Jerzy Wójcik

Concentrations of toxic heavy metals and trace elements in raw milk of Simmental and Holstein-Friesian cows from organic farm.

Concentrations of toxic heavy metals (cadmium (Cd), lead (Pb)) and major nutritional and trace elements (Ca, Mg, P, Cu, Fe, Mn, Se, Zn) were analyzed in the milk of Simmental (n = 20) and Holstein-Friesian (n = 20) cows from an organic farm. Elements were determined using inductively coupled plasma emission atomic spectrometry. The conducted research showed that the milk of Simmental cows was characterized by the more advantageous mineral composition and lower concentration of noxious heavy metals compared to the milk of Holstein-Friesian cows. In the milk of Simmental cows, significantly lower concentrations of Pb and Cd (P < 0.001) and Cu (P < 0.05) and significantly higher concentrations of Fe and Mg (P < 0.05) as well as nonsignificantly higher concentrations of Ca, Mn, and Se were found. In the milk of both breeds, very low Cu concentrations were recorded. The higher-than-recommended concentration of Pb in milk was also found. In the milk of both breeds, the significant positive correlations between concentrations of the following elements were observed: Pb–Cd, Pb–Se, Cd–Se, Cd–Mn, Zn–Cu, Zn–P, Ca–P, Ca–Mg, and Mg–P. The correlations between other elements within each of the analyzed breeds separately were also found.

Heavy metals and other elements in serum of cattle from organic and conventional farms.

Concentrations of cadmium, lead, iron, zinc, copper, chromium, nickel, aluminium and arsenium were analysed in blood serum of cattle from organic (n = 20) and conventional (n = 21) farms. The elements were determined by inductively coupled plasma atomic emission spectrometry using an Optima 2000 DV instrument (Perkin Elmer Inc.). Animals from the organic farm were characterised by significantly lower (P < 0.01) serum concentrations of Pb, Zn, Fe, Cu, Cr, Ni, As and Al compared to animals from the conventional farm. The concentration of Cd was similar in animals from both organic and conventional farms. The concentration of toxic elements in cattle from organic and conventional farms studied was very low. The trace essential elements were generally within the adequate ranges except Zn and Cu, which were deficient. In organically reared animals, also serum Fe content was below the critical level for diagnosing iron deficiency. Pb was significantly correlated with Cd, Zn, Fe, Cu and Ni. A significant positive correlation between the concentration of Cd and Zn, Cu and Ni concentrations was only observed in cows from the organic farm. The present results suggest that organically raised animals are less exposed to harmful environmental influences such as the environmental pollution with heavy metals. On the other hand, these animals are at a greater risk of mineral deficiency compared to animals kept on conventional farms.

The PRNP ins/del and octapeptide repeat polymorphisms in Jersey cattle and their associations with production traits

So far the studies on the prion protein (PRNP) gene have mainly been focused on the search for an association between detected polymorphisms in this gene and the susceptibility of cattle to bovine spongiform encephalopathy. The PRNP gene location on chromosome 13 suggests that the polymorphisms within this gene can be potential quantitative trait locus (QTL) markers for milk production traits. The aim of this study was the analysis of the potential effect of the insertion/deletion polymorphisms within the promoter region (23 bp) and intron 1 (12 bp) of the PRNP gene on milk production traits in Jersey cattle. The study material consisted of 171 Jersey cows. The following milk production traits were analysed: milk yield, milk fat and protein yield, milk fat and protein content. Statistically significant differences were found in milk fat content in the second lactation between animal groups representing the ins/del and del/del genotypes for the 23 bp polymorphism (P≤0.05). The ins/del 12 bp polymorphism was found to have significant (P≤0.05) and highly significant (P≤0.01) effects on milk yield.