FATTENING AND CARCASS PERFORMANCE TRAITS OF GERMAN LANDRACE CASTRATESGENETICALLY DIFFERENTIATED BY THE MHS-GENE-TEST

With the aid of the MHS-gene-test the genotypes of the disposition for the development of the malignant hyperthermie-syndrome was determined in 229 male DL-castrates of the progeny testing on the test stations Grub and Schwarzenau. Between the three possible MHS-genotypes NN (pur e stress-resistant), NP (mixed stress-resistant) and PP (pure stress-s usceptible) the former two showed lesser differences of the performanc e traits than to the latter. Concerning the NN-animals the following d ifferences could be verified in comparison to the NP- and PP-castrates : 1. a lower daily gain (26-34 gr) 2. higher fat-thickness measurement s (0.1-0.5 cm) with a increased fat surface (0.9-2.5 cm2) 3. a reducti on in thickness (0.2-0.6 cm) and surface (1.5-5.6 cm2) of the loin 4. a lower lean meat (0.8-2.7%) and ham yield (0.7-1.0%) 5. a lower quali ty of the belly (0.3-1.4 points) 6. better meat quality traits (pH-val ues 0.08-0.79 and meat brightness 2.5-12.3) According to the improveme nt of the meat quality not anyone of the NN-animals showed the PSE-def iciency, but 46.2% of the PP-genotypes developed this meat quality. 90 animals could be examined of stress-disposition by the CK-test. Only all of the PP-genotypes showed levels in the stress-susceptible range of greater-than-or-equal-to 3.0. The selection on homozygous stress-re sistant animals in a population leads to a conversion of the type of a nimals, however, there must not be expected a severe reduction in the performance traits of economical interest. The variation between the M HS-genotypes can be used to select NN-animals with high performance tr aits in every respect.