Influence of paratypes factors on the level of zinc in the lungs of the Hereford breed

Abstract

The study aims to evaluate the influence of the ecological and geographical factors on the zinc content of light Hereford bulls and calculate the reference intervals for this metal. Lung samples weighing 100 g were taken from clinically healthy bulls of the Hereford breed in the Maslyaninsky, Novosibirsk and Krasnozersky districts of the Novosibirsk region and the Tselinny district of the Altai Territory. The chemical composition of lung tissues was determined by atomic absorption spectrometry with electrothermal atomization. The homoscedasticity of dispersions in groups was assessed using the Fligner-Keelin test. The influence of the factor was determined using the Kruskal-Wallisl test. Multiple intergroup comparisons were made using Dunn’s test and Holm’s correction. The maximum zinc level was found in animals bred in the Maslyaninsky district (26.6 mg/kg) and the minimum – in Krasnozersky (13.8 mg/kg). Cattle from the Maslyaninsky district are characterized by higher phenotypic variability in zinc content in the lungs than in other areas. Generally, the variability of the studied metal in the lungs of gobies is relatively low. Group variances in the zinc level in cattle lungs are homoscedastic (x2 =2.27; P=0.518). The influence of the ecological and geographical factors on the zinc level in Hereford cattle’s lungs was established (H = 12.158; P = 0.007). The concentration of metal in the lungs of bulls from the Krasnozersky district is statistically significantly different from cattle from Maslyaninsky (Z = -2.96; P = 0.009). There were no statistically significant differences in Zn concentration in lung tissues between animals from other regions. Reference intervals for the content of zinc in the lungs of Hereford cattle in the conditions of the south of Western Siberia are 12.44-24.12 mg/kg, with 90% confidence intervals for the lower limit of 10.15-13.66 mg/kg and the upper limit of 22.73 -26.49 mg/kg.