PATTERNS OF CROSSFOSTERING AND PIGLET MORTALITY ON COMMERCIAL US AND CANADIAN SWINE FARMS

A data base of 300 farms using computerized records was used to examin e the extent and timing of crossfostering being practiced in commercia l herds in the Midwestern U.S. and Canada in 1994-1995. Crossfostering was used on 98% of farms. Across all farms, the mean percent of pigle ts crossfostered was 8.6%. Farms varied greatly in the age at which th ey moved piglets. The 20 farms that moved piglets the earliest after b irth were classified as early-move farms and the 20 that moved the old est piglets were classified as late-move farms. Early-move and late-mo ve farms did not differ in herd size (P = 0.14), average parity of far rowed sows (P = 0.47) or age at weaning (P = 0.37). There were differe nces between early-move and late-move farms in percent of piglets fost ered (P = 0.0001), pigs born alive/litter (P = 0.04), and pre-weaning mortality (P = 0.0005). A subset of late-move farms that were part of an integrated production group had unique production parameters that s uggested inaccurate record-keeping. (C) 1998 Elsevier Science B.V.