Are double bunks used by indoor wintering sheep?: Testing a proposal for organic farming in Norway

The frequency with which ewe lambs lay on wooden surfaces at two levels, called “double bunks,” was documented by video recording at 6, 11 and 18 months of age: the number in each of 4 pens (n = 4) lying either on double bunks (DBs) or on the expanded metal floor (EMF) was recorded. At 6 months, lambs were sheared half way through the research period and DBs of two different heights (50/60 cm) and depths (60/75 cm) were tested. At other ages the lambs were sheared before testing and all DBs were the 60 cm × 60 cm design.Fully fleeced lambs aged 6 months preferred to lie on EMF rather than DB (P < 0.001). After shearing, the use of EMF for resting declined (P < 0.05) and no significant preference between EMF and DB was found. The lambs tended to lie less when newly sheared (P = 0.06). At 11 months, sheared lambs used DB just as much as EMF, whereas 18 month old sheared ewe lambs tended to choose DB to lie on (P = 0.09). At 6 months, there was a tendency for more lambs to rest at ground level in the DB when headroom was higher at 60 cm (P = 0.1). No other preferences between DB designs were found.The results are discussed according to the regulations for organic sheep farming in Norway. The lambs showed little preference for resting on a DB compared to EMF, so there is insufficient evidence to recommend a two-level, wooden lying area for sheep.