The Study On The Dynamic Emulation Model Of The Pig Breeding Farm Prodution System

By applying the principle, the theory and method of SD, Pig Production Science was integrated with Systems Engineering, Animal Systematic Management and Economy ect. Duroc breeding swine production system, Landrace breeding swine production system and Large Yorkshire breeding swine production system that were in the same dynamic emulation model were studied. On the basis of lots of investigation, pig breeding farm production system borderline and the relationship of interior herds were analysed and confirmed, the technical parameters biologic parameters and the economic parameters were accordingly confirmed, then Vensim4.0 that was special emulational language of SD was used to program, finally the dynamic emulation model of pig breeding farm production system was builded. By the analysis of emulational degree and emulational ability, model reliability was validated. The thesis mainly studied economy benefit, total inventories whose were Duroc breeding swine production system, Landrace breeding swine production system and Large Yorkshire breeding swine production system, structures of pig herds of three varieties, when pig breeding farm production system was steady, and the dynamic change ruler of breeding swine production system, when swine herds were changed suddenly, then conclutionswere as the follow:1.In accordance with actual circumstances of breeding swine production, swine herds consisted of sow , boar, replacement gilt, replacement boar, suckling piglet, weanling pig, growing pig, young pig, fattening pig. When pig breeding farm production system was steady, total inventories whose were Duroc breeding swine production system, Landrace breeding swine production system, Large Yorkshire breeding swine production system and the whole herds had all reference value.At the same time, structures of pig herds of three varieties could help governors to confirm total inventories of different scales.2. The percentage of sale Duroc growing pig, Landrace growing pig, Large Yorkshire growing pig and the percentage of sale Duroc young pig, Landrace young pig, Large Yorkshire young pig were given. By different market demands, adjusting two percentages, the model could give optimal percentages in order to provide references for governors to seek the most economy benefit.3. Such as Duroc breeding swine production system, when increasing replacement gilt largely, the dynamic change ruler of differet herds were emulated. The change of largely earlier was...