SummaryTitle of the paper: Inbreeding depression for litter traits and the development of growth in the Göttinger Minipig A data set of 1191 litters from 282 sows and 6777 piglets weights from the Göttinger Minipig was analysed to estimate inbreeding depression for litter traits and the early growth rates up to an age of 12 month. The population ofthe Göttinger Minipig shows an average inbreeding of sows and piglets of about 10 % with a Standard deviation of 1.7 % with a nearly normal distribution of the inbreeding coefficients in contrast to most other studies about inbreeding depression. There is no inbreeding depression observed for number of piglets bom alive or bom dead within a litter, neither for inbreeding of sows nor for inbreeding of litters. For average and individual birth weights the inbreeding of sows show a significant influence while the inbreeding of the litter is not significant. With a 10 percent increase of the inbreeding of sows a reduction on individual birth weight of 70 gram is observed (70 % of the phenotypic Standard deviation). For the weight of piglets in the first 6 month both the inbreeding of sows and the inbreeding of litters show a significant effect. A 10 percent increase of inbreeding of sows or litters both leads to a reduction on weight within the first 6 month of 250 gram (20 % ofthe phenotypic Standard deviation.

SummaryTitle of the paper: Systematic crossbreeding as a tool to conserve endangered pig breeds Live conservation of purebred populations of old endangered pig breeds requires high financial subsidies because they are very inferior to actual commercial hybrids in overall economy. But subsidies may be considerably reduced if the endangered breeds can be integrated into regional crossbreeding schemes adapted to ecological production niches or designed for specific quality products. The aim of this study at the experimental station Relliehausen of Göttingen University was to compare the performance of two crossbred sows with the endangered breeds Saddleback (DS) and Bentheimer (BB) as dams sire (and LW/LR as dams dam) with commercial LW/LR-crossbred sows in their litter performance as well as meat production and quality traits of their progeny from the same PI(NN)-and (PI*HA)-terminal sires. 478 litters with 1,384 fattened and 1,037 carcass graded progeny of which about 600 underwent detailed carcass value and meat quality evaluations at a loin cross section and 48 with an additional sensoric test. Results show that in litter performance DS crossbred sows were comparable to LW/LR commercial sows but BB crossbred sows weaned 0.66 pigs less per litter. In FOM grading no significant differences were found between the three sow groups as well as between the two different terminal sires. This also applied for most meat quality traits but in intramuscular fat content unexpectedly the control pigs were the best and significantly superior to the BB-progeny. The typical highly significant quality differences due to the "Hampshire effect" were found between progeny of the (PI*HA)-boar as compared to PI-progeny. In a calculated overall economic value DS-progeny were 4 -5 DM and BB-progeny about 8 DM per pig inferior to the commercial controls. These differences are only 1/5 to 1/10 of the purebred inferiority of the endangered breeds. These results should be confirmed by a field trial under more extensive conditions (e.g. outdoor sow-and ecological fattener management).