RESUMO
The present study aimed to determine the ideal sodium levels for muscovy ducks in housing. Two hundred and forty muscovy ducks of creole lineage were used, distributed in boxes with water and food ad libitum. The experimental design was completely randomized, where treatments were constituted by six nutritional plans (initial, growth and termination) with different sodium levels, and four replicates of 10 muscovy ducks each. The birds had weekly performance evaluations, and after 90 days, eight birds (four males and four females) in each treatment were slaughtered for evaluation of carcass traits. Data collected were subjected to Tukey test at 5% of significance. Differences were observed (p 0.05) in performance (feed intake and feed conversion), where average levels of sodium presented better results. In carcass yields, average levels presented a positive influence (p 0.05) on muscovy duck growth. Male muscovy ducks presented better feed efficiency than females in the same period. The present study indicates that nutritional plan 3 (initial = 0.25%; growth = 0.30% and termination = 0.35%) showed better nutritional requirements of sodium for muscovy ducks in housing, obtaining better performance and carcass development.(AU)
Assuntos
Animais , Patos/metabolismo , Patos/fisiologia , Necessidades Nutricionais , SódioRESUMO
The present study aimed to determine the ideal sodium levels for muscovy ducks in housing. Two hundred and forty muscovy ducks of creole lineage were used, distributed in boxes with water and food ad libitum. The experimental design was completely randomized, where treatments were constituted by six nutritional plans (initial, growth and termination) with different sodium levels, and four replicates of 10 muscovy ducks each. The birds had weekly performance evaluations, and after 90 days, eight birds (four males and four females) in each treatment were slaughtered for evaluation of carcass traits. Data collected were subjected to Tukey test at 5% of significance. Differences were observed (p 0.05) in performance (feed intake and feed conversion), where average levels of sodium presented better results. In carcass yields, average levels presented a positive influence (p 0.05) on muscovy duck growth. Male muscovy ducks presented better feed efficiency than females in the same period. The present study indicates that nutritional plan 3 (initial = 0.25%; growth = 0.30% and termination = 0.35%) showed better nutritional requirements of sodium for muscovy ducks in housing, obtaining better performance and carcass development.
Assuntos
Animais , Necessidades Nutricionais , Patos/fisiologia , Patos/metabolismo , SódioRESUMO
Two indigenous ceramics fragments, one from Lagoa Queimada (LQ) and another from Barra dos Negros (BN), both sites located on Bahia state (Brazil), were dated by thermoluminescence (TL) method. Each fragment was physically prepared and divided into two fractions, one was used for TL measurement and the other for annual dose determination. The TL fraction was chemically treated, divided in sub samples and irradiated with several doses. The plot extrapolation from TL intensities as function of radiation dose enabled the determination of the accumulated dose (D(ac)), 3.99 Gy and 1.88 Gy for LQ and BN, respectively. The annual dose was obtained through the uranium, thorium and potassium determination by ICP-MS. The annual doses (D(an)) obtained were 2.86 and 2.26 mGy/year. The estimated ages were approximately 1375 and 709 y for BN and LQ ceramics, respectively. The ages agreed with the archaeologists' estimation for the Aratu and Tupi tradition periods, respectively.
Assuntos
Arqueologia/métodos , Cerâmica/história , Medições Luminescentes/métodos , Brasil , História Antiga , Luminescência , Fatores de TempoRESUMO
Ancient potteries usually are made of the local clay material, which contains relatively high concentration of iron. The powdered samples are usually quite black, due to magnetite, and, although they can be used for thermoluminescene (TL) dating, it is easiest to obtain better TL reading when clearest natural or pre-treated sample is used. For electron paramagnetic resonance (EPR) measurements, the huge signal due to iron spin-spin interaction, promotes an intense interference overlapping any other signal in this range. Sample dating is obtained by dividing the radiation dose, determined by the concentration of paramagnetic species generated by irradiation, by the natural dose so as a consequence, EPR dating cannot be used, since iron signal do not depend on radiation dose. In some cases, the density separation method using hydrated solution of sodium polytungstate [Na6(H2W12O40).H2O] becomes useful. However, the sodium polytungstate is very expensive in Brazil; hence an alternative method for eliminating this interference is proposed. A chemical process to eliminate about 90% of magnetite was developed. A sample of powdered ancient pottery was treated in a mixture (3:1:1) of HCl, HNO(3) and H(2)O(2) for 4h. After that, it was washed several times in distilled water to remove all acid matrixes. The original black sample becomes somewhat clearer. The resulting material was analyzed by plasma mass spectrometry (ICP-MS), with the result that the iron content is reduced by a factor of about 9. In EPR measurements a non-treated natural ceramic sample shows a broad spin-spin interaction signal, the chemically treated sample presents a narrow signal in g=2.00 region, possibly due to a radical of (SiO(3))(3-), mixed with signal of remaining iron [M. Ikeya, New Applications of Electron Spin Resonance, World Scientific, Singapore, 1993, p. 285]. This signal increases in intensity under gamma-irradiation. However, still due to iron influence, the additive method yielded too old age-value. Since annealing at 300 degrees C, Toyoda and Ikeya [S. Toyoda, M. Ikeya, Geochem. J. 25 (1991) 427-445] states that E1'-signal with maximum intensity is obtained, while annealing at 400 degrees C E1'-signal is completely eliminated, the subtraction of the second one from 300 degrees C heat-treated sample isolate E1'-like signal. Since this is radiation dose-dependent, we show that now EPR dating becomes possible.