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Industrial-Scale Composting of Rice Straw and Sewage Sludge
Get PDFComposting is an interesting option to recycle big quantities of organic waste because it helps to mitigate different environmental problems. Complementary characteristics of rice straw (RS) and sewage sludge (SS) create a suitable mixture to be used in a composting process. This work studies industrial-scale RS and SS composting to assess both its viability and optimization. Windrow composting was conducted during two seasons. The complete characterisation (moisture, pH, electrical conductivity, total, oxidisable and water-soluble organic carbon, humic substances, organic and mineral nitrogen, macronutrients, micronutrients, heavy metals) of starting materials, samples taken periodically and final composts were carried out. During the first season, an RS:SS ratio of 1:8 (w:w fresh weight) was used, which led to a process with adequate temperatures for biodegradation, but not for ensuring materials’ sanitation. During the second season, the RS:SS ratio was increased (1:6) to enhance the energy process and, thus, temperatures. Although this increase took place, degradation slowed down as oxidisable organic carbon and water-soluble organic carbon indicated. During both seasons, final composts presented adequate pH, high N-richness, and interesting macro- and micronutrient values. Notwithstanding, they also presented certain salinity and high ammonium contents, which must be considered for their field application. The obtained composts have interesting agronomic characteristics, which suggest their potential as an alternative to conventional fertilisers
Protein and amino acids digestibility of two black soldier fly larvae meal forms in broilers
Get PDFA trial was conducted to evaluate the protein (CP) and amino acids (AA) digestibility of two types dehydrated Black Soldier fly (i.e. Hermetia illucens) larvae meal: a defatted meal (DF) and a full fat meal (FF) in broilers. These insects were all fed with agri-food by-products. A total of 140 male broilers of 21 days of age were used. Five experimental feeds were formulated to calculate standardized ileal digestibility (SID) of CP and AA using the regression method. After 7 days of receiving the experimental diets, animals were slaughtered and the terminal ileum content was collected to determine CP and the individual AA digestibility
Efecto del protocolo de refrigeración y de congelación sobre la calidad del semen criocongelado de machos cabríos
Get PDFThe cryopreservation of goat semen plays a crucial role in animal breeding and conservation programs. However, during the freezing and thawing process, the quality of the semen can be affected due to the sensitivity of spermatozoa to low temperatures and changes in cellular structure. In this study, we evaluated the effects of different cooling and freezing protocols on the quality of frozen-thawed goat semen, some using more sophisticated infrastructures and others using simpler methods. Specifically, the aim was to determine the optimal protocol for cooling and freezing goat semen that would result in the highest quality of thawed semen. The semen samples were subjected to cooling at a constant speed in a programmable water bath at 4°C or at a variable speed in a beaker, and then frozen using a programmable freezer or a method involving a Styrofoam box with straws suspended 3 cm above liquid nitrogen. Subsequently, the frozen semen was thawed, and its quality was evaluated using computer-assisted semen analysis (CASA) and membrane integrity assessment by cytometry. The results of the statistical analysis showed no significant differences between the treatments. This indicates that, in this particular study, the different cooling and freezing protocols did not have a significant impact on the quality of the thawed semen, and thus any of them can be used depending on the availability of resources and equipment in each laboratory. With the different protocols studied, similar in vitro semen quality is obtained, enabling its use in the creation of genetic resource banks to conserve genetic diversity in goat populations. However, further research is needed to determine if in vivo fertility is also similar among the different protocols
New insights into short-term water stress tolerance through transcriptomic and metabolomic analyses on pepper roots
Get PDFIn the current climate change scenario, water stress is a serious threat to limit crop growth and yields. It is necessary to develop tolerant plants that cope with water stress and, for this purpose, tolerance mechanisms should be studied. NIBER® is a proven water stress- and salt-tolerant pepper hybrid rootstock (Gisbert-Mullor et al., 2020; López-Serrano et al., 2020), but tolerance mechanisms remain unclear. In this experiment, NIBER® and A10 (a sensitive pepper accession (Penella et al., 2014)) response to short-term water stress at 5 h and 24 h was studied in terms of gene expression and metabolites content in roots. GO terms and gene expression analyses evidenced constitutive differences in the transcriptomic profile of NIBER® and A10, associated with detoxification systems of reactive oxygen species (ROS). Upon water stress, transcription factors like DREBs and MYC are upregulated and the levels of auxins, abscisic acid and jasmonic acid are increased in NIBER®. NIBER® tolerance mechanisms involve an increase in osmoprotectant sugars (i.e., trehalose, raffinose) and in antioxidants (spermidine), but lower contents of oxidized glutathione compared to A10, which indicates less oxidative damage. Moreover, the gene expression for aquaporins and chaperones is enhanced. These results show the main NIBER® strategies to overcome water stress
Influence of Regulated Deficit Irrigation on Arbequina’s Crop Yield and EVOOs Quality and Sensory Profile
Get PDFRegulated deficit irrigation in super-high-density (SHD) olive orchards is a well-known strategy to save water and control plant vigor, without decreasing fruit or oil yield. As there is controversial information about its influence on virgin olive oil quality, a trial was conducted in five SHD olive orchards of Arbequina cultivar in different locations of central, east, north and northeast Spain under full irrigation (FI) and regulated deficit irrigation (RDI) treatments. RDI applied during phase II of fruit growing (40% of total needs) saves more than 20% of water on average, without reductions in olive fruit or extra virgin olive oil (EVOO) yield. No threshold of 3.5 MPa of stem water potential was crossed in any case. RDI modified sterols and the fatty acid profile of EVOOs but not phenols, quality parameters, or the sensory profile. Latitude, altitude, and yearly rainfall have a big impact on some compounds such as campesterol, oleuropein, or margaroleic or linolenic acids
Exclusion of Mediterranean ant species enhances biological control of the invasive mealybug Delottococcus aberiae in citrus
Get PDFBackground: Delottococcus aberiae is an invasive mealybug that produces severe damage in Spanish citrus. This mealybug has established a mutualistic relationship with native Mediterranean ant species that may limit biological control of this pest. Herein, we evaluated the effect of tending ants on the biological control of D. aberiae. To do this, we compared: (I) the density of D. aberiae, (II) the density of its natural enemies, and (III) the damage produced by the mealybug in trees with (control) and without ants (ants excluded with sticky barriers) in two citrus orchards across two consecutive years. Results: Lasius grandis was the most abundant ant species in both orchards and represented more than 95% of the ants tending D. aberiae in control trees. Spiders and lacewings were the most abundant predators observed in mealybug colonies, and the exclusion of mutualistic ants increased their abundance. Moreover, in control trees, ant activity throughout the year was negatively correlated with the relative abundance of predators (number of predators per mealybug). No parasitoids were recovered during field experiments. Ant exclusion reduced the density of D. aberiae and the ratio of damaged fruit at harvest across years and orchards. Conclusions: This work corroborates the previous finding that D. aberiae benefits from its mutualistic relationship with L. grandis, probably because the presence of ants reduced the abundance of generalist predators. This mutualism can be disrupted using physical barriers on the trunk. Further research should assess other methods of ant control that are more economic and feasible for citrus producers
Two Better Than One? Potential Effects of Intraguild Predation on the Biological Control of Ceratitis capitata (Diptera: Tephritidae) by the Parasitoid Aganaspis daci (Hymenoptera: Figitidae) and the Predator Pseudoophonus rufipes (Coleoptera: Carabidae)
Get PDFThe use of more than one species to manage a single insect pest is a common practice
among biological control programs. However, the beneficial effects of natural enemies are not always
additive, which in many cases may be attributed to interspecific interactions such as intraguild
predation (IGP). Herein, we investigated the potential IGP between two relevant natural enemies of
the Medfly (Ceratitis capitata), the predator Pseudoophonus rufipes and the parasitoid Aganaspis daci,
as well as the possible implications of this phenomenon in their efficiency as biocontrol agents. To
this end, we assessed their functional responses and different demographic parameters when acting
alone and together against C. capitata under laboratory conditions. Coexistence led to a switch in the
functional response of both species, from type III to type II in A. daci and the opposite in P. rufipes.
Regarding demographic parameters, coexistence resulted in higher parasitoidism and population
reduction by A. daci only at low host densities, probably due to competition pressure. In the same
circumstances, P. rufipes reduced its predatory activity, rejecting those larvae that were presumably
parasitized and causing negligible IGP. At high Medfly densities, A. daci efficiency decreased, and
the reduced encounter probability enhanced the predatory activity by P. rufipes. As a result of these
trends, Medfly population reduction reached almost 100% at all densities, which suggests an additive
effect of both natural enemies and recommends combined releases of these agents as a strategy for
the control of the Medfly
Characterization of the Epidermis and Cuticle of the Cashew Pseudofruit during Its Development and Maturation
Get PDFThe epidermis and cuticle play an important role in reducing dehydration and protecting
the cashew pseudofruit in both the production environment and the postharvest stage. This study
analyzes the alterations on the epidermis and cuticle of CCP 76 cashew pseudofruits harvested in
five developmental and maturation stages (S1, S2, S3, S4, and S5). The epidermis and cuticle of
the samples were analyzed under light microscopy (LM) (quantitative analysis), scanning electron
microscopy (SEM), and transmission electron microscopy (TEM). The epidermal cells at S3 reached
maximum outer periclinal wall thickness, which reduced during ripening (S4 and S5), while the
cuticle increased in thickness during the same period. These changes coincided with the rapid initial
growth of the cashew pseudofruit when the epidermis and cuticle need to accompany the expansion
of internal tissues. At the ultrastructural level, lipid material is transported via vesicles through the
cell wall to the cuticle, increasing its thickness. Epicuticular waxes, previously deposited as plates
and globules, began to develop an amorphous shape during maturation. This process possibly occurs
due to changes in wax composition that can be related to the development of greasiness on the fruit
skin. These findings provide a better understanding of cashew pseudofruit skin, which will aid future
studies and strategies to preserve quality during the postharvest stage
Cambios en la microbiota intestinal provocados por la inclusión de dos tipos de orujo de aceitunas en alimentación de cerdos
Get PDFIn vivo rabbit embryo production and cryopreservation review. Application to ex situ conservation and rederivation
Get PDFThe development of reproductive technologies in this species is contributing decisively to the development of rabbit farming and the preservation of genetic resources. Obtaining embryos is an essential step to both genetic diffusion and the preservation of genetic resources from genetic erosion or natural disasters. In rabbits, it is common for embryos to be recovered post-mortem after ovarian hyperstimulation with gonadotrophins, although the quality and number of embryos are variable, affecting the embryo viability and offspring rate by the donor. In vivo embryo production within a conservation programme aims not only to obtain a large number of embryos, but also that they come from a greater number of male and female origins, in order to ensure an adequate representation of the original population. This is why both the quality and quantity of embryos obtained per donor rabbit and the rate of donors with offspring after embryo cryopreservation must be considered, as well as the response of the embryos to the chemical, physical and physiological stress to which they are subjected in the rederivation process and its postnatal repercussions on those that survive. Rederived rabbits from cryopreserved and transferred embryos showed phenotypic growth changes, which calls into question the neutrality of the technique and its usefulness in those cases in which a control population is required