No abstract

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 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.