1,721,039 research outputs found
Influence of the larval rearing technique on morphological and productive traits of European sea bass (Dicentrarchus labrax L.).
No full textProve di ingrasso del gambero gigante d’acqua dolce (Macrobrachium rosenbergii, de Man) in stagno
No full textTwo small earth ponds (surface area 170 m2, depth 80 cm) on Lake Trasimeno (central Italy) were stocked at two different densities (2.8 and 7/m2) with juveniles of Macrobrachium rosenbergii weighing an average of 10.5 g. Water exchange was 60 1/sec/ha, and water temperature ranged from 17 to 28°C. The prawns received 5% of their live weight in pellets for catfish, twice daily for 120 days (June to October 1987). At the lower stocking density, survival rates of 91.2% and average final weights of 65.9 g were obtained; at the higher density, these rates were 87.3% and 49.1 g respectively
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
Quality traits and oxidative stability of chicken meat enriched with coniugated linoleic acid.
No full textEffect 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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Seasonal effects on some serum and muscle enzymes of catfish (Ictalurus melas) and common carp (Cyprinus carpio)
No full textEffects 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
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