1,721,058 research outputs found
Effect of feeding and genotype on the lipid profile of organic chicken meat.
No full textThe effects of partial substitution of soybean (SB) with faba bean (FB) and of genotypes [fast-growing Cobb 700 (FG), medium-growing naked-neck Kabir (MG), slow-growing Brown Classic Lohman (SG)] on the lipid composition as well as the meat quality attributes of chickens reared under organic conditions were evaluated. A total of 720 1-day-old male chicks were equally divided into three groups according to genotype and raised for 81 (MG and FG) or 96 days (SG): half birds of each genotype received either SB grower diet or FB grower diet. Meat from SG and MG birds exhibited a lower lipid content than that from FG birds. Both in breast and thigh meat, MUFA were significantly increased from SG to MG and FG. SG meat contained the highest amounts of either arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, or docosapentaenoic acid, but the lowest amounts of a-linolenic acid. Total PUFA gradually decreased from SG to MGand FG birds (413, 358, and 324 g/kg of fat), as well as total n-6 and total n-3. The D5- plus D6-desaturase index was 54.0, 34.4, and 23.6 for SG, MG, and FG birds, respectively. The n-6/n-3 ratio was lower in SG and MG than in FG birds. The partial replacement of SB with FB had a lesser effect than the genotype on the meat quality characteristics
The influence of low protein diets supplemented with isoleucine and valine on the quality and functional properties of chicken eggs
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Effects of Dietary Vitamin E on the Quality of Table Eggs Enriched with n-3 Long-Chain Fatty Acids
No full textBecause of the proposed cardioprotective benefits of n-3 fatty acids and vitamin E, a trial was carried out to investigate the possibility of enriching eggs with n-3 fatty acid and vitamin E added to the hen's diet. One hundred ninety-two Hy-Line Brown hens, 39-wk-old, were divided into eight groups: four groups received the basal diet supplemented with 3% lard and four doses of dl-α-tocopheryl acetate (0,50, 100, and 200 ppm), whereas the diets of the other groups were supplemented with 3% of fish oil and the same doses of vitamin E. The performances of the hens and egg weights were not affected either by the type of lipid supplement or by the vitamin level. The treatment with fish oil caused a dramatic increase (P < 0.01) of all n-3 fatty acids of the yolk, particularly EPA (19.53 vs. 0.74 mg/egg) and DHA (143.70 vs. 43.66 mg/egg), and an appreciable decrease of arachidonic acid (25.54 vs. 67.72 mg/egg). The different levels of dietary vitamin E slightly affected the fatty acid composition of the yolk. Yolk α-tocopherol increased linearly as dietary dl-α-tocopheryl acetate increased (P < 0.01) from the control level of 90.93 μg/g of yolk to 313.84 μg/ g of yolk when 200 ppm were added to the hen diets. Twenty-eight days of storage at room temperature (20 to 25 C) did not alter the yolk fatty acid profile, and, moreover, the levels of vitamin E remained still very close to those observed in fresh egg
Quality traits and oxidative stability of chicken meat enriched with coniugated linoleic acid.
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Sostenibilità delle produzioni avicunicole
No full textGli impatti ambientali delle produzioni animali rappresentano una delle principali preoccupazioni di cittadini, tecnici e decisori politici. Per poter affrontare il tema con competenza, è necessario approfondire le basi scientifiche del corretto calcolo degli effluenti delle filiere zootecniche e acquisire le tecniche disponibili per una loro mitigazione. Questo libro è il secondo testo di una serie di due volumi sulla sostenibilità ambientale delle produzioni zootecniche: il primo tratta i fondamenti della disciplina, con particolare riferimento all'ambito nazionale; il presente approfondisce i temi specifici delle filiere produttive bovina e bufalina, dei piccoli ruminanti, degli avicoli e cunicoli e dell'acquacoltura nonché degli allevamenti biologici e dei sistemi della mangimistica moderna. L'opera ha l'obiettivo di fornire un utile strumento per gli operatori delle filiere zootecniche e un manuale di base per i corsi di studio universitari e di specializzazione post-secondaria. La poderosa bibliografia riportata alla fine di ogni capitolo è un prezioso contributo alla diffusione degli elementi della letteratura scientifica mondiale all'interno di un dibattito troppo spesso caratterizzato da basi informative poco solid
Oxidative Stability And Quality Traits Of n-3 Pufa Enriched Chicken Meat
Full text linkA total of 360 broilers, female Cobb 500, were fed from 21 d to slaughter (46 d) a commercial diet supplemented with 0, 0.5 or 1% Schizochitrium sp. marine algae, as dietary source of n-3 PUFA. Meat with the highest n-3 PUFA content showed a reduced lipid stability, particularly in breast, while the organoleptic properties evaluated in drumsticks were not affected by the dietary treatment. Breast colour was deeper in the group receiving the highest algal supplementation
Variability and interaction of some egg physical and eggshell quality attributes during the entire laying hen cycle
Full text linkThe aim of this study was to investigate the variability and relationships between some egg physical (egg weight, width, length, shape index and surface area) and eggshell parameters (weight and percentage, thickness, breaking strength, L*, a*, and b* values) during the entire laying hen cycle. A total of 8,000 eggs was collected every 5 weeks, from 30 to 81 weeks of hens age (10 samplings of 400 eggs/house), in 2 identical poultry houses equipped with enriched cages. For the statistical analysis, ANOVA, Bivariate Correlation, Principal Component Analysis (PCA) and hierarchical cluster analysis were used. An increase of egg weight, length and eggshell lightness (L*) associated with a reduction of eggshell percentage, breaking strength, and redness (a*) was observed as the hen aged (P<0.05). Overall, the coefficients of variation resulted <5% in width, length, shape index, and egg surface area; from 5 to 10% of egg weight, shell weight, shell percentage, shell thickness, L*, and b*; >10% of eggshell breaking strength and a*. According to the PCA, the highest changes during the laying cycle are related to egg physical parameters (32%) and to eggshell breaking strength, percentage, and thickness (26%). The egg physical parameters appeared to be strongly correlated to each other, whereas a slight correlation between eggshell breaking strength and color attributes were evidenced (-0.231 and 0.289 respectively for L* and a*; P<0.01). Hierarchical cluster analysis, based on principal components of the overall egg attributes is hereby considered, evidenced dissimilarities for eggs laid from peak production up for 39 weeks of hen age from the eggs laid afterwards. The latter group could also be divided into two subgroups, one comprising eggs laid from 44 and 53 weeks of hen age and the other from 58 weeks to the end. In conclusion, the large dataset created in this study allowed to extrapolate some robust information regarding the variability and correlations of the egg physical and eggshell quality attributes throughout the entire laying hen cycle
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
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