Abstract. The aim of the present work was to determine the fatty acid profiles, total cholesterol content, and the fat percentage in the meat of the abdominal section of spiny-cheek crayfish, Orconectes limosus (Raf.), caught in Lake Gop³o. A total of 177 males (aged 3+ and 4+) were collected in spring and summer for the analyses. The meat of crayfish caught during spring had higher fat contents (1.09 % in 3+ individuals and 1.10 % in older crayfish) than that in individuals from summer at 0.92 and 1.05%, respectively. Differences among these means were not statistically significant (P > 0.05). The total cholesterol content was higher in the meat of crayfish caught in summer (71.98 mg 100 g -1 ),and these values differed significantly from those obtained from individuals in spring (65.32 mg 100 g -1 ). In all groups of crayfish analyzed, the main SFA was C16:0, MUFAs were dominated by C18:1 n-6, and the highest percentage of PUFAs was of C20:5 n-3.

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breeding region and season on the content of some trace elements and heavy metals in the hair of cows. Folia Biologica (Kraków) 62: 163-169. The aim of the research was to determine the effect of the season and the breeding region on the content of selected minerals (Zn, Cu, Mn, Fe, Pb, Cd) in the hair of dairy cows. The research material covered 114 Holstein-Friesian breed cows from three breeding centres in Poland, hereafter referred to as A, B and C. Breeding centre A is located in Opolskie province, breeding centre B in Podlaskie province and breeding centre C in Kujawsko-Pomorskie province.The cows were kept in freestanding cowsheds with den boxes. Animal nutrition involved the use of the TMR system, considering division into nutrition groups. Hair was sampled in summer and in the period of winter and spring from the side of the body, directly behind the coastal arch. The Zn, Cu, Mn, Fe analysis was performed with atomic absorption spectrometry. The Pb and Cd content was assayed with the use of the electrothermal atomic absorption spectrometry. The results demonstrated the effect of season and breeding region on the level of the minerals and heavy metals assayed in the hair of cows being in the period of drying-off. The hair sampled in winter from cows from C demonstrated a higher concentration of most elements except for Fe than in material derived in summer. Hair

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.