The performance of group-housed sows offered a high fibre diet ad libitum

As a part of a study investigating the extent to which ad libitum feeding o f a high fibre diet could mitigate behavioural problems associated with foo d restriction, the performance of sows given food at restricted or ad libit um levels was compared. Ten subgroups of five were allocated to each of the restricted (R) and ad libitum (A) feeding regimes. Five weeks after servic e, subgroups were introduced into one of two dynamic groups of sows housed in adjacent straw-bedded pens. R sows received a fixed daily ration (parity 1: 2.2 kg; parity 2: 2.4 kg) of a conventional pregnancy diet (13.1 MJ dig estible energy per kg)from an electronic sow feeder. Sows on the A regime h ad unrestricted access to five single-space hoppers dispensing a high fibre diet (containing 600 g unmolassed sugar beet pulp per kg). Subgroups were maintained on these gestation feeding regimes for two consecutive parities. During both parities, A sows were heavier by day 50 of gestation (parity 1 : P < 0.05; parity 2: P < 0.01) and at farrowing (parity 1: P < 0.001; pari ty 2: P < 0.001) than R sows. No difference was found between feeding regim e in sow weight at weaning, due to a greater weight loss during lactation o f A (parity 1: P < 0.001; parity 2: P < 0.001) than R sows. No difference w as found between feeding regime in sow backfat thickness, sow reproductive performance or litter performance in either parity. This suggests that unmo lassed sugar beet pulp diets may be used to feed sows on an ad libitum basi s during gestation without compromising productivity. However, food intakes may be too high (estimated at 4.1 kg per sow per day) to make ad libitum f eeding of pregnant sows an attractive option for producers.