1,720,958 research outputs found
Vitamin E supply of different matrices for laying hens
No full textThe study in laying hens investigated the bioavailability of three different vitamin E sources, engaged by different matrix and different level of supplementation. Zootechnical parameters, storage in egg yolk and liver tissue, digestibility parameters and carry over effects were examined. Experiments were conducted with 42 laying hens in seven groups with six animals per group in a two-factorial design: (M = factor "matrix", C = factor "concentration"). Factor matrix included: (M(1)) Vitamin E (50% d,1-alpha-tocopher-yl-acetate), inorganic matrix (50% Silicon dioxide), (M(2)) vitamin E (25% micro encapsulated d,l-a-tocopheryl-acetate in fractionated palm fats), palm fat based matrix, (M(3)) vitamin E (50% d,1-alpha-tocopheryl-acetate), starch based matrix (main constituents modified starch and gum Arabic). Factor concentration contained: (C(1).) Vitamin E only from native ingredients of the basal diet, (C(2)) + 5 mg vitamin E/kg mixed feed and (C(3)) + 30 mg vitamin E/kg mixed feed. The study run for 16 weeks, feed without added vitamin E (depletion feed) was supplied in weeks 1-2 and 5-9, respectively. Over the experimental period, no significant effect of the factors "preparation" and "concentration" on live weight, feed intake, laying percentage and daily egg mass production was obtained. Vitamin E enrichment of the egg yolk and vitamin E transfer responded significantly to the factor "concentration". Due to the factor "preparation", significant effects were not observed. Vitamin E storage in the liver depended significantly on the factor "concentration". Factor "preparation" responded dependent on level of supplementation. At low supplementation, the effect on vitamin E concentration in the liver and carry over factor was more pronounced by preparation "starch", at higher level of supplementation superior effects were stated for the preparation "fat". Observed disappearance of vitamin E from the gut was independent on preparation, but dependent on the factor "concentration". In conclusion, each of the added vitamin E sources under study was highly available for the laying hen. Significant advantages of one of the vitamin E sources were not observed. These conclusions are restricted to laying hens and cannot be generalized for other species.Berg + Schmidt GmbH & CO Hamburg/German
Vitamin E supply of different matrices for laying hens
No full textThe study in laying hens investigated the bioavailability of three different vitamin E sources, engaged by different matrix and different level of supplementation. Zootechnical parameters, storage in egg yolk and liver tissue, digestibility parameters and carry over effects were examined. Experiments were conducted with 42 laying hens in seven groups with six animals per group in a two-factorial design: (M = factor "matrix", C = factor "concentration"). Factor matrix included: (M(1)) Vitamin E (50% d,1-alpha-tocopher-yl-acetate), inorganic matrix (50% Silicon dioxide), (M(2)) vitamin E (25% micro encapsulated d,l-a-tocopheryl-acetate in fractionated palm fats), palm fat based matrix, (M(3)) vitamin E (50% d,1-alpha-tocopheryl-acetate), starch based matrix (main constituents modified starch and gum Arabic). Factor concentration contained: (C(1).) Vitamin E only from native ingredients of the basal diet, (C(2)) + 5 mg vitamin E/kg mixed feed and (C(3)) + 30 mg vitamin E/kg mixed feed. The study run for 16 weeks, feed without added vitamin E (depletion feed) was supplied in weeks 1-2 and 5-9, respectively. Over the experimental period, no significant effect of the factors "preparation" and "concentration" on live weight, feed intake, laying percentage and daily egg mass production was obtained. Vitamin E enrichment of the egg yolk and vitamin E transfer responded significantly to the factor "concentration". Due to the factor "preparation", significant effects were not observed. Vitamin E storage in the liver depended significantly on the factor "concentration". Factor "preparation" responded dependent on level of supplementation. At low supplementation, the effect on vitamin E concentration in the liver and carry over factor was more pronounced by preparation "starch", at higher level of supplementation superior effects were stated for the preparation "fat". Observed disappearance of vitamin E from the gut was independent on preparation, but dependent on the factor "concentration". In conclusion, each of the added vitamin E sources under study was highly available for the laying hen. Significant advantages of one of the vitamin E sources were not observed. These conclusions are restricted to laying hens and cannot be generalized for other species.Berg + Schmidt GmbH & CO Hamburg/German
Assessment of nitrogen maintenance requirement and potential for protein deposition in juvenile Tilapia genotypes by application of an exponential nitrogen utilization model
No full textAssessment of quantitative amino acid requirement data in fish nutrition is predominantly based on dose response studies with supplementation of the dietary limiting amino acid. Studies with modeling amino acid requirements are scarce. Three experiments were conducted with different genotypes of juvenile Tilapia [A: all male . niloticus; B: red Tilpia (O. mossambicus x O. hornorum); C: hybrid Tilapia. (A x B)] using fishmeal-wheat gluten diets with five graded levels of dietary protein supply (17.2-48.5% CP). The dietary amino acid ratio was similar, dietary energy contents were adapted to avoid limiting energy supply. Growth response was studied in a semi-closed in-door water recirculation system with 38 tanks (3201/tank; water temperature 28 +/- 0.5 degrees C regulated photoperiod 12 h light/12 h dark). Four replicate groups (25 fish per tank) were utilized in a 70 d growth experiment with three times a day feeding until apparent satiation. Ten fish at the beginning and three fish per tank at the end of the growth study were analyzed for body composition to calculate N-deposition and N-excretion. The nitrogen maintenance requirement (NMR) was established based on nonlinear fitting of N-excretion depending on N-intake. The intersection of the applied exponential function with they-axis was used as NMR, simulating protein free feeding. The theoretical potential for daily N-deposition of the genotypes under study (NDmaxT) was estimated as threshold value due to exponential fitting of N-deposition depending on N-intake. The observed average NMR (70 mg N/B-kg(0.67)/d) and threshold values for genotype A (NDmaxT=388 mg/BWkg0.67/d), genotype B (NDmaxT=389 mg/BWkg0.67/d) and genotype C (NDmaxT=319(kg)(0.67)/d), respectively, are the starting point for the studied exponential N-utilization model and its subsequent application for assessing amino acid requirements depending on growth performance and dietary amino acid efficiency in fish feed. (c) 2006 Elsevier B.V. All rights reserved
Microbial Phytase and Nutrient Utilization in Low Phosphorus Chicken Diets
No full textExperiments were conducted with male growing chicken (Cobb 500) to examine effects of added microbial phytase on growth performance and nutrient utilization in corn-soybean meal (CSM) and wheat-soybean meal (WSM) diets. Low P basal diets (CSM1: 0.15 / 0.11% NPP in DM of starter/grower diets; WSM1: 0.16/0.12% NPP in DM of starter/grower diets) were supplemented with 250 or 500U/kg of an experimental microbial phytase (CSM2, CSM3; WSM2, WSM3) or 1.5g/kg inorganic phosphorus (CSM4, WSM4). Growth studies were conducted (7-42d) to establish nutrient deposition (6 pens per diet, 10 birds per pen). Separate balance studies (n=8) yielded individual N and P balance data for the age period 21-25d. Additionally, studies with CSM diets also provided tibia composition data.Phytase supplementation in CSM diets yielded significant effects on growth and deposition data. Additionally, the mortality rate declined significantly and tibia composition (ash, P, Ca) was improved. WSM diets provided more pronounced effects on deposition data, but growth responded only numerical. Balance studies delivered significant effects on P utilization due to phytase addition in both CSM and WSM diets, respectively. However, lower P utilization was observed in CSM diets. Significant effects of phytase addition on N utilization were established only in CSM diets. Consequently, generalized conclusions due to improved N utilization following phytase addition are not supported by the current study
Evaluation of dried distillers' grains with solubles (DDGS) as a protein source for broilers
No full textMale broiler chicks (n = 120) were fed diets containing 0, 5, 10 or 15% dried distillers' grains with solubles (DDGS) from the 12th day up to the end of fattening (day 35). During this period feed intake, weight gain and excreta quality (pH, DM) were tested. A digestibility trial was carried out on four birds from each group on the last five days of the experiment to determine the digestibility of organic matter and CP of the different diets. The protein digestibility was evaluated using three different methods; uric acid correction, alpha-amino-N and amino acid-N. There were no significant effects of increased DDGS levels on feed intake, weight gain, excreta quality or digestibility of CP and organic matter. However, feed conversion showed a tendency to decline at the highest DDGS level (15%). Digestibility of DDGS protein was estimated to be 77%. There was no significant difference between uric acid and alpha-amino-N method, but both methods had a significantly lower CP digestibility than amino acid-N. The present results indicate that DDGS can be used as a protein source in diets for fattening broilers up to 10-15%
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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