Environment The sow requires an extra 6 MJ DE/day (or about 0.45 kg/d) for each 5ºC below the lower critical temperature
Housing The sow kept in individual stalls may require an extra 2.5 MJ DE/day (or about 0.2 kg/d) because their activity is greater and, consequently, their energy requirement for maintenance is greater than that for group housed sows. In addition, the individually housed sow usually has a higher Lower Critical Temperature than sows kept in groups.
Health If the disease burden in the herd is high, pregnant sows may require up to 0.5 kg feed/day to cover the extra energy requirements for maintenance
Feed intake in pregnancy Feed levels need to be adjusted depending upon temperature, housing, sow size, health status. Protein levels are usually adequate with minimum of 13% crude protein and 0.5% lysine. No simple recipe for determining feed level for sows during pregnancy.