Polimorfizam gena OLR1 i funkcionalna svojstva mliječnih krava

The study analyzed the polymorphism of single nucleotide substitution A8232C, located in the 3’UTR region of the receptor of the oxidized low-density lipoprotein (OLR1) gene. The study was conducted in a herd of Polish Holstein-Friesian (Red-and-White strain) dairy cattle. Identification of genotypes of individuals was performed using PCR-RFLP. The study stated the following frequency of A8232C polymorphism alleles: A - 0.30 and C - 0.70. Statistical analysis showed that the AC genotype cows were characterized by higher milk yield, protein and fat and for fat yield, the difference was confirmed statistically (P≤0.05). The cows with genotype AA were characterized by the latest occurrence of first calving and the longest intercalving interval, but the results were not confirmed statistically.Analiziran je polimorfizam pojedinačnog nukleotida na poziciji A8232C, smještenog u regiji 3’UTR, gena za receptor oksidiranog lipoproteina male gustoće (OLR1). U stadu poljskih holštajnsko-frizijskih (crveni i bijeli soj) krava za mlijeko genotipovi jedinki identificirani su PCR-RFLP metodom. Ustanovljena je sljedeća učestalost A8232 polimorfnih alela: A - 0,30 i C - 0,70. Statistička je analiza pokazala da su krave s genotipom AC imale veću proizvodnju mlijeka, bjelančevina i masti, pri čemu je razlika za mast potvrđena kao signifikantna (P≤0,05). Krave s genotipom AA imale su kasno prvo teljenje i dugo međutelidbeno razdoblje, no ti rezultati nisu potvrđeni kao statistički signifikantni

Utjecaj učestalosti mužnje na količinu, kemijski sastav i kvalitetu mlijeka

The aim of this study was to compare daily yield, milk composition and somatic cell count after increasing milking frequency from twice to three times a day. The study also includes the effect of other factors such as: the sequence of lactation (1, 2, ≥3) and the period of lactation (100 days, 101-200 days, 201-300 days, and more than 300 days). In conclusion, it should be noted that increasing the frequency of cow milking had a positive effect both on the milk yield (P≤0.01), causing a substantial increase, as well as on the cytological quality of produced milk. The somatic cell count (1000/mL) was lower in the group of cows milked three times a day. All the data regarding farming records of this farm came from the SYMLEK system maintained and made available by Polish Federation of Milk Producers and Cattle Breeders (PFHBiPM). Analysis of useful milk traits included: daily yield, fat, protein, dry matter and somatic cell count in milk.Cilj ovog istraživanja bio je usporediti dnevnu količinu mlijeka, sastav mlijeka i broj somatskih stanica nakon povećanja učestalosti mužnje s dva na tri puta. Studija je također uključila i druge čimbenike: redoslijed laktacije (1, 2, ≥3) i razdoblje laktacije (do 100 dana, 101-200 dana, 201-300 dana, i više od 300 dana). Zaključno, treba napomenuti da povećanje učestalosti mužnje krava ima pozitivan učinak i na količinu mlijeka (P≤0,01), što uzrokuje značajno povećanje, kao i na citološku kvalitetu proizvedenog mlijeka. Broj somatskih stanica (1000/mL) bio je manji u skupini krava koje su bile na mužnji tri puta. Svi podaci prikupljeni su iz sustava dokumentacije SYMLEK, osigurane iz zajedničke dokumentacije uzgojne grane privrede, koju vodi Poljsko udruženje stočara i proizvođača mlijeka (PFHBiPM). Analiza je uključivala: dnevnu količinu, količinu masti, proteina, suhe tvari kao i broj somatskih stanica u mlijeku

Relationship between milk protein polymorphism and selected cows’ reproductive indices

This research sought to determine the effect of selected milk protein polymorphisms on the reproduction parameters of 598 black and white Polish Holstein–Friesian cattle. The analyzed genes were kappa-casein (CSN3) and beta-lactoglobulin (BLG). The following reproductive indexes were selected: the age at first calving, the interpregnancy period, the calving interval, and the insemination index. The influence of the identified genotypes on the course of parturition in cows was also analyzed. Source data were collected for each cow from the beginning of the herd life and reproduction to its culling from the herd or the end of its third lactation. Data on the age at first calving, the amount of semen portions for artificial insemination (insemination index), the interpregnancy period, and the calving interval for each cow were also collected. A contingency analysis was performed through contingency tables using a Pearson’s chi-squared test for each CSN3 and BLG genotype. The results show that the BB genotype of the kappa-casein gene was associated with the most favorable values of reproductive indicators. In the case of the calving interval, the values were significantly more favorable than those of other genotypes (p 0.05). No effect of beta-lactoglobulin polymorphism on the analyzed reproductive indices was observed. On the other hand, in the case of the interpregnancy period, significant statistical differences were obtained between the AA and BB genotypes. The analyzed kappa-casein and beta-lactoglobulin genotypes did not significantly influence the course of parturition in cows. To conclude, the genotype polymorphism BB CSN3 is the most favorable for the performance of the cows in the examined herd.info:eu-repo/semantics/publishedVersio

Effects of Single Nucleotide Polymorphisms in the SLC27A3 Gene on the Nutritional Value of Sheep Milk

The current research was undertaken to use the genetic potential of animals to obtain high-quality dairy products. Single nucleotide polymorphisms (SNPs) in SLC27A3 gene were identified in Zošľachtená valaška sheep using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Correlations between genotypes and milk composition and nutritional value were analysed This study showed that milk from sheep with TT genotype in the SNP4 locus was characterised by higher (p < 0.01) fat and dry matter content and lower lactose concentration, compared to sheep with AA and TA genotypes, respectively. Moreover, it was found that animals with GG genotype in SNP1 produced milk with higher C18:1n9c, C18:1n7t, CLA, and other unsaturated fatty acids (UFAs) content than sheep with TT. Additionally, milk from animals with CC at the SNP3 locus had significantly higher (p < 0.01) levels of UFAs than milk from sheep with other genotypes in the SNP3. In summary, it may be concluded that milk from animals with TT genotype of SNP4 is characterised by higher fat and dry matter content. Whereas, milk from sheep with GG in SNP1 and with CC in SNP3 is characterised by higher content of UFAs, which increases milk value as material for functional food production

Influence of milk, milk fractions and milk proteins on the growth and viability of mastitis-causing Staphylococcus aureus strain

The aim of this study was to investigate the impact of milk and milk fractions (cell-reduced, skim and whey) obtained from different cows on the growth rate of mastitis-causing Staphylococcus aureus strain at low inoculum density, simulating the early phase of intramammary infection. The association of the selected milk proteins, including α-lactalbumin, β-lactalbumin, lactoferrin, bovine serum albumin, γ-globulin and casein with the bacterial growth was also analysed. Twelve Polish Holstein-Friesian cows having no history of mastitis during the previous and current lactation were selected for this study. The S. aureus strain used in this study was isolated from a cow with clinical mastitis and was characterised by confirmed ability to spread among cows within a herd. Linear regression coefficients were calculated for associations between milk constituents and bacterial counts in whole milk as dependent variables. The comparison of bacterial growth between whole milk, cell reduced, skim and whey fractions was determined by a one-way analysis of variance (ANOVA). The results of the present study showed that the growth of mastitis-causing S. aureus was less stimulated by whole milk samples and their individual fractions in comparison to the nutrient microbiological medium. The strongest inhibition of bacterial growth was observed for whey fraction. Lactoferrin was the only protein causing a slight decrease in the growth of S. aureus. It was concluded that, depending on its growth medium and antimicrobial properties, milk may be among the factors of key importance for the incidence of this disease among individual cows

Relationships between Selected Physiological Factors and Milking Parameters for Cows Using a Milking Robot

The aim of the study was to determine the effect of the number and stage of lactations, time of day and calving season of cows on milk yield from a single milking, average milking time, average milking per minute, daily milking frequency and the relationship between the tested parameters of quarter milking. The study included a herd of 65 Polish Holstein Friesian black and white cows used in a free-range barn located in south-west Poland. The animals were kept in proper welfare conditions, fed using the partly mixed ration (PMR) method on the feeding table. The milk was obtained using the Lely-Astronaut A4 Automatic Milking System (AMS). The animals on the dairy cattle farm were used in the range from the first to the seventh lactation, i.e., at the age of 2.0 to approximately 10 years. In this study, the amount of milk yielded from the hind quarters was statistically significantly higher (p < 0.05) than the trait determined for the front quarters. At the same time, the milk flow rate was statistically significantly higher (p < 0.05) in the front quarters compared to the rear quarters. The daily milk yield in right rear (RR) and left rear (LR) hind quarters was higher by 1.0 kg of milk, respectively, than in right front (RF) and left front (LF) fore quarters. The milking time of the RR and LR hind quarters during the day was longer by 104.9 and 128.8 s, respectively, than the RF and LF fore quarters. The milking speed of the RR and LR hind quarters during the day was lower by 0.2 and 1.12 g/s, respectively, than in the RF and LF fore quarters. The values of the correlation between the yields of milk and its components obtained in this study were high and positive. Correlations between the milk yield and the content of its components were negative. The obtained results confirmed that the natural physiological variability of the udder and teats structure, as well as the course of lactation, significantly affects the individual composition and milk flow during milking. The ability to regulate the milk flow by adjusting the appropriate negative pressure during the robot’s operation, in the observed variability of individual lobes of the mammary gland, increases the efficiency of milking and, as a result, reduces the risk of mastitis in cows

Examination of the haematological profile of pregnant Polish Holstein-Friesian black-and-white cattle in the early stage

Cattle health and welfare are monitored via the analysis of the haematological profile, and it shows cattle’s ability to adapt to changing environmental conditions, pregnancy and lactation; profile changes also indicate reproductive disorders. The literature lacks reports of the examination of the haematological profile in cows up to the 50th day of pregnancy (dop). Therefore, this research examined that in cows up to this pregnancy stage

ASP

Abstract. The aim of the present study was to determine the frequency of the two polymorphic variants located in intron 4 of the gene coding for insulin-like growth factor 1 receptor (IGF1R) in the examined herd of 184 Holstein-Friesian cows and to search for the association between these polymorphisms and the selected milk performance traits. The IGF1R gene polymorphism was identified with PCR-RFLP using the HinfI and Mph1103I restriction enzymes. For the IGF1R/HinfI polymorphism, the highest frequency was found for the BB genotype (0.49), a similar one was in the case of the AB genotype (0.45) and the lowest one was for the AA genotype (0.04). The frequency of alleles was as follows: allele A -0.28 and allele B -0.72. Statistical analysis showed that the analysed polymorphism significantly affected milk yield, milk protein yield (P≤0.01) and milk fat yield (P≤0.05), favouring the BB genotype. For the IGF1R/Mph1103I polymorphism, no individuals with the AA genotype were recorded. A high frequency of allele B (0.94) was found. No significant effect of the IGF1R/Mph1103I polymorphic site on the yield of milk, fat and protein was shown. Statistically significant differences (P≤0.05) were observed only for the percentage content of milk fat and protein with indication on the positive effect of the BB genotype