The aim of this study was to identify the association between single nucleotide polymorphisms (SNPs) in the bovine chemokine receptor (CXCR1) gene and the resistance or susceptibility of cows to mastitis. The analysis of the CXCR1 polymorphism was carried out using polymerase chain reaction restriction fragment length polymorphism analysis for six SNP mutations (c.+291C>T, c.+365T>C, c.+816C>A, c.+819G>A, +1093C>T, and +1373C>A), of which four were located within the coding region and two in the 3'UTR region of the CXCR1 gene. Genetic material from 146 Polish Holstein-Friesian cows was analyzed after dividing into two groups depending on the incidence of clinical mastitis. Identified polymorphisms were in linkage disequilibrium and formed two linkage groups. Three haplotypes (CCCATA, TTAGCC, CTCGCC), forming six haplotype combinations, were detected. The logistic regression showed a significant association between the CC genotype at c.+365T>C and susceptibility of cows to clinical mastitis (P = 0.047). The frequency of haplotype combination 1/1 (CCCATA/CCCATA) was not significantly higher in cows susceptible to mastitis (P = 0.062). Of the identified SNP mutations, only c.+365T>C is a nonsynonymous mutation that induces a change in the coded protein [GCC (Ala) to GTC (Val) at the 122nd amino acid]. This amino acid change can result in changes in receptor function, which may be a reason for the increased mastitis incidence observed in cows with polymorphism at this site.

Studies into the polymorphism of the bovine osteopontin (OPN) gene have so far been focussed on the association between milk production and milk composition, lactation persistency and the rate of growth and weight gain in young cattle. Results obtained by some authors have shown different associations for various milk parameters. Even though osteopontin is an essential component of immunological response, the relationship between the polymorphism of the osteopontin gene and the incidence of diseases in cows has not been researched as yet. The purpose of this study was to analyse the c.8514 C > T polymorphism and its association with milk parameters such as: average daily yield, average protein and fat percentage and average somatic cell count in Holstein-Friesian cattle. The study also included an analysis of the impact of polymorphism on the incidence of the most frequent cattle diseases such as: clinical mastitis (CM), ovarian cysts (OC), clinical hypocalcaemia (CH) and pyometra (P). The study population of cows was found to have two alleles in the analysed locus of the osteopontin gene: C (0.529) and T (0.471), and three genotypes: CC, CT and TT (0.288, 0.482 and 0.230, respectively). Although the study showed no significant association between the polymorphism of the OPN gene and the incidence of diseases or milk parameters, it is an important contribution to research aimed at identifying the most essential SNPs which could be used for marker-assisted selection in dairy cattle herds.

The aim of this study was to identify the c.495C > T polymorphism within exon 1 of the osteopontin gene (OPN), and to analyze its association with susceptibility to ketosis in Polish Holstein–Friesian (HF) cows. The study utilized blood samples from 977 HF cows, for the determination of β-hydroxybutyric acid (BHB) and for DNA isolation. The c.495C > T polymorphism of the bovine osteopontin gene was determined by PCR–RFLP. The CT genotype (0.50) was deemed the most common, while TT (0.08) was the rarest genotype. Cows with ketosis most often had the CC genotype, while cows with the TT genotype had the lowest incidence of ketosis. To confirm the relationship between the genotype and ketosis in cows, a weight of evidence (WoE) was generated. A very strong effect of the TT genotype on resistance to ketosis was demonstrated. The distribution of the ROC curve shows that the probability of resistance to ketosis is > 75% if cows have the TT genotype of the OPN gene (cutoff value is 0.758). Results suggest that TT genotype at the c.495C > T locus of the OPN gene might be effective way to detect the cows with risk of ketosis.

In the recent years, antioxidant properties of food products have become an important aspect for consumers. Milk is a very good source of easily absorbable proteins and minerals, as well as a valuable source of antioxidants. Lipocalin-2 (LCN2), given that, inter alia, it is produced in large quantities by various types of cells in response to oxidative stress caused by physical or chemical factors, it can be considered a protein that determines the total antioxidant capacity of milk. The main objective of this study was to analyze polymorphisms within the lipocalin-2 gene and to determine their impact on antioxidant activity of milk from Holstein-Friesian cows. The genotyping was carried out by sequencing of PCR products. To determine the antioxidant activity of milk, the Trolox equivalent antioxidant capacity (TEAC) method was used. A total of four polymorphic sites were identified in the examined segment of the bovine lipocalin-2 gene. It was shown that cows of the CC genotype at the locus g.98793763G>C produced milk of significantly higher antioxidant capacity. The antioxidant capacity of milk also varied according to the age of cows, their daily milk yield, and SCC in milk.

Purpose: The aim of the study was to analyse the quality changes in marinated herring meat depending on the moment of adding milk thistle.Design/methodology/approach: One control (C) and two experimental groups were investigated: MH (milk thistle added to a marinade solution) and FH (fillets rubbed with milk thistle before marination). The basic chemical composition, the meat colour, heavy metals concentration, fatty acids profile, quality of lipids and antioxidant capacity were determined.Findings: The occurrence of Fe, Mn, Cu and Zn was higher in the experimental group than in the control group throughout the marinating process. The peroxide value was higher from the first day in the control group than in the experimental groups. On the last day of the study, the peroxide value in the control group exceeded the maximum acceptable value. The highest level of Thiobarbituric Acid Reactive Substances was determined in the control group on the first day, and the lowest in the FH group. On the first day, the highest percentage of DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical quenching was recorded in the FH group.Originality/value: The results are the first to find that the addition of milk thistle to herring fillets in marinating process maintains or even improves the quality of the marinades. The process of previously coating the fillets in milk thistle and then marinating achieves a lower peroxide value, higher content of polyunsaturated fatty acids and a higher content of elements such as iron and manganese, which are very valuable for human health.