[Postpartum N-balance in lactating sows]

Continuous N-balances with sows (13 first litters and 118 piglets) were performed over 14 days. Milk yield was calculated using the daily gain of the suckling piglets. The amount of feed before farrowing was varied, during the trials feeding was ad libitum. In both trials reductions of milk yield were observed after 1 weak of lactation. The animals with the highest energy intake a. p. showed best performances in suckling time. There were 65 treatments with antibiotics caused by rectal temperatures of sows above 39.5 degrees C. High feeding of sows a. p. in accordance to the need is recommended with restricted and increasing amounts during the first week of lactation. Peripartal additives such as antibiotics or acids can be useful for health and performances.