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Eradication measures of a contagious animal disease may force farmers to keep ready-to-slaughter animals on the farm. As feeding heavy animals may reduce carcass quality and farmer income, farmers can adjust their feeding policy in order to decrease losses from delayed slaughter. The problem is interesting also from society's point of view because eradication measures can affect a large number of farms when a single farm is infected. A dynamic programming model is developed to study optimal hog feeding strategies when the timing of slaughter is restricted. The model takes into account carcass quality, its effects on timing of slaughter under given prices, and animal density on the farm. The results show that farmers suffer substantial losses due to delayed slaughter, and can minimize the losses by reducing energy feeding. The results give information on designing compensation schemes so that all farmers have economic incentives to implement preferred eradication policy.

Heritabilities and genetic correlations for different prolificacy traits were estimated to assess possibilities of selection for high number of piglets weaned. Three litter-size traits: total number of piglets born (TNB), number of piglets born alive (NBA), number of piglets weaned (NW); four piglet survival traits: number of stillborn piglets (NSB), percent of stillborn piglets (NSB%), piglet mortality between birth and weaning (PM), percent of dead piglets during suckling (PM%); and three traits measuring time intervals: age at first farrowing (AFF), first farrowing interval (FFI), and gestation length (GL) were analysed. The Finnish national litter recording scheme provided data on the first parity litters of 11 329 Landrace and 8 362 Large White pigs born between 1986 and 2000. The heritabilitiy estimates were moderate for AFF and GL (0.24–0.37), and low for all the other traits (0.03–0.11). The genetic correlations between TNB and PM (0.68 in Landrace and 0.43 in Large White) and between NBA and PM (...