HOFMANN (1935) submitted a proposal, using a timed mating and farrowing system to program the reproductive dates in a sow herd and thus to direct the breeding and production cycle taut. In 1958 to 1964, the developed system of periodic farrowing was operated in Thuringia first farms successfully introduced. This work coincided with the beginning of the so-called "industrial methods of production" in the eastern livestock. First porcine semen collection centers emerged in 1961. From 1970, the proportion inseminated sows increased the total sow population from 10.6% to 86.6% in 1989. This made it possible to realize the nationwide uniform hybrid pig breeding program and the parallel developed reproductive technology in practice establish. Starting from an oriented on natural sexual cycle grouping of sows in the system of periodic farrowing other methods for cycle synchronization with young and old sows and birth control have been developed and filed either in the practice production cycles of sows producing farms in combination with AI. More than 85% of all sows were managed according to the principle of group farrowing system in East Germany across all farm size categories.