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.

Poultry meat production has doubled in past 40 years in the world, with the tendency of constant growth, and its production volume exceeds beef, but is behind pork production. For poultry meat production it is typical that its annual increase exceeds pork as well as beef production. The biggest producers of poultry meat are Asia, North and South America and Europe. The most significant category of poultry is meat of young chicken (broilers). Cobb, Ross and Hubbard broiler provenance are most common in Serbia. The objective of this investigation was to analyse poultry meat production volume in Serbia, observed during three six-years periods - A (1984-1989), B (1994-1999) i C (2004-2009). For data processing there were used the data obtained from Statistical Yearbooks of Serbia from 1984. to 2009. It was found out that average poultry meat production in period A was 108,33 ± 7,00 thousand tonnes, than it statistically significantly decreased and in period B it was 76,67±5,54 thousand tonnes, and finally in period C it was 72,17± 5,78 thousand tonnes. [Projekat Ministarstva nauke Republike Srbije, br. TR 31034

Objašnjenje skraćenih oznaka koje su korišćene u radu GPx enzim glutation peroksidaza MDA malondialdehid TBK tiobarbiturna kiselina P/S odnos polinezasićenih i zasićenih masnih kiselina S A D R Ž A J 1. UVOD 2. PREGLED LITERATURE 2.1. Fizičke i hemijske osobine selena 2.1.1. Rasprostranjenost selena u prirodi 2.1.1.1. Rasprostranjenost selena u mineralnim naslagama 2.1.1.2. Rasprostranjenost selena u zemljištu 2.1.1.3. Rasprostranjenost selena u biljkama 2.2. Resorpcija i metabolizam selena kod životinja 2.3. Biološka raspoloživost selena 2.4. Potrebe životinja u selenu 2.5. Bolesti ljudi i životinja povezane sa nedovoljnim unosom selena 2.6. Selen u ishrani ljudi i životinja 2.6.1. Uloga i značaj selena 2.6.2. Selen u hranivima biljnog porekla 2.6.3. Selen u namirnicama animalnog porekla 2.7. Izvori selena 2.8. Nedostatak i smanjeno unošenje selena 2.9. Proizvodni rezultati 2.9.1. Uticaj dodavanja selena na proizvodne rezultate 2.10. Klanične osobine 2.10.1. Uticaj dodavanja selena na klanične osobine 2.11. Osobine mesa 2.11.1. Uticaj dodavanja selena na osobine mesa 2.12. Funkcionalna hrana 2.12.1. Povećane količine selena u hrani animalnog porekla 3. CILJEVI I ZADACI RADA 4. MATERIJAL I METODE RADA 4.1. Materijal 4.1.1. Izbor materijala 4.1.2. Držanje i hranjenje brojlera 4.1.3. Formiranje ogleda 4.1.4. Ishrana brojlera 4.1.

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