Interactions between lipid source and vitamin A on broiler performance, blood parameters, fat and protein deposition rate, and bone development.

A total of 2622 male broilers were distributed in a 2 × 5 factorial design, using 2 lipid sources (soybean oil and palm fat), 5 levels of vitamin A supplementation (0, 3,000, 6,000, 12,000, and 24,000 IU kg-1), with 10 replicates, and also 1 control diet (CD) for each lipid source used (7 replicates), each experimental unit being composed of 23 birds. During the first 21 d (how were the birds fed) and from 22 to 42 d of age, a redistribution of the treatments was carried out in a 2 × 2 × 5 factorial design: half of the repetitions of each treatment received the diet of the initial treatment, and the others received the CD with its type of lipid source. In the phase from 1 to 21 d of age, the effect of lipid source on feed intake (FI) and feed conversion ratio (FCR), and the effect of vitamin supplementation on FI and weight gain (WG) were observed, with a quadratic response for both variables. At 42 d of age, the lipid source and vitamin A level influenced the FI, whereas the WG and FCR showed interactions between period and the level of vitamin A supplementation. Neither lipid source resulted in blood parameters out of the typical pattern for birds, and the same was observed in relation to dietary vitamin A supplementation. From 1 to 21 d of age, a vitamin A supplementation of 15,585 IU kg-1 was estimated, and at 42 d, 15,527 IU kg-1 and 15,148 IU kg -1 were estimated for the periods 1 to 21 d and 1 to 42 d, respectively.

Energy values of crude glycerin for broilers / [Valores energéticos da glicerina bruta para frango de corte]

The energetic values of crude glycerin (CG) were determined for broilers at different ages using the method proposed by Matterson and by polynomial regressions. Two trials were performed with broilers from 11 to 21 and from 31 to 41 days of age. The birds were distributed in a completely randomized experimental design with a reference ration (RR), without CG, and three ration tests with replacement of 5%, 10%, and 15% of RR by CG. The metabolizable energy values were calculated by the Matterson method, and the apparent metabolizable energy (AME) values were used in polynomial regression analysis. The mean values of AME, apparent corrected for nitrogen balance (AMEn), metabolizable coefficient of gross energy (CAMEB), and corrected for nitrogen balance (CAMEBn) of CG, for the phase from 11 to 21 days by the Matterson method were 10.08 MJ kg-1, 10.04 MJ kg-1, 67.06%, and 66.74%, respectively. The inclusion of CG presented an increasing linear effect for CAMEB and CAMEBn in this period. From 31 to 41 days, these values were 10.38 MJ kg-1, 10.27 MJ kg-1, 69.02%, and 62.24%, respectively. The predicted AMEn value through the polynomial regression equations was 10.49 MJ kg-1 and 10.18 MJ kg-1, respectively. According to the equations proposed by Matterson, the crude glycerin EMAn values for broilers from 11 to 21 and 31 to 41 days of age were 10.04 MJ kg-1 and 10.26 MJ kg-1, respectively. According to Adeola's method the AMEn values were 10.49 and 10.20 MJ kg-1 for each phase.(AU)

Os valores energéticos da glicerina bruta (GB) foram determinados para frangos de corte em diferentes idades, por meio da utilização do método proposto por Matterson e de regressões polinomiais. Foram realizados dois ensaios: de 11 a 21 dias e de 31 a 41 dias de idade das aves; em ambos, as aves foram distribuídas em um delineamento experimental inteiramente ao acaso, com uma ração referência (RR), sem GB, e três rações testes com substituição de 5%, 10% e 15% da RR por GB. Foram calculados os valores de energia metabolizável pelo método de Matterson, sendo os valores de energia metabolizável aparente (EMA) utilizados na análise de regressão polinomial. Os valores médios da EMA corrigida pelo balanço de nitrogênio (EMAn), o coeficiente de metabolizabilidade da EB (CMAEB) e o corrigido para o balanço de nitrogênio (CMAEBn) da GB, na matéria natural, para a fase de 11 a 21 dias, pelo método de Matterson, foram de 10,08 MJ kg-1, 10,04 MJ kg-1, 67,06% e 66,74%, respectivamente. A inclusão de GB apresentou um efeito linear crescente para os CMAEB e os CMAEBn. Na fase de 31 a 41 dias, foram de 10,38 MJ kg-1, 10,27 MJ kg-1, 69,02% e 62,24%, respectivamente. Por meio das equações de regressões polinomiais, o valor de EMAn estimada foi de 10,49 MJ kg-1 e 10,18 MJ kg-1, respectivamente. Os valores de EMAn da GB para as idades 11 a 21 e 31 a 41 dias foram de 10,04 MJ kg-1 e 10,26 MJ kg-1, respectivamente. De acordo com as equações propostas por Matterson e com o método de Adeola, os valores de EMAn foram 10,49 e 10,20 MJ kg-1 para cada fase.(AU)

Valores energéticos e composição bromatológica do resíduo seco de fecularia associado a carboidrases para frangos de corte em fase de crescimento / [Energy value and bromatological composition of dry residue of cassava associated with carbohydrases for grower broilers]

Foram determinados os valores energéticos e a composição bromatológica do resíduo seco de fecularia (RSF) para frangos de corte, na fase de crescimento, utilizando ou não enzimas carboidrases. Os tratamentos foram distribuídos em esquema fatorial 2x4 + ração referência, sendo uma RR sem adição de RSF e quatro tratamentos experimentais com 10%, 20%, 30% e 40% de inclusão do RSF e a suplementação ou não com carboidrases. A composição química encontrada para o RSF, na MN, foi de 89,86% de matéria seca, 0,98% de proteína bruta, 3519kcal kg-1 de energia bruta, 0,19% de extrato etéreo, 27% de fibra em detergente neutro, 19,5% de fibra em detergente ácido, 0,33% de cálcio, 0,43% de fósforo, 0,46% de potássio e 0,12% de magnésio. O uso de carboidrases proporcionou um aumento de 173 e 213kcal kg-1 nos valores de EMA e EMAn, respectivamente, resultando em 1828kcal kg-1 EMA e 1840kcal kg-1 EMAn. Concluiu-se que os maiores níveis de EMA e EMAn foram encontrados para o nível de inclusão médio do RSF de 35% e que a suplementação enzimática pode promover aumento desses parâmetros em até 12% em dietas para frangos de corte na fase de crescimento.(AU)

The energetic values and the bromatological composition of the dry residue of cassava (DRC) were determined for growing broilers with or without carbohydrase enzymes. The treatments were distributed in a 2x4 + reference diet factorial scheme, with one RD without addition of DRC and four experimental treatments with 10, 20, 30 and 40% inclusion levels of RSF and supplementation or not with carbohydrases. The chemical composition found for DRC in natural matter was 89.86% dry matter, 0.98% crude protein, 3519kcal kg-1 gross energy, 0.19% ether extract, 27% neutral detergent fiber, 19.5% of acid detergent fiber, 0.33% of calcium, 0.43% of phosphorus, 0.46% of potassium and 0.12% of magnesium. The use of carbohydrase resulted in an increase of 173 and 213kcal kg-1 in EMA and EMAn values, respectively, resulting in 1828kcal kg-1 EMA and 1840kcal kg-1 EMAn. It was concluded that the highest levels of AME and AMEn were found for the mean inclusion level of the DRC of 35% and that enzymatic supplementation may promote the increase of these parameters by up to 12% in broiler diets in the growth phase.(AU)

Choosing sample sizes for various blood parameters of broiler chickens with normal and non-normal observations.

Experimental power is a measure of the ability of an experiment to detect differences between treatment means. Researchers design experiments and then calculate the probability that differences are simply due to chance, the null hypothesis. The objective of the analyses reported here was to determine the appropriate number of samples to demonstrate significant differences of various magnitudes from broiler chicken blood constituents. Over 800 samples were taken for a study of the effects of sample storage time, serum vs. plasma, light intensity, and fed vs. fasted birds on blood cholesterol, triglycerides, uric acid, glucose, total protein (TP), albumin, globulin, alanine aminotransferase (ALT), aspartate aminotransferase, gammaGT, creatinine, alkaline phosphatase, Ca and P. Various transformations increased the QQ plot R2 values from 0.000 to 0.149 or 0.00 to 17.62%. Most of the QQ plot R2 values were at or above 0.90. The 1/x2 transformation of blood P data showed the biggest increase in QQ plot R2 (0.846 to 0.995). The different standard deviations and coefficients of variation (CVs) found for each variable resulted in widely different numbers of replicates needed to detect differences in 2 treatment means. The extremes were glucose with a CV of 6.9% and ALT with a CV of 39.7%. For glucose, 15 replicates are needed to find a 10% difference in 97% of experiments; for ALT, 15 replicates would detect a 50% difference 91% of the time. The use of parameters such as cholesterol, glucose, TP, albumin, and globulin showed low CVs, indicating they may be considered as stable parameters. The lower CVs make it possible to find differences with a smaller number of replicates used in studies. As reported, the phosphorus values did not have a normal distribution of the data, so a transformation of these data could be an alternative to better discuss the results found.

Symmetry breaking: a heuristic approach to chaotic scattering in many dimensions.

As the theory of chaotic scattering in high-dimensional systems is poorly developed, it is very difficult to determine initial conditions for which interesting scattering events, such as long delay times, occur. We propose to use symmetry breaking as a way to gain the insight necessary to determine low-dimensional subspaces of initial conditions in which we can find such events easily. We study numerically the planar scattering off a disk moving on an elliptic Kepler orbit, as a simplified model of the elliptic restricted three-body problem. When the motion of the disk is circular, the system has an integral of motion, the Jacobi integral, which is no longer conserved for nonvanishing eccentricity. In the latter case, the system has an effective five-dimensional phase space and is therefore not amenable for study with the usual methods. Using the symmetric problem as a starting point we define an appropriate two-dimensional subspace of initial conditions by fixing some coordinates. This subspace proves to be useful to define scattering experiments where the rich and nontrivial dynamics of the problem is illustrated. We consider in particular trajectories which take very long before escaping or are trapped by consecutive collisions with the disk.