Spanish Journal of Agricultural Research
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Effect of dietary vegetable lipid sources on the growth performance and whole-body fatty acid profile of giant trahira, Hoplias lacerdae
No full textAim of study: To evaluate which vegetable lipid source promotes better growth performance, whole-body composition and fatty acid profile for juvenile giant trahira (Hoplias lacerdae).
Area of study: Fish Nutrition Laboratory of the University of Viçosa (UFV), MG, Brazil.
Material and methods: A 50-day feed trial with four treatments, consisting of diets containing different vegetable lipid sources (canola, linseed, soybean or olive oil), was conducted with juveniles of 4.76 ± 0.50 cm and 1.97 ± 0.20 g.
Main results: There were no effects of vegetable lipid sources on growth performance. Fish fed diets containing canola oil had higher body lipid deposition and fish fed with linseed oil had lower body lipid content (up to -19.29%) than fish from other treatments. Fish fed canola oil showed lower proportions of saturated fatty acids (up to -11.27%) in the body. Fish fed diets containing soybean oil and linseed oil showed the highest percentages of linoleic and α-linolenic fatty acids, respectively. Fish fed diets containing soybean and linseed oils also had higher total polyunsaturated fatty acids content (up to +81.14%). Fish fed diets containing linseed oil had lower content of monounsaturated fatty acids (up to -58.59%) and higher content of docosahexaenoic (up to +175%) and eicosapentaenoic (not detectable to detectable) acids.
Research highlights: Juveniles of giant thraira can alter the whole-body fatty acid profile due to their ability to desaturate and elongate the n3 and n6 series fatty acids. Linseed oil was identified as lipid source for this fish species
Short communication: Sodium chloride levels in pacu (Piaractus mesopotamicus) fingerling feeds free of fish meal
No full textAim of study: To evaluate the effects of increasing NaCl levels on the zootechnical performance of pacu fingerling.
Area of study: The experiments were conducted at the Aquatic Organism Production and Reproduction Systems Laboratory belonging to the Federal University of Paraná (UFPR), in the Palotina Sector, Paraná Estate, Brazil.
Material and methods: Seven hundred and fifty fingerlings with an average weight of 3.41 ± 0.09 g were distributed in circular boxes, in a completely randomized design consisting of six treatments and five replications. Treatments comprised soybean- and maize-based diets containing increasing levels of NaCl (0.00, 0.25, 0.50, 0.75, 1.00 and 1.25%). The experiments were conducted for 50 days. At the end of the experimental period the fish were fasted for 24 hours, anesthetized, weighed and measured to calculate zootechnical performances. Performance data were subjected to an analysis of variance followed by Tukey’s test when significant differences were found between the means (p<0.05).
Main results: The influence (p<0.05) of dietary NaCl levels on final weight, feed intake, apparent feed conversion, specific growth rate, average weight gain, clean trunk production, head carcass yield, headless carcass yield, feed intake and survival was assessed. The results indicate that non-salt treated fingerlings along with the 0.25% salt inclusion treatment led to better feed use, as evidenced by apparent feed conversions of 1.64 and 2.02, respectively.
Research highlights: The inclusion of NaCl in pacu fingerling soybean and maize-based diets is not recommended
Soil properties modulate the effect of different carbon amendments on growth and phosphorus uptake by cucumber plant
No full textAim of study: Phosphorus (P) is a non-renewable, limited and strategic resource, inefficiently used in agriculture. Organic carbon (C) supply to soil can stimulate microbial activity increasing the mobilization of soil P thus improving its uptake by crops. This work aimed at investigating the effect of different C amendments on P uptake and how may differ depending on soil properties and P fertilization.
Area of study: Soils used in this study were collected in SW Spain.
Material and methods: An experiment with cucumber was performed involving three factors: (i) C amendment (cellulose, glucose, citric acid and control without amendment), (ii) soil type (Vertisol and Alfisol), and (iii) P supply (unfertilized, and mineral phosphate in form of KH2PO4).
Main results: Cellulose or glucose provided the highest P uptake by plants in soils independently of the treatment. Cellulose and glucose addition was effective increasing dry matter (DM) in the Alfisol. Citric acid application decreased the development of aerial parts and roots, and P uptake in soils compared with other sources. In the Alfisol, increased P uptake with cellulose was associated to an increased concentration of low molecular weight organic acids, which seemed to be related to microbial activity.
Research highlights: Organic amendments affect microbial activity, and P mobilization mechanisms are associated to microorganisms. This explain the improvement of P supply to plants with amendments; these effects, however, are modulated by soil properties and consequently vary depending on soil type
Bayesian analysis of additive and non-additive genetic variances of body weight gain traits in crossbred population of Japanese quail
No full textAim of study: To select the appropriate model for body weight gain (BWG) traits in different ages and estimation of additive and non-additive genetic variances based on the best model, of a crossbred population of quail.
Area of study: Zabol, Iran
Materials and methods: Four strains of Japanese quail, including Italian Speckled, Tuxedo, Pharaoh, and A&M Texas, were used to create a crossbred population in a partial diallel design over 4 generations. BWG traits were calculated as the average growth performance of the bird in a 5-day period from hatch to 45 days of age. Analyses were performed using the Bayesian method by fitting 24 models including the additive and non-additive genetic effects. The deviance information criteria (DIC) was used for the selection of an appropriate model for each trait.
Main results: Based on DIC, the maternal genetic, maternal permanent environmental, dominance and epistasis effects had a significant contribution to the best model for BWG traits before 25 days of age, whereas these effects were not significant on BWG traits at the end of ages. With the best model, direct heritability of BWG traits in different ages ranged from 0.037 (BWG15-20) to 0.199 (BWG5-10). The maternal genetic and maternal permanent environmental as a proportion of phenotypic variance was less than 10% and 5%, respectively. The ratio of dominance and epistasis variance was in the range of 0.016-0.019, and 0.016-0.019, respectively.
Research highlights: Non- additive genetic effects are important for the early BWG traits and must be included in the evaluation models to have accurate estimates
Evaluation of coffee plant attributes by field collection and remotely piloted aircraft system images
No full textAim of study: To verify and evaluate the area occupied by coffee plants before and after the manual harvesting of fruits and the difference between such areas; demonstrate the correlation between data on chemical attributes of leaves, yield, vegetation indices, and areas occupied by coffee plants; and estimate yield based on the variable with the best statistical indicator.
Area of study: Bom Jardim Farm in Santo Antônio do Amparo city, Minas Gerais, Brazil.
Material and methods: We studied 52 sampling points composed of four coffee (Coffea arabica L.) plants each. Field data on leaf chemical attributes, yield, and aerial images of flights with the Remote Piloted Aircraft System were obtained over the study area. The images were processed in the Pix4D software, and the analyses were performed in the ArcGIS and Orange Canvas software.
Main results: We verified a reduction in the area occupied by coffee plants due to the action of the harvest; no significant correlations were detected between leaf chemical attributes, yield data, and area occupied by coffee plants; and only the NDVI was adequate for determining a linear equation to estimate yield.
Research highlights: The yield correlation and predicting estimates by applying vegetation indices optimize the time spent on field measurements using the remotely piloted aircraft system. The fall of leaves due to the action of harvesting was evidenced and promotes impacts on the next crop's yield
Antioxidant properties, element contents and antimicrobial activities of bee pollen collected by Apis mellifera L. in Türkiye
No full textAim of study: Recently, pollen has become a preferred nutritional supplement because of its complex composition. We examined the botanical origin, total phenolic/flavonoid content (TPC/TFC), antioxidant/antimicrobial activity, and element content of pollen samples collected from honeybees. This study also examined whether the elements contained in pollen, when consumed as food, posed a risk to human health.
Area of study: Ten mixed pollen samples were randomly collected from honeybees in the apiaries of four different Turkish regions, which fall among the three phytogeographic regions of Türkiye.
Material and methods: We evaluated total flavonoid (TFC) and phenolic (TPC) contents; antioxidant activities (radical scavenging activity, hydrogen peroxide scavenging activity - HPSA, ferric reducing antioxidant power - FRAP, and ferrous ion chelating activity - FICA), element concentrations and antimicrobial activity.
Main results: According to the melissopalynological analysis, one sample was determined to be unifloral and nine samples were found to be multifloral. The values found ranged 271.42-601.85 mg GAE/100 g TPC, 23.53-34.50 mg CAE/100 g TFC, 22.19-23.78 μg/mL DPPH, 6.50-78.40 µg/mL ABTS, 20.43-150.94 μg/mL HPSA, 97.26-99.83% FRAP and 74.84-91.79% FICA. Rosmanic acid, p-coumaric acid, quercetin, apigenin, and naringin were identified in all samples, while catechin was detected only in S6 and S7. Element contents were found Mg > Fe > Mn > Zn > Cu > Se > Cr > Ni > Cd > Co. All the samples had high antibacterial activity against Bacillus cereus (MIC= 4.17-8.33 g/mL), and against Staphylococcus aureus (MIC= 8.33 g/mL), except S3 and S4.
Research highlights: Different levels and combinations of these components are efficient in the antioxidant and antibacterial activity of pollen
Weed flora in crop rotation and winter wheat monoculture
No full textAim of study: The goal of the study described in this manuscript was to evaluate qualitative and quantitative changes in weed flora infesting winter wheat stands grown in crop rotation and wheat monoculture.
Area of study: South-eastern Poland, Europe (2018-2020).
Material and methods: The experiment was established in the system of randomized blocks (25 m x 6 m) in three replications. Winter wheat was sown in (1) crop rotation (CR): potato – winter wheat – peas – winter barley; and (2) in monoculture (MON). Weed infestation was evaluated in two terms: (1) at the tillering stage and (2) at the waxy maturity stage of winter wheat.
Main results: The number and air-dry weight of weeds evaluated in both terms were higher in MON than in CR. Before wheat harvest, its plots in MON were massively infested by Apera spica-venti and significantly populated by Avena fatua and Anthemis arvensis. In this evaluation term, the weeds of the upper and middle levels accounted for 88.4% of the whole weed community in CR and for 97.7% in MON. In both terms of evaluation, greater biodiversity of the weed community was observed in CR than in MON.
Research highlights: Indicators used to assess the weed flora in crop rotation and monoculture, i.e. weed species composition, number and air-dry weight of weeds, weed distribution in wheat crop levels, and Shannon-Wiener's diversity index
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No full textAim of study: To study the toxic effects of a combined fungicide in Eisenia fetida earthworms and in its lipid fatty acid composition.
Material and methods: We investigated the acute toxicity (LC50, 14 days) of a combined fungicide (active ingredients: carbendazim + cyproconazole) in Eisenia fetida using artificial substrate. The quantitative content of fatty acids (FAs) of body lipids was determined by the method of high-sensitivity gas chromatography.
Main results: Moderate toxicity of the combined fungicide was determined for Eisenia fetida earthworms. Changes in behavioral response, biomass loss, and mortality of test objects were detected. A decrease in the content of saturated FAs was found. At the same time, an increase of long-chain polyunsaturated FAs content of ω6 and ω3 families, which are involved in the regulation of a wide range of physiological processes, was revealed. Modulation of the lipid FAs profile in Eisenia fetida worms is explained by the participation of the FAs in the restructuring of the organism reactivity system under fungicidal load.
Research highlights: The reorganization of the FA profile can be considered as an early criterion of metabolic perturbations in earthworms under the action of fungicides. Understanding the toxic potential of fungicides to organisms in soil ecosystems is essential for practical risk assessment in response to pesticide application
Characterization of the different behaviours exhibited by juvenile flathead grey mullet (Mugil cephalus Linnaeus, 1758) under rearing conditions
No full textAim of study: To describe the common behaviour of flathead grey mullet (Mugil cephalus) under rearing conditions.
Area of study: Tepic, Mexico.
Material and methods: Behaviours exhibited by mullets were videorecorded with submersible cameras installed inside of three tanks. A total of 690 min per day (07:30 - 18:30 h) were recorded per tank during a week. Afterwards, the different behaviours exhibited by juvenile M. cephalus were described, identified and characterized in an ethogram and grouped into two categories: a) locomotion, including three different observed behaviours (resting, swimming and fast swimming) and b) feeding, including three behaviours (surface feeding, bottom feeding and rubbing). Each of the behavioural variables were quantified.
Main results: M. cephalus is a species with a constant locomotion associated to feeding, since fish showed continuous movement during most of day light period. On the contrary, fish exhibited reduced movement during dark periods. Mullets were observed to be a non-aggressive fish species under conditions of the present study, since the absence of dominance and aggression towards conspecifics was observed, which suggested a high predisposition for adaptation to captivity. Finally, behavioural frequencies of grey mullet juveniles were similar among the three tanks for most of the behavioural variables analysed (p>0.05) except for the variable bottom feeding (p=0.02).
Research highlights: Results from this study could be of interest for the aquaculture industry to optimize rearing techniques and welfare for the production of grey mullet
Structural analysis of a mounted moldboard plow using the finite element simulation method
No full textAim of study: Structural analysis of a mounted moldboard plow to redesign and optimise its frame.
Area of study: Shahrekord, Iran
Material and methods: In this study, a complete modeling of a three-bottom moldboard plow was conducted in Solid work 2016 and then, plow-soil interaction model developed in Abaqus 2018. The FEM-simulated draft was compared with the draft calculated by the analytical model.
Main results: The maximum stress and displacement in chassis were determined under different work conditions. The attachment points of the crossbar to the two-lower links of the three-point hitch, the middle of the bottom standard, the head points of the brace and the attachment point of the mast to the top link of the three-point hitch needed to be redesigned. As a result, higher safety factor ranging 2.5-3 is recommended for the mentioned unsafe places.
Research highlights: The obtained results could be used for further studies on the optimization of the moldboard plow frame