الفهرس | Only 14 pages are availabe for public view |
Abstract An experiment was conducted to compare the effects of three organic selenium (Se) sources with four levels of supplementation on growth performance and carcass characteristics, selenium contents in feather, blood, liver, front and rear meat , GSH-PX activity, lipid peroxidase (TBA) and thyroid hormones of Japanese quail chicks. Three hundred and sixty (straight run) unsexed chicks of Japanese quail were individually wing-banded and placed in groups of ten chicks at seven days of age, for a 28-day experiment. In all experimental treatments, chicks were kept as possible under similar managerial and hygienic conditions. The experimental diets were supplemented with organic Se yeast and mixed with the common basal diets (at 0.1, 0.3 and 0.5 mg Se/kg of feed). Residual feeds were weighed back weekly, and weekly feed consumption was calculated. The experiment utilized a 3 x 4 x 3 factorially arranged completely randomized statistical design. Se was supplemented to the diets as the following design and the background levels of Se were analyzed in the tested diets. Each treatment was replicated three times. Each replicate consisted of ten chicks per replicate. The following results were obtained: Availa had heavier live body weight at 35days of age (LBW35), and higher estimates for either pooled daily gain or growth rate (PDG; PGR) and better feed conversion during the periods: 21-28, 28-35 and 7-35 days of age and had the highest performance index than other sources. Insignificant differences due to level of supplementation were found for LBW’s at all ages studied, PDG during all tested periods of growth. Availa 0.5 had the highest LBW35, daily gain during the periods 14-21 and 7-35 days of age, PGR during 21-28, 28-35 and 7-35 periods and had higher total revenue. As Se level increased, both the price/kg feed and feed cost increased. Either economic efficiency or relative economic efficiency (EEf or REEf) for 0.1 level insignificantly differed than the control and significantly differed than both 0.3 and 0.5. Availa 0.3 and 0.1 had significantly higher EEf (4.25 and 4.24 ) and REEf (107.06 and 104.00 than other source level groups. Neither source of organic Se nor level of supplementation and Source x Level significantly influenced each of individual absolute carcass parts, relative carcass parts(%) to live body weight and chemical composition traits. Results of this study revealed that the dietary Se supplied in an organic form as Availa with the levels of supplementation 0.1 and 0.3 can be used to improve Se status in Japanese quail which may led to greater resistance to oxidative stress and resulted in higher LBW35, Pooled gain7-35, EEf or REEf and performance index than other sources by levels without deteriorations in performance traits . This greater resistance to oxidative stress may improve meat quality. Key words: Organic selenium, levels, performance, glutathione peroxidase, T3, T4, T3/T4, TBA , Japanese quail. |