: 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.

Ducháček J., Stádník L., Ptáček M., Beran J., Okrouhlá M., Čítek J., Stupka R. (2014): Effect of cow energy status on the hypercholesterolaemic fatty acid proportion in raw milk. Czech J. Food Sci., 32: 273-279.We evaluated the proportion of fatty acid groups, with an emphasis on hypercholesterolaemic fatty acids, in the milk of 25 Holstein cows during the 1 st period of lactation in relation to their negative energy balance (NEB). Sampling of each cow's milk started on the 7 th day after calving. Milk samples (n = 425) were collected at 7-day periods during the first 17 weeks of lactation. The proportion (%) of saturated (SFA), hypercholesterolaemic (HCFA), volatile (VFA), unsaturated (UFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids in the milk fat was determined. Body condition score and fat to protein ratio in milk were applied for precise determination of the NEB breakpoint during the observed period. The effects of parity, NEB, regression on lactation week and fat to protein ratio were evaluated using SAS 9.3. Milk contained a lower proportion of SFA as well as equally higher UFA (± 2.13%; P < 0.01) during the NEB period. The overcoming of NEB caused an increase in SFA, however, and simultaneously a significant decline in total HCFA (-1.86%; P < 0.01) as well as main MUFA (-1.81%, P < 0.05). The results document the necessity of increasing Holstein cow robustness to meet the production conditions in dairy farms in relation to the requirement of higher nutrient quality as well as the potential health benefits of cow's raw milk for consumers.

The objective of this study was to estimate genetic parameters for longevity and assess the suitability of using these selection criteria to improve the genetic merit of the beef cattle population of the Czech Republic. The performance record database, which contains records of 363,000 beef cattle animals of 19 breeds and their crosses, was used. The populations of Charolais and Aberdeen Angus were large enough that the genetic parameter estimations and all analyses were done for these breeds separately. Two similar approaches of longevity definition based on probabilities were considered as follows: productive longevity (PL), which is the number of calvings at target ages of 78, 90, 150, and 160 mo, and longevity (L), which is based on the probabilities of cow reappearance in the next parity. A multibreed single-trait animal model for L and a multitrait animal model for combinations of 78/150 and 90/160 mo for PL were used. Specific combinations of months were established based on the analysis and represented the critical culling rates in the studied population. The high genetic correlations (0.88-0.95) of the combination 90/160 suggested that the PL at 160 mo of age can be predicted on the basis of the value at 90 mo, which will make earlier selection possible. Combination 78/150 is less efficient in the Czech population of beef cattle due to the lower correlations (0.79-0.93) between traits. The estimated heritabilities were low for both traits (below 0.14), but the additive genetic variance was sufficient for identifying animals with high genetic merit.

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.