Replication data for: The standardized ileal digestible lysine-to-net energy ratio in the diets of lactating primiparous sows to optimize maternal nitrogen retention is dynamic but does not impact piglet performance

The optimal standardized ileal digestible lysine-to-net energy ratio is dynamic during lactation for primiparous sows. This dataset describes the optimal ratios in each week of lactation for maximizing maternal nitrogen retention. The ratio did not influence milk nitrogen output or piglet growth.