farm that supplied the piglets. Origin F was a fattening batch where all feeder piglets came from one or more farrow to feeder units versus origin FF, in case a group of piglets or all piglets of the batch came from farrow-to-finish farms. Productive parameters of fattening batches included in the study were recorded. Crude comparisons of performance of 37 fattening batches from origin F and 202 from origin FF were made. Mixed multiple linear regression models were used to assess the association between type of origin of feeder piglets and the following parameters: feed consumed per market hog, percentage of deaths (mortality) and time to slaughter. In all models, variables with presumable relationships with the outcomes were offered to the models as well as the biologically plausible interaction terms. www.elsevier.com/locate/prevetmed Preventive Veterinary Medicine 80 (2007) 243–256 * Corresponding author at: Patologı ´a Infecciosa y Epidemiologı ´a, Departamento de Patologı ´a Animal, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n. 27002, Lugo, Spain. Tel.: +34 619 784 124; fax: +34 982 252 195. E-mail address: jolivei@lugo.usc.es (J. Oliveira). 0167-5877/$ – see front matter # 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.prevetmed.2007.02.003