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The aim of this paper was to evaluate the effect of genetic polymorphism of kappa-casein on milk production in Holstein cattle. Two hundred and ten Holstein cows were used in this study. We established genotype structure of cattle population and calculated allelic frequencies based on PCR-RFLP analyses. The three genotypes: AA (69.52%), AB (27.62%), and BB (2.86%) were detected. Frequency of allele A was 83.33%, and of allele B 16.67%. The Holstein cattle kept in Slovak Republic exhibit a high value of homozygosity (0.7222) and low values of polymorphism information content (0.2392), effective number of alleles (1.3847) and level of possible variability realization (27.91%). The effect of polymorphism of CSN3 gene on average breeding values for milk production traits, such as yield of milk, fat and protein expressed in kilograms, as well as percentage content of fat and protein in milk, has been assessed. In our assessment of the observed traits' variability's dependence on CSN3 gene polymorphism, we detected a statistically significant difference between genotypes only in case of the average breeding value for the percentage of protein in milk.

Coconut oil has a high content of lauric acid, which has selective antibacterial activity. This study aimed to explore the effect of coconut oil ingestion on the gastrointestinal microbiomes of pigs. A 14-day-long feeding experiment included 19 pigs in two groups (9 on a normal diet and 10 on a diet supplemented with coconut oil). At the start and end of the experiment, a rectal swab sample was taken from each pig in both groups, and total bacterial DNA was extracted. We used 16S rRNA high-throughput amplicon sequencing to evaluate the microbiome changes during the feeding experiment. A total of 446 operational taxonomic units (OTUs) were detected in the whole sample set. Shannon’s indices of bacterial diversity did not change significantly during the experiment. Changes in the bacterial community during the study period and in response to the coconut oil treatment were highly significant (p < 0.001). During the study, an increase in the abundance of Lactobacillus was detected in the group treated with coconut oil. An increase in Alloprevotella, Bifidobacteriales, and Lactobacillales and a decrease in Corynebacterium, Mitsuokella, Psychrobacter, and Pseudomonadales were attributed to the coconut oil treatment. Although the addition of coconut oil to pig feed did not affect Shannon’s index of diversity, it had a positive effect on the abundance of bacterial groups that are considered to be commensal and/or probiotic.

The goal of the paper was to identify genetic structure of five candidate genes for milk production in Slovak Pinzgau breed. A total of 86 mothers of bulls of Slovak Pinzgau cattle were use in this study. To genotype of cows for candidate genes we used PCR methods (PCR-RFLP, ARMS-PCR, multiplex PCR-RFLP). On the basis of PCR analyses we established genotype structure of cattle population and calculated allelic frequencies. Effectiveness of allele incidence and genetic diversity was evaluated with following parameters: theoretical heterozygosity (He exp), experimental heterozygosity (He obs), polymorphism information content (PIC), expected homozygosity (E), effective number of alleles (ENA), level of possible variability realization (V%). Slovak Pinzgau cattle exhibit the high values of heterozygosity, polymorphism information content, effective number of alleles and level of possible variability realization for genes CSN2, CSN3 and LALBA. In opposite, for genes CSN1S1 and LGB show high values of homozygosity.

The goal of work was identification A1 variant of bovine beta casein which involves ischemic heart disease and diabetes mellitus in human. The digestion of A1beta casein can result in the production of bioactive beta casomorphin-7 (BCM-7); this is not the case with A2. This bioactive peptide has been linked to physiological traits that may elicit effects on components of the vascular and immune systems. The material involved 111 Slovak Spotted breed. Bovine genomic DNA was extracted from whole blood by using commercial kit, and used in order to estimate beta-casein genotypes by means of PCR-RFLP method. The PCR products were digested with DdeI restriction enzyme. In the population included in the study were detected all three genotypes, homozygote genotype A1A1 (14 animals), heterozygote genotype A1A2 (37 animals) and homozygote genotype A2A2 (60 animals). In the total population of cattle homozygotes A2A2-0.5405 were the most frequent, while homozygotes A1A1-0.1261 were the least frequent ones. This suggests a superiority of allele A2 (0.7072) which does not produce BCM-7, and thus is safe for human consumption. The expected homozygosity for gene CSN2 is in the population stated a slight increase in homozygosity (0.5858). This caused a slight decrease in the level of possible variability realization (41.80%), which corresponds to the effective number of alleles (1.7071).

The objective of this study was to apply high resolution melting analysis in the detection of complex vertebral malformation (CVM) carriers in Hosltein cattle. A total of 47 animals of Holstein cattle were included in this study. Genomic DNA was extracted from blood, hair follicles and sperm by commercial QIAamp® DNA Mini kit. The amplification and high resolution melting analysis (HRMA) was done by commercial SensiMixTM HRM kit. The confirmation of sensitivity of this method was done by PCR-PIRA method and sequencing. Four samples of heterozygous genotype GT for causal mutation in the bovine solute carrier family 35 member 3 gene (SLC35A3), which is responsible for CVM disease, were detected. Our results demostrated that the use of HRMA for genotyping of mutant allele T for SLC35A3 gene in Holstein cattle is an effective method for the selection of carriers of CVM disease

The aim of this study was to identify the K232A polymorphism in gene encoding diacylglycerol O-acyltransferase 1 (DGAT1) and to evaluate its effect on carcass traits in population of Slovak Pinzgau steers. The genotyping data were obtained for totally 56 animals by using PCR-RFLP method. The A allele (0.93) was more frequent in analysed population than K allele (0.07). Even if the expected and observed heterozygosity indicated prevalence of homozygotes, the significant effect of inbreeding on population structure wasn't found (FIS=-0.08). The decline in effective allele number (Na=1.15) as well as polymorphic information content (PIC=0.12) pointed out to significant decrease of locus effectiveness in population. The effect of DGAT1 gene polymorphism on carcass traits was tested by using the GLM procedure adopted in SAS 9.3. In association analysis the proportion of muscle, fat, bone, and drip loss within the beef three-rib section were evaluated. However, the statistical analysis showed only non-significant impact of DGAT1 gene polymorphism on selected production traits in analysed population.

Bacterial contamination of semen is an important factor connected to the health status of bulls that may significantly affect semen quality for artificial insemination. Moreover, some important bovine diseases may be transmitted through semen. Up to now, only a very limited number of complex studies describing the semen microbiome of bulls have been published, as many bacteria are hard to cultivate using traditional techniques. The 16S rRNA high-throughput sequencing strategy allows for the reliable identification of bacterial profiles of bovine semen together with the detection of noncultivable bacterial species. Fresh samples from Holstein Friesian breeding bulls (n = 55) were examined for the natural variability in the present bacteria. Semen doses were selected randomly from Slovak Biological Services in Nitra, Slovak Republic. The most predominant phyla within the whole dataset were Firmicutes (31%), Proteobacteria (22%), Fusobacteria (18%), Actinobacteria (13%) and Bacteroidetes (12%). Samples of semen were divided into two separate clusters according to their microbiome compositions using a cording partition around a medoids analysis. Microbiomes of the first cluster (CL1) of samples (n = 20) were based on Actinobacteria (CL1 average = 25%; CL = 28%) and Firmicutes (CL1 = 38%; CL2 = 27%), while the second cluster (CL2; n = 35) contained samples characterized by a high prevalence of Fusobacteria (CL1 = 4%; CL2 = 26%). Some important indicator microbial groups were differentially distributed between the clusters.