Given the growing interest of consumers in naturally produced meat, we decided to examine the muscles of Ross 308 broiler chickens kept in an ecological system, with the division into two research groups depending on sex. All the analyses were carried out using the appropriate methods recommended by the AOAC and in accordance with the Polish standards (PN), which are described in detail in the relevant section of the publication. The aim of the experiment was to investigate the effect of sex on the growth performance, carcass traits and meat quality, as well as the fatty acid profile and histological parameters, of the pectoral muscles from organic broiler chickens. A total of 60 one-day-old Ross 308 chickens (half males and half females) were divided into two groups, according to the sex, and reared under organic conditions (Org.) until 82 days of age (ten birds, i.e., five males and five females in each of three pens; replications for experimental groups). Compared with the female group, the male group had a higher final BW and carcass weight (p < 0.05). The males had a better growth and slaughter performance than the females. The meat quality traits and fatty acids content were also affected by sex. The meat from females showed a significantly higher (p < 0.05) protein, dry matter, fiber diameter and shear force and a significantly lower (p < 0.05) fat level than the male group. In this research, the suitability of these fast-growing broilers for natural and organic production systems has been researched with regard to the performance, meat quality and histological characteristics of the muscles.

The aim of the study was to investigate the effects of age and sex on the content of heavy metals (Pb, Cd, Zn and Cu) in the hair, liver and the longissimus lumborum muscle of roe deer (Capreolus capreolus L.). In addition, correlations between heavy metals in individual tested matrices were studied as well as an attempt was made to explain the reasons for their accumulation in specific research matrices. The levels of Zn and Cu were measured using atomic absorption spectroscopy (F-AAS). The levels of Pb and Cd were analysed by means of electrothermal atomic absorption spectroscopy (ET-AAS). In the own research, sex-related statistically significant differences in concentrations of analysed elements were confirmed. Higher levels of the elements were observed in samples collected from does (except for Cd in the liver samples of 6–7-month-old male fawns) but only in some cases, these values were statistically significantly higher. In some cases, age-related differences in the content of individual metals were also confirmed. Age-dependent increased Pb levels in the muscle and liver were reported in 6–7-month-old, <3–4-year-old, <5–6-year-old males. Similar relationships were confirmed for Zn in the bucks’ muscles. In the group of does, the increase in heavy metal concentrations with aging was observed for Zn in the muscle and for Pb in the liver. In the other cases, the trend of age-related level changes regarding heavy metals was not clearly demonstrated. Significant positive correlations between Cu and Cd were found for all samples, and significant negative correlations of Cu with Pb were found for the hair and liver. There was a negative correlation of Zn with Cu in all matrices. The study also revealed a negative correlation between Zn and Pb in muscle and a strong significant negative correlation between Zn and Cd in hair and in the liver.

The aim of the study was to analyse correlations and variability between the levels of mineral elements (Fe, Mn, Zn, Cu, Na, K, Ca and Mg) and toxic metals (Pb and Cd) in the longissimus lumborum muscle, hair and selected organs of red deer (Cervus elaphus L.). The levels of mineral elements were measured using atomic absorption spectroscopy (F-AAS). The levels of Pb and Cd were analysed by means of electrothermal atomic absorption spectroscopy (ET-AAS). Of all analysed microelements, the highest concentration (in g·kg⁻¹ of dry weight) was found for Fe in the liver. Considering all macroelements, the highest level was found for K in the longissimus lumborum muscle. Particularly remarkable was the high level of Pb in the muscle and hair of red deer. The level of Cd in the hair was four to five times lower than in other samples. The study revealed many significant correlations between the levels of certain elements in individual tissues and organs. There were significant correlations between Cu-Fe (r_xy = 0.650; p ≤ 0.01), Pb-Cu (r_xy = −0.863; p ≤ 0.01) and Cd-Ca (r_xy = −0.743; p ≤ 0.01) in testicles. For kidneys, a significant negative correlation was found for K and Na (r_xy = −0.779; p ≤ 0.01) and for Ca and Cd (r_xy = −0.695; p ≤ 0.01), and a positive correlation between Cu and Mn (r_xy = 0.693; p ≤ 0.01). In the liver, significant negative correlations were found between Ca-K (r_xy = −0.654; p ≤ 0.05), Cd-Fe (r_xy = −0.651; p ≤ 0.05) and Pb-Cu (r_xy = −0.627; p ≤ 0.05). In the muscle, only single significant correlations were found between Cd and Mn (r_xy = 0.648; p ≤ 0.05). The highest number of significant correlations were recorded for the hair, among others between Na-K (r_xy = 0.760) and Ca-Zn (r_xy = 0.709) at p ≤ 0.01. The study revealed high variability in the levels of mineral elements and selected toxic metals in tissues, organs and hair of red deer. Additionally, this research confirmed that the accumulation of a specific metal in a tissue or organ can reduce its concentration in another matrix or promote its increased content in another tissue or organ.

The trial was conducted in order to evaluate the effect of the rearing system and sex on live body weight, daily weight gain, carcass traits and meat quality of broiler chickens. Sixty 1-d-old Ross 308 chickens (males and females) were randomly divided, according to the sex, into 2 experimental groups based on rearing system: intensive system (IS; n = 30), birds reared till 42 d of age and semi-intensive system (SIS; n = 30), birds reared till 56 d of age. Compared with SIS group, IS group had higher (P < 0.01) daily weight gain, weight and yield of pectoral muscle (PM). Differently, SIS group had higher (P < 0.05) carcass weight and carcass yield. Males have usually a better performance than females. In comparison with IS, SIS exhibited a lower (P < 0.01) breast meat pH and higher (P < 0.01) lightness and yellowness values. Pectoral muscle from IS broiler chickens showed a greater (P < 0.01) fibre diameter and significantly higher shear force values than PM from SIS chicken. PM from IS chicken group had higher (P < 0.01) dry matter and protein content and slight fat content than PM from SIS chickens. The sex influence was not observed on physicochemical characteristics of PM in chickens reared in both system.

The aim of the research was to determine the influence of geographical location on the content of mineral elements (Zn, Cu, Mn, Fe, Ca, Mg, Na, K) and heavy metals (Pb and Cd) in the hair of red deer (Cervus elaphus L.). The experimental material comprised samples of hair collected from 2-3-year-old male red deer from three Polish provinces: Kuyavian-Pomeranian (n=15), Lesser Poland (n=15) and Masovian (n=15). The analysis of content of Zn, Cu, Mn, Fe, Ca and Mg was conducted by means of atomic absorption spectroscopy (AAS), and in the case of Na and K – of atomic emission spectroscopy (AES). The content of Pb and Cd was determined in a certified laboratory, using electrothermal atomic absorption spectroscopy (ASS-ET). The highest concentration of Pb was noted in the samples from the Masovian Province and Cd – from the Lesser Poland Province. The differences between the regions in terms of the content of quantity elements and essential trace elements were statistically significant and showed much variety (with the exception of Cu). The analysis of correlation revealed positive and statistically important interactions between numerous elements, among which the most significant were observed in the pairs Na-K (rxy=0.77; p<0.01) and Cu-Mn (rxy=0.82; p<0.01). Only one negative and high statistically important relationship was noted – in the case of Cu and Zn (rxy= -0.71; p<0.01).

The main purpose of the study was to analyse the concentrations of selected essential and toxic trace elements in the hair of sports and recreational riding horses from studs located in central Poland and thus test the usefulness of this matrix for monitoring the exposure of these animals. We also measured the concentration of heavy metals in oats used as a basic component of the equine diet to investigate the interactions between these elements in the feed and hair. The basic chemical composition of oats was analysed. Elemental analysis was performed using an EcaFlow 150 GLP electrochemical analyser with an E-104L electrode and reference to a calibration curve. The chemical composition of oats was investigated by near infrared transmission (NIR) spectroscopy calibrated for an artificial neural network (ANN) using a Foss InfraXact spectrometer. Among all elements, the coefficient of variation was highest for Pb and lowest for Cd, regardless of the study group. The content of elements in horse hair was in the range of 153.56 to 185.79 mg·kg⁻¹ for Zn, 6.10 to 11.99 mg·kg⁻¹ for Cu, 0.578 to 0.813 mg·kg⁻¹ for Pb and 0.011 to 0.015 mg·kg⁻¹ for Cd (in kg of d.w.). For hair, we found a significant negative correlation for Zn-Cu (r_xy = −0.539) and Cd-Cu (r_xy = −0.676) at p ≤ 0.05. For feed, there was a highly significant positive correlation for Cu-Pb (r_xy = 0.723) and Zn-Cd (r_xy = 0.714) at p ≤ 0.01. We found significant negative oats–hair interactions for Cu-Zn, Pb-Cu, Cd-Cu and Zn-Pb, and a positive oats–hair interaction for Cu-Cu.