ABSTRACT:The impact of polymorphism of the diacylglycerol acyltransferase (DGAT1), butyrophilin (BTN1A1), oxidized low-density lipoprotein receptor (OLR1), and signal transducer and activator of transcription 1 (STAT1) genes on milk production and reproduction traits in 419 Czech Fleckvieh cows was examined using polymerase chain reaction and restriction fragment length polymorphism. The loci DGAT1 and BTN1A1 were observed simultaneously to affect milk production, estimated breeding value of milk production traits, as well as reproduction parameters. Significant differences were found also between genotypes of the STAT1 loci in relation to estimated breeding value of milk production traits. Similar findings in pure dairy breeds suggest that heterogeneous effects of the observed loci can be explained by different genetic backgrounds in various breed populations selected to achieve different commercial goals. Thus, it is necessary to determine variability and influence of a molecular marker in a specific population when considering its inclusion into a breeding programme.

This study compares the genetic variation in seven cattle breeds from theterritory ofCentralEurope. Eleven polymorphic microsatellite loci were used to detect differences in the polymorphism of genetic markers in Czech Pied (Simmental), Slovakian Pied (Simmental), Slovakian Pinzgau,Holstein, Polish Red, German Red, and Czech Red breeds. For these loci, allele frequencies, heterozygosity, polymorphism information content, effective population size, and genetic distances were evaluated. The phylogenetic tree was constructed using the unweighted pair group method with arithmetic mean and it showed that the Central European Red breeds tended to cluster together, whereas theHolstein was the most divergent from the remaining breeds. These data are discussed in the context of the known origin of respective breeds.  

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ObjectiveThe use of genetic markers can help to enhance reproduction in cattle, which is a very important trait for profitability in dairy production systems. This study evaluated the association between genotypes of leptin (LEP), toll-like receptor 4 (TLR4), and chemokine receptor of interleukin 8 C-X-C motif (CXCR1) genes and fertility traits in Czech Fleckvieh cattle.MethodsPhenotypic data from 786 Czech Fleckvieh cows raised on 5 farms in the Czech Republic were used, along with information from the 1st three parities. To determine genotype, the polymerase chain reaction– restriction fragment length polymorphism method was used.ResultsExcept for LEP g.-963C>T, all studied genotype frequencies of single nucleotide polymorphisms (SNPs) were distributed according to the Hardy-Weinberg equilibrium. Two LEP SNPs (g.-963C>T and c.357C>T) were associated with the age at the 1st calving, days open (DO), pregnancy rate after 1st service (PR), and calving interval (CLI). In LEP g.-963C>T the TT genotype heifers firstly calved 24 days earlier than CC genotype and the CT genotype cow showed a tendency for shorter DO and higher PR. In LEP c.357C>T we observed longer CLI and DO period in TT cows. In general, we can propose the TT genotype of g.-963C>T as favorable and the TT genotype of c.357C>T as unfavorable for a cow’s fertility. Heterozygotes in TLR4 c.-226C>G were significantly associated with shorter CLI, and presented a nonsignificant tendency to be associated with higher PR. In CXCR1 c.777 C>G, we did not observe any relationship of this SNP with reproduction.ConclusionOverall, the results showed that LEP could be an effective marker for improving reproduction in Czech Fleckvieh cattle. This study also provides novel insights into the relationship between TLR4 and CXCR1 SNPs and reproduction in dual-purpose cattle.

The goal of this work was to develop a protocol for rapid genotyping of A and G variants at the CSN2 locus and genotyping of T and C variants at the CSN3 locus in sheep breeds (Sumava and Valachian) by means of PCR and LightCycler analysis. The LightCycler technique combines rapid and efficient in vitro amplification of DNA in glass capillaries with melting curve analysis based on fluorescence resonance energy transfer for the sensitive detection of point mutation. The A variant had a greater frequency (Sumava, 0.778; Valachian, 0.835) than did variant G (Sumava, 0.222; Valachian, 0.165) in both sheep breeds. The CSN3 locus was found to be monomorphic, with no polymorphism identified in either population.