: We analysed the relations of estimated breeding values (EBV) of 315 German Holstein sires to their genotypes in growth hormone gene (<i>GH1</i>), growth hormone receptor gene (<i>GHR</i>) and acylCoA-diacylglycerol acyltransferase 1 (<i>DGAT1</i>). The strong relation of <i>DGAT1 K232A</i> to the estimated breeding values for milk production traits has been confirmed, when allele <i>DGAT1^K</i> was connected with higher milk fat yield, milk fat and milk protein content, while allele <i>DGAT1^A</i> increased milk yield and milk protein yield. The effect of <i>DGAT1</i> genotype explained from 4.70% of variability of EBVs for fat yield to 31.90% of variability of EBVs for fat content. The evaluation of <i>GH1</i> 127 Leu/Val and <i>GHR</i> 257 SNP polymorphisms did not reveal an association of their polymorphism with EBVs for milk production traits, except the EBVs of <i>GHR^G/GHR^G</i> homozygotes for fat yield, which were significantly lower. The effect of <i>GH1</i> or <i>GHR genotype explained only a negligible portion of variability of EBVs (<i>R</i>² < 1.00% in most cases).

A screening was carried out for CVM, BLAD, DUMPS, bovine citrullinaemia, glycogen storage disease V, and Robertsonian translocations in the cattle population of the Czech Republic. In 406 Holstein sires and 146 Czech Pied (Czech Simmental) sires entering the AI programme in the Czech Republic from [2003][2004][2005], no heterozygous sire for DUMPS, bovine citrullinaemia and BLAD was found. The heterozygote was not found also in the beef sires of Charolais, Limousine, Beef Simmental, Blonde d'Aquitaine, Belgian Blue, Aberdeen-Angus, and Hereford breeds. In 111 elite Holstein females, 21 (18.9%) were heterozygotes for CVM, and were dominant homozygotes for BLAD, DUMPS and bovine citrullinaemia. In the myophosphorylase gene responsible for the glycogen storage disease V, in the Charolais (n = 30), Czech Pied (n = 53), and Belgian Blue, Limousine, Blonde d'Aquitaine, Aberdeen Angus, and Beef Simmental sires analysed, the heterozygote was not found. Robertsonian translocations were examined in 767 Holstein sires, 1 010 Czech Pied (Simmental) sires, 142 beef sires, and 48 dams. Of these, 10 sires of Czech Pied breed, 5 beef sires, and 13 females were found to be positive. The monitoring of BLAD, CVM, and Robertsonian translocations is recommended.

Insulin-like growth factor-I gene polymorphism and its association with growth and slaughter characteristics in broiler chickensChicken insulin-like factor 1 gene (IGF1) is a biological candidate gene for the investigation of growth, body composition, and metabolic and skeletal traits, and is also a positional candidate gene for growth and fat deposition in chickens. Two broiler populations Ross 308 and Cobb 500 were used to study the relationship between IGF1 gene polymorphism and phenotypic traits. A single nucleotide polymorphism (SNP) was identified in 132 individuals using the PCR-RFLP technique. Genotypical frequencies were, for genotype AA: 0.83-0.86, and for AC: 0.14-0.17. Associations between IGF1 promotor polymorphism and liver weight (P≤0.05) and liver weight as a percentage of the weight of the poultry carcass with the giblets (P≤0.05), were found in the AC genotype in a comparison of broiler homozygous chickens AA in the Cobb 500 line. In these broilers, the breast muscle and leg muscle weight in the AC genotype were higher, and abdominal fat weight lower compared with AA genotype chickens, but these differences were not significant.

ABSTRACT:The aim of the paper was to analyse congenital disorders in the Czech cattle population in 1986-2001. The offspring of 474 sires -215 Czech Simmental, 236 Holstein, and 23 beef -were diagnosed with congenital disorders which were unevenly distributed because only 18 occurred in the progeny of 10 and more sires, in contrast to 88 occurring in the progeny of 1 sire only. Umbilical hernia was the most frequently noted disorder, and 136 sires fathered progeny with limb anomalies. The most frequent gestational accident was schistosomus reflexus, the results suggesting a familial burden. Three sires fathering offspring with the afflicted spinal column and limbs were heterozygous for Complex Vertebral Malformation (CVM) though they had not been reported as such. Foetal defects and stillbirth were quite frequent, and the calves affected were fathered by 56 sires. In rare disorders with a low incidence, an accurate genetic analysis or even simple discrimination between inherited and acquired defects is problematic. It would be our recommendation that those sires with a higher incidence of defects among their offspring should be disqualified from fathering stock bulls, or culled.

A set of 233 Holstein calves, their 233 dams and 44 sires from 4 large-sized herds was genotyped for 10 microsatellites recommended by ISAG for paternity/parentage testing. Heterozygosity of microsatellites ranged from 0.607 (SPS115) to 0.835 (TGLA227), and PIC from 0.575 (SPS115) to 0.816 (TGLA227) confirming a high polymorphism of each analysed locus. Their combined exclusion probability reached 0.999, which made them suitable and sufficiently accurate for parentage testing. A conflict between putative parents and calf in at least 2 markers with combined exclusion probability > 0.9 was required to reject parentage. The pedigree was considered incorrect in 25 (10.73%) out of the evaluated progeny/parent trios, of which in 10 samples the genotype of both parents did not match their offspring, and in 2 samples the putative dam was in conflict with the calf genotype. This result shows that the interchange of calves on farms with large-sized herds plays the role as important as the errors in sire identification, or recording mistakes.