The present study was conducted to assess effects of selenium (Se)-yeast supplementation on glutathione peroxidase activity, Se levels in tissues, growth performance, carcass, and meat composition in broilers. A total of 275 one-d-old Cobb 500 broilers of both sexes were randomly allotted to 1 of 5 treatments during a 42-d period. The 5 treatments differed only in Se content: group 1 had no additional Se (background only); groups 2, 3, and 4 received 0.3 mg/kg of added Se from the beginning of the trial until d 21, whereas in the second half of the study (from d 22 to 42), these groups received 0.3, 0.6, and 0.9 mg/kg of added Se, respectively; and group 5 received 0.9 mg/kg of Se for the entire experimental period. At the end of the study, the control group showed significantly lower (P < 0.01) glutathione peroxidase activity in blood plasma compared to Se-supplemented groups. Regarding Se concentration in various tissues, the groups receiving Se yeast showed higher plasma, feces, and meat Se contents than the control group (P < 0.01). Supplementation of Se improved broilers' body weight, weight gain and feed conversion ratio (P < 0.01). Dressing percentage was lower in the control group and the group with 0.3 mg/kg of added Se compared to other experimental groups (0.6 and 0.9 mg/kg of dietary Se). The proportion of less valuable carcass parts (wings and legs) was higher (P < 0.01) in the group fed the basal diet compared to groups supplemented with 0.9 mg/kg of Se. Initial and ultimate pH values differed among experimental groups (P < 0.05). Supplementation of Se improved the broiler's antioxidative resistance, growth performance, carcass quality, and chemical composition of meat.

The aim of this study was to investigate the presence of heavy metals/metalloids (Pb, Cd, Hg, Cu, Fe, Zn, As) in the muscle tissue of fish from the Danube River (two locations: Zemun and Grocka). For the purpose of heavy metal determination in fish muscle, 120 samples of six different fish species, Prussian carp, barbel, bream, carp, pike perch, and catfish were collected. For determining heavy metals, we used microwave oven digestion and atomic absorption spectrometer methods. The highest average content of Pb (0.084 ± 0.004 mg kg), Cd (0.082 ± 0.003 mg kg), Hg (0.466 ± 0.006 mg kg), and As (0.333 ± 0.007 mg kg) was found in the muscle of carp (an omnivorous fish) from Grocka, while the highest average level of Fe (13.60 ± 0.03 mg kg) was deposited in bream (also omnivorous) from Zemun. Also, the average Cu level (1.62 ± 0.13 mg kg) was the highest in catfish muscle (a carnivorous fish) from Grocka, while the highest Zn content (11.16 ± 0.17 mg kg) was determined in muscle of Prussian carp (an omnivorous fish) from Zemun. The highest content of heavy metals (Cu, Fe, and Zn, respectively) in muscle of the six different types of fish from both locations was symmetrically arranged by species (catfish, barbel, and Prussian carp, respectively). Concentrations of Pb, Hg, and As in the Danube River fish muscle were under the maximum residual levels prescribed by the European Union (EU) and the maximum allowed concentrations (MAC) for Serbia. On the other hand, in all fish muscle from both locations (Zemun and Grocka), higher concentrations of Cd than prescribed (MAC) were found, with the exception of bream and pike perch.

Mycotoxins are chemical hazards of microbiological origin, produced mainly by filamentous fungi during their secondary metabolism. The role of mycotoxins has been recognized in the aetiology of a number of diseases, particularly cancers that belong to non-communicable diseases (NCDs). The NCDs have a leading and growing contribution to preventable deaths and disability across the globe. The NCDs are known as chronic diseases, tend to be of long duration and are the result of a combination of genetic, physiological, environmental and behavioural factors. Following the increased interest in health effects caused by synergisms between natural and synthetic contaminants along the food chain, mycotoxin contamination will continue to be an area of concern for producers, manufacturers, regulatory agencies, researchers and consumers in the future. Considering that their presence in food depends strongly on climatic conditions, in Serbia, recent drought and then flooding confirmed that mycotoxins are one of the foodborne hazards most susceptible to climate change. In this article, we review key aspects of mycotoxin contamination of the food supply chain and attempt to highlight the latest trends and projections for mycotoxin reduction from a Serbian perspective.

In order to investigate the effects of omega (n) 3 fatty acids on egg quality a group-control trial was organized. Trial lasted 40 days and was performed in production conditions. Total number of 1264 laying hens of Lohman Brown classic provenience were used and randomly allotted into one of four groups by 316 hens each (C-control, I experimental, II experimental and III experimental). All groups of hens were fed diets of standard ingredients and chemical composition, while feed of I, II and III experimental group of hens was supplemented with micro algae Schizochytrium spp. (DHA Gold?, Martek, USA) as a source of n- 3 fatty acids in amount of 0.5, 0.7 and 1.0 % respectively. In order to investigate the influence of micro algae Schizochytrium spp. feed supplementation on egg quality, from the aspect of content and ratio of fatty acids, random egg samples (n=10) were taken at the 10th, 20th and 40th day of the trial from each group. Egg yolk fatty acid content was determined by gas chromatography on Varian 1400 with flame ionization detector (FID detector) (on a packed column 20% LAC-3R-728 Chromosorb WAW 80-100 mesh). Significant differences in egg yolk fatty acid content as well as their ratio were determined between treatment groups. Positive influence of supplemented micro algae preparation was observed. Highest content of n-3 poly unsaturated fatty acids (PUFA n-3) was determined in egg yolks of III experimental group while lowest content was determined in egg yolks of control group of hens. Micro algae feed supplementation, at the end of the trial period, positively affected egg yolk PUFA n-6/PUFA n-3 ratio, since determined ratio of 4.24 in III experimental group was more desirable than 12.27 determined in a control group. Marine algae (Schizochytrium spp.) feed supplementation in laying hens in amounts above 0.5% significantly affected egg yolk fatty acid composition as well as ratio of n-6/n-3 PUFA. These findings support its use from nutritive, medical and economic point of view.

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