F. Hulten et al., PRE-WEANING AND POST-WEANING PIGLET PERFORMANCE, SOW FOOD-INTAKE AND CHANGE IN BACKFAT THICKNESS IN A GROUP-HOUSING SYSTEM FOR LACTATING SOWS, Acta veterinaria Scandinavica, 38(1), 1997, pp. 119-133
Four farms that group-housed sows from about 2 weeks of lactation unti
l weaning (G-farms) and 3 farms, used as controls, that kept the sows
individually penned throughout the 5 to 6-week-long lactation period (
C-farms) were compared in terms of pre- and post-weaning piglet growth
rate and mortality, sow food intake and change in backfat thickness.
Piglets from 169 G-farm sows and 136 C-farm sows were individually wei
ghed at the time of grouping and weaning. In addition, some of the pig
lets were weighed 2 weeks post weaning. Piglet mortality was recorded
during the pre- and post- weaning periods. Sow backfat thickness was m
easured at the time of grouping (at a corresponding time in the C-farm
s) and weaning, and sow food consumption was determined during the gro
up-housing period. Piglet weight, growth rate and within-litter variat
ion in growth rate did not differ significantly between the two groups
during the group-housing and postweaning periods. However, the pre- w
eaning growth rate varied considerably between farms. For multiparous
sows during the group-housing period, piglet mortality was higher (p =
0.002) in the G-farm group (6.5%) than in the C-farm group (1.4%). Ho
wever, for primiparous sows the corresponding piglet mortality was sim
ilar (p = 0.21) in the two groups. Significant between-batch variation
in mortality during the group-housing period was noted within the G-f
arms but not within the C-farms. At the time of weaning, backfat thick
ness tended (p = 0.09) to be higher in the G-farm group than in the C-
farm group. For primiparous sows the decrease in backfat thickness was
similar (p = 0.37) in the two groups. By contrast, multiparous G-farm
sows gained backfat during the group-housing period, whereas multipar
ous C-farm sows lost some backfat (p = 0.02). G-farm sows consumed 23%
more food than C-farm sows during the group-housing period. These res
ults indicate that productivity is lower in the group-housing system,
mainly owing to the poor performance of the older sows.