77 research outputs found
Effect of corn particle size and inclusion of organic acid in the diet on growth performance and gastrointestinal structure in young chicks.
The effect of 3 corn particle sizes (dgw: 375, 1117, and 2402 μm) combined with or without organic acids (0.3 g/kg of Galliacid S®) was investigated on broilers from day 1 to day 21; 540 1-day old Ross 708 males were raised in 36 pens (3x2 factorial design, 6 blocks each). We measured: body weight, feed intake, feed conversion ratio, liver weight, pH weight and height of empty gizzard, pH and length of intestine and caeca, height and width of ileal villi, crypt depth/gland diameter, total bacteria count. Different corn particle sizes and organic acid supplements only affected feed intake (days 14 and 21), feed conversion ratio (day 14), villus height, and crypt depth. On day 21, fine milling had negative effects on body weights compared with larger feed particle size (816 vs 848 and 844 g); acidic additive had a positive effect on broiler growth (859 vs 813g). Length of small intestinal villi and crypt depth were affected by both particle size and organic acids (fine to coarse small intestinal villi: 1869a, 1401c, and 1039d μm in non-acidified; 1708b, 1535c, and 942e μm in acidified. Fine to coarse crypt depth: 102ab, 98b; 65c μm in non-acidified; 106a, 70c, and 66c μm in acidified). No difference was observed in total bacteria counts of the gut in relation to the different treatments. Use of organic acids during starter phase is useful, especially when the milling process is inappropriate
Effect of hydrolysed fish protein and autolysed yeast as alternative nitrogen sources on gilthead sea bream (Sparus aurata) growth performances and gut morphology
The aim of the present study was to compare the effects of two different nitrogen-rich ingredients such as hydrolysed fish protein and autolysed yeast, on gilthead sea bream (Sparus aurata) growth performances and histological gut morphology. Animals were allocated to three experimental groups: the first received a fishmeal-based diet (FM), the second and the third received hydrolysed fish protein (HFP) and autolysed yeast (AY), respectively, to replace an equal amount of fishmeal. The experiment lasted 92 days. No significant differences in body weight and mortality were observed among the different groups. Villus branching, intraepithelial lymphocytes and inflammatory infiltrate of the submucosa were more prominent in AY than HFP and FM. The gut absorbent surface ratio was 5.94, 6.44 and 7.28 for group FM, HFP and AY, respectively, with statistical significant difference between FM and AY and between HFP and AY. A significant increment in the goblet cell density was observed for HFP and AY in comparison to FM. A statistically significant increase in small-sized goblet cells was observed in AY compared to FM. All our findings suggest that it is possible to use either HFP or AY, as partial replacer of FM in the S. aurata diet.Highlights Yeast-derived products as a suitable alternative nitrogen source. Autolyzed yeast as a novel approach in the use of yeast products. Use of autolysed yeast for replacing fishmeal in aqua feed. Use of hydrolysed fish protein for replacing fishmeal in aqua feed
Effect of oral administration of 1,3-1,6 β-glucans in DWV naturally infected newly emerged bees (apis mellifera L.)
Honeybee pathogens have an important role in honeybee colony mortality and colony losses; most of them are widely spread and necessitate worldwide solutions to contrast honeybee's decline. Possible accepted solutions to cope with the spread of honeybee's pathogens are focused on the study of experimental protocols to enhance the insect's immune defenses. Honeybee's artificial diet capable to stimulate the immune system is a promising field of investigation as ascertained by the introduction of 1,3-1,6 β-glucans as a dietary supplement. In this work, by collecting faecal samples of honeybees exposed to different dietary conditions of 1,3-1,6 β-glucans (0.5% and 2% w/w), it has been possible to investigate the Deformed wing virus (DWV) viral load kinetic without harming the insects. Virological data obtained by a one-step TaqMan RT-PCR highlighted the ability of 1,3-1,6 β-glucans to reduce the viral load at the 24th day of rearing. The results indicated that the diet supplemented with 1,3-1,6 β-glucans was associated with a dose-dependent activation of phenoloxidase. The control group showed a higher survival rate than the experimental groups. This research confirmed 1,3-1,6 β-glucans as molecules able to modulate honeybees' defense pathways, and this is the first report in which the kinetic of DWV infection in honeybee faeces has been monitored by a RT-qPCR
Quantification and characterization of the environmental impact of sea bream and sea bass production in Italy
While the production of fish from aquaculture has grown steadily over the years worldwide, some environmental
concerns have emerged. In this study, the environmental impacts and main hotspots of a typical Italian sea bass
and sea bream offshore farm were analysed. The Life Cycle Assessment (LCA) methodology was applied with a
“cradle to farm gate” perspective and 1 ton of fish at harvest size as the functional unit. The results confirm that
feed is the main hotspot and contributes across impact categories always at least 60%, with the exception of
marine eutrophication driven instead by nutrient emissions. In some impact categories, infrastructure and farm
operations also have a relevant impact (about 30%). The impacts of this case study are slightly lower than those
found in the literature, and this is mainly due to prior attention of the company to feed formulation. An alternative
scenario was also explored, by reducing the amount of uningested feed, showing a reduction in the Global
Warming Potential by 6% and in marine eutrophication by up to 10%. The application and evaluation of new
technologies (e.g., automated feed dispenser, use of alternative cage materials) could be explored in future
research
The effect of Aspergillus niger as a dietary supplement on blood parameters, intestinal morphology, and gut microflora in Haidong chicks reared in a high altitude environment
Aim: The effects of the inclusion of Aspergillus niger in the diet of Haidong chicks reared in the Qing-Zang high altitude area (China) under hypoxic conditions. Materials and Methods: A total of 720 Haidong chicks were randomly divided into six groups and fed diets supplemented with 0%, 0.5%, 0.75%, 1.0%, 1.25%, and 1.5% of A. niger to determine blood parameters, intestinal morphology, and gut microflora in Haidong chicks reared in a high altitude environment. Results: Packed cell volume (PCV), red blood cell (RBC) count, white blood cell count, and hemoglobin concentration increased in the groups fed diets containing A. niger. The administration of A. niger in 1.0% and 1.25% significantly decreased the concentration of Escherichia coli in the cecum, while the concentration of Bifidobacterium and Lactobacillus in the cecum and ileum was increased in the treated groups. When compared to the control groups, villi height, crypt depth, and goblet cell density in the intestine was raised, in general, in the groups treated with A. niger. Conclusion: These findings suggest that 1.25% A. niger as dietary supplement may improve the resistance to ascites among birds reared under hypoxic conditions
Effect of honey and syrup diets enriched with 1,3-1,6 β-glucans on honeybee survival rate and phenoloxidase activity (Apis mellifera l. 1758)
β-glucans can activate the animal innate immune system by acting as immune-modulators and inducing various stimulatory effects. The aim of this study was to investigate the effect of 1,3-1,6 β-glucans administered orally for 96 h on Apis mellifera workers (newly emerged and nurse bees). β-glucans were included in honey and syrup. Survival rate and phenoloxidase activity were measured. In both newly emerged and nurse bees, β-glucans supplementation did not affect survival rate (p > 0.05). Conversely, phenoloxidase activity was higher in both newly emerged bees (p = 0.048) and nurse bees (p = 0.014) fed with a honey diet enriched with β-glucans compared to those fed with only honey. In both the newly emerged and nurse bees, no statistical differences in phenoloxidase activity were recorded between the group fed with a syrup-based diet enriched with β-glucans and the control group (p > 0.05). The absence of significant variation in survival suggests that the potential negative effect of β-glucans in healthy bees could be mitigated by their metabolism. Conversely, the inclusion of β-glucans in a honey-based diet determined an increase of phenoloxidase activity, suggesting that the effect of β-glucan inclusion in the diet of healthy bees on phenoloxidase activity could be linked to the type of base-diet. Further investigations on β-glucans metabolism in bees, on molecular mechanism of phenoloxidase activation by 1,3-1,6 β-glucans, and relative thresholds are desirable. Moreover, investigation on the combined action of honey and β-glucans on phenoloxidase activity are needed
Multi-Criteria DEXi Analysis for the Selection of Crop Species for Saltwater Aquaponics
Saltwater aquaponics is a sustainable alternative system for food production. The success of this system largely depends on the selection of both fish and plant species, for which several features and criteria must be considered. This paper aims to identify the most suitable plant species for saltwater aquaponics by using a multi-criteria decision-making method also based on current literature. One simple model that contained one root criterion, four aggregated criteria, and four sub-criteria was created using DEXi software. The same model was evaluated considering two different salinity levels in the recirculating water: 10 (brackish water) and 35 (sea water) g L-1. The relevance of the model structure was evaluated by the sensitivity analysis, through the 'plus/minus-1 ' analysis. Our results suggest that Salicornia europaea L. and Portulaca oleracea L. were suitable species for saltwater aquaponics at 35 g L-1. Moreover, at 10 g L-1, the suitable candidates were: Salicornia bigelovii Torr, S. europaea L., Beta vulgaris ssp. maritima (L.) Arcang, Atriplex hortensis L., and P. oleracea L. The DEXi analysis resulted in being an easy and effective tool to select proper species in similar contexts. DEXi can help to identify the hotspots of production processes, according to our results. Since the selected species are wild edible species or minor crops, the availability of their seeds is one of the main constraints of their cultivation in saltwater aquaponics
Fishmeal replacement with hermetia illucens meal in aquafeeds: Effects on zebrafish growth performances, intestinal morphometry, and enzymology
Fishmeal (FM) is still the most important protein source in aquafeeds. However, due to the reduction of wild fish stocks used for FM production, its manufacturing it is now unsustainable. Insect meal represents a valid alternative to FM, due to the low carbon footprint of its production and its high nutritional value. The aim of this study was to investigate the potentials of replacing FM with black soldier fly (Hermetia illucens) meal (HIM) in aquafeeds, using zebrafish as the animal model. Four diets were formulated with increasing HIM/FM replacement rate (the control diet contained 20% FM). Mortality rates, growth performances, and feed consumptions were measured, and fish intestine samples were collected for histological and enzymatic analysis. After 49 days, all groups almost tripled their initial body weight (cumulative body weight gain ranged between 143.9 and 155.2 mg), and no statistically significant differences among treatments were observed in relation to growth performances and histological traits. Contrarily, trypsin, alkaline phosphatases, and alpha amylase–glucoamylase activities were significantly reduced when the FM replacement rate was increased. In conclusion, HIM may represent an alternative to FM, since no adverse effects were observed when it was included up to 20% in the zebrafish diet, even when replacing 100% of the FM
A catalog of new Blazar candidates with Open Universe by High School students
Blazars are active galactic nuclei whose ultra-relativistic jets are
coaligned with the observer direction. They emit throughout the whole e.m.
spectrum, from radio waves to VHE gamma rays. Not all blazars are discovered.
In this work, we propose a catalog of 54 new candidates based on the
association of HE gamma ray emission and radio, X-ray an optical signatures.
The relevance of this work is also that it was performed by four high school
students from the Liceo Scientifico Statale Ugo Morin in Venice, Italy using
the open-source platform Open Universe, in collaboration with the University of
Padova. The framework of the activity is the Italian MIUR PCTO programme. The
success of this citizen-science experience and results are hereafter reported
and discussed.Comment: Proceedings of the 12th Cosmic Ray International Symposium (CRIS
2022), 12-16 September 2022, Naples (Italy). Send correspondence to:
[email protected], [email protected]
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