Imprinted genes are involved in many aspects of development in mammals, plants, and perhaps birds and may play a role in growth and carcass composition of slaughter animals. In the presence of genomic imprinting the expression and, consequently, the effect on the phenotype of maternal and paternal alleles are different. For genetic evaluation genomic imprinting can be accounted for by incorporating 2 additive genetic effects per animal; the first corresponds to a paternal and the second to a maternal expression pattern of imprinted genes. This model holds whatever the mode of imprinting may be: paternal or maternal, full or partial, or any combination thereof. A set of slaughter data from 65,233 German Simmental fattening bulls was analyzed with respect to the relative importance of the genetic imprinting variance. Besides slaughter weight, net daily BW gain, and killing out percentage, there were 22 other traits describing the carcass composition. The latter traits were evaluated by automatic video-imaging devices and were composed of weights of valuable cuts as well as fat and meatiness grade. The number of ancestors in the pedigree was 356,880. Genomic imprinting significantly contributed to the genetic variance of 10 traits, with estimated proportions between 8 and 25% of the total additive genetic variance. For 6 of these traits, the maternal contribution to the imprinting variance was larger than the paternal, whereas for all other traits the reverse was true. Fat grade only showed a paternal contribution to the imprinting variance. Estimates of animal model heritabilities of automatic video-imaging-recorded carcass traits ranged between 20 and 30%.

Abstract. Title of the paper: Association of polymorphisms in the promotor region of porcine HSP70.2-gene of boars to litter size Heat shock protein genes 70 are candidate genes for the general constitution of farm animals because the physiological function of their proteins in the stress processing. Polymorphisms in the promotor region of the porcine HSP 70.2 gene could be usable as indicators of this function for breeding. This work studied the dispersion of the genotypes of two polymorphisms and their association to the number of living born piglets per litter and to the number of weaned piglets per litter using a material of 169 boars with more than 22000 litters. Differences of the distributions of genotypes and alleles within and between breeds indicate a general importance of these polymorphisms for breeding with pigs. The estimated gene substitutions effects show an improved fertility if the mutated alleles appear in heterozygous genotypes. The substitution effects were however low and could not be secured statistically.