INFLUENCE OF GENE-MARKERS ON BREEDING, FA TTENING AND CARCASS PERFORMANCE TRAITS OF A HOMOZYGOUS STRESS-RESISTANT GERMAN-LANDRACE SOW HERD

With the aim of the halothane reaction and the haplotyping of the link age-group (S-Hal-Gpi-H-Po2-Pgd) of the bloodgroup-, enzyme- and serump roteinsystems S, H, Gpi, Po2 and Pgd a homozygous-stressresistant Germ an-Landrace sow-herd could be established. The 47 reproductive sows we re selected in two groups (group 1 = 28 resting sows and group 2 = 19 culled sows) and attached to their 60 performance tested descendants t o increase the breeding-, fattening- and carcass performance traits. T he performance tested animals of the genotype Hal (NN) had significant ly better results in pH-values and meat-brightness compared with the N n-animals. A clear relationsship could be detected only for the traits ''food-conversion-rate'' and ''pH1-value in the loin'' with the genot ypes of the S-system. Haplotypes could be used only with restrictions for the selection of performance traits, but clearly for the eleminati on of the Hal (n)-allel. The LPA-decendants of the group 1 had a signi ficantly better daily weight gain and a shorter fattening period with a lower food-conversion rate compared with the group 2. The breeding p erformance traits ''piglets born living'', ''raised piglets'' and ''lo st piglets until day 28'' were significantly better in the first group . A comparison of the genotypes showed only for the H (-/-)-type signi ficantly better results. The selection by haplotypes of the breeding p erformance is not practicable, due to the poor relationsships with onl y one significant difference in the trait ''piglet losses''. In a homo zygous-stressresistant German-Landrace sow-herd it is possible to enha nce the breeding-, fattening- and carcass performance traits up to the level of a comparable heterozygous herd-book farm by performance sele ction.