Spanish Journal of Agricultural Research
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Responses to different feeding levels during the first month post-insemination in highly prolific multiparous sows
No full textAim of study: To evaluate the impact of the feed level during the first month of gestation on body weight evolution, backfat and loin muscle depths and reproductive performances in highly prolific sows.Area of study: Galicia (Northwestern Spain).Material and methods: Thirty-six Danbred sows were assigned to three experimental groups (n=12) receiving, from day 1 to 30 of pregnancy, 2.5, 3.0 or 3.5 kg/d of a standard diet (8.83 MJ net energy and 138.5 g crude protein/kg). In each group, the number of sows in the second-, third- and fourth-cycle was the same. All animals received, of the same diet, 2.5 kg/d from day 31 to 90 and 3.0 kg/d from day 91 to 107. Seven days prior the parturition, sows were moved to the farrowing-lactating facilities where spent until weaning receiving a common standard lactation diet. At 24 h post-farrowing, litters were standardized to 13 piglets each by cross-fostering.Main results: The optimal feeding level during the first 30 days of gestation was 3.0 kg/d because a lower amount penalized their body weight gain and a higher amount did not improve their fatty reserves. It is worth considering that the increase from 2.5 to 3.5 kg/d generated advantages at birth (higher and more homogenous piglet weights) but also handicaps (lower litter size). The effects were similar irrespective of the cycle number.Research highlights: Different feeding levels during the early pregnancy were tested because it is a critical period. Suppling 3.0 kg/d carried out the best productive and reproductive implications
Nanomaterials. Effective tools for field and horticultural crops to cope with drought stress: A review
No full textDrought is the most serious environmental challenge that limits plant growth and causes more severe yield losses than other abiotic stress factors resulting in a serious food shortage. Nanomaterials (NMs) are considered as vital tools to overcome contemporary and future challenges in agricultural production. Recently, NMs have been applied for enhancing seed germination, growth, physiology, productivity and quality attributes of various crops under normal or stress conditions. Up to date, there is no a comprehensive review about the potential role of NMs in attenuating the drought-induced adverse effects in crop plants. Thus, this review will highlight this issue. Generally, NMs minimize drought-induced osmotic stress by accumulation of osmolytes that result in osmotic adjustment and improved plant water status. In addition, NMs play a key role to improve root growth, conductive tissue elements and aquaporin proteins facilitating uptake and translocation of water and nutrients. Furthermore, NMs reduce water loss by stomatal closure due to abscisic acid signaling. However, this leads to reduced photosynthesis and oxidative stress damage. At the same time, NMs increase the content of light-harvesting pigments, enzymatic and non-enzymatic antioxidants leading to enhancing photosynthesis with reducing oxidative stress damage. Overall, NMs can ameliorate the deleterious effects of drought stress in crop plants by regulation of gene expression and alternation of various physiological and biochemical processes
Short Communication: Frankliniella tenuicornis (Thysanoptera: Thripidae), a novel harmful insect to banana (Musa sp.) crops
No full textAim of study: This study aimed to record a previously unknown harmful insect to banana (Musa sp.) crops, Frankliniella tenuicornis (Uzel).Area of study: Thrips individuals were collected from banana fields located in Paphos District, Cyprus.Material and methods: Specimens of thrips were mounted in permanent microscope and identified using specialized literature. Voucher specimens are deposited in Coleção de História Natural da UFPI, Brazil. Images for species and damage recognition were obtained.Main results: The thrips causes a red-brownish discoloration at the spots where banana fruits touch each other. This cosmetic damage reduces the marketability and/or price of banana fruits. In addition, F. tenuicornis is recorded for the first time in the island of Cyprus.Research highlights: This is the first record of F. tenuicornis damaging banana crops. It constitutes the basic step for future studies in order to produce possible suitable control methods against the new phytosanitary problem
Comparison of different selection methods for improving litter size in sheep using computer simulation
No full textAim of study: To assess selection methods via introgression to improve litter size in native and synthetic sheep breeds.Area of study: Sanandaj, Kurdistan, Iran.Material and methods: Selection approaches were performed using classical, genomic, gene-assisted classical (GasClassical) and gene-assisted genomic (GasGenomic) selection. Litter size trait with heritability of 0.1 including two chromosomes was simulated. On chromosome 1, a single QTL as the major gene was created to explain 40% of the total additive genetic variance. After simulation of a historical population, the animals from the last historical population were split into two populations. For the next 7 generations, animals were selected for favorable or unfavorable alleles to create distinct breeds of A or B, respectively. Then from the last generation, both males and females from breed B were selected to create a native population. On the other hand, males from breed A and females from breed B were mated to simulate a synthetic population. Finally, intra-population selections were carried out based on high breeding values during the last five generations.Main results: The genetic gain in the synthetic breed was higher than that of the native breed under all selection methods. The frequencies of favorable alleles after five generations in the classical, genomic, GasClassical and GasGenoimc selection approaches in the synthetic breed were 0.623, 0.730, 0.850 and 0.848, respectively.Research highlights: Combining gene-assisted selection with classical or genomic selection has the potential to improve genetic gain and increase the frequencies of favorable allele for litter size in sheep
Prediction of soil macronutrients using fractal parameters and artificial intelligence methods
No full textAim of study: To evaluate artificial neural networks (ANN), and k-Nearest Neighbor (k-NN) to support vector regression (SVR) models for estimation of available soil nitrogen (N), phosphorous (P) and available potassium (K).Area of study: Two separate agricultural sites in Semnan and Gorgan, in Semnan and Golestan provinces of Iran, respectively.Material and methods: Complete data set of soil properties was used to evaluate the models’ performance using a k-fold test data set scanning procedures. Soil property measures including clay, sand and silt content, soil organic carbon (SOC), electrical conductivity (EC), lime content as well as fractal dimension (D) were used for the prediction of soil macronutrients. A Gamma test was utilized for defining the optimum combination of the input variables.Main results: The sensitivity analysis showed that OC, EC, and clay were the most significant variables in the prediction of soil macronutrients. The SVR model was more accurate compared to the ANN and k-NN models. N values were estimated more accurately than K and P nutrients, in all the applied models.Research highlights: The accuracy of models among the test stages illustrated that using a single data set for investigation of model performance could be misleading. Therefore, the complete data set would be necessary for suitable evaluation of the model
Short communication: Molecular detection of honeybee viruses in Ecuador
No full textAim of study: The honeybee, Apis mellifera, is one of the most important pollinators in the world. Apicultural activity and pollination services have been affected by the decline in the honeybee population, which may be due to the interaction of multiple risk factors, such as changes in agricultural production, use of pesticides and presence of pathogens. Viruses, in particular, are suspected to be drivers of colony mortality. In this scenario, the aim of this study was to determine the presence of honeybee viruses (IAPV, DWV, SBV, ABPV, BQCV, CBPV) in A. mellifera populations using a RT-mPCR assay.Area of study: Apiaries were situated in Pichincha, Ecuador.Material and methods: Samples were collected from seventeen apiaries that exhibited mortality but without specific clinical signs. Each sample comprised 15 individuals. After RNA extraction, a multiplex PCR analysis was performed for presence of six viruses (IAPV, DWV, SBV, ABPV, BQCV, CBPV).Main results: Four of the viruses (ABPV, DWV, BQCV and SBV) were found in co-infections in these colonies, with ABPV and SBV also being found in simple infections.Research highlights: To our knowledge, this is the first molecular detection of BQCV and SBV in Ecuador. These findings suggest that some of the above viruses could be involved in weakening these colonies
Do haematological profiles of cows in drought prone areas differ with conformation?
No full textAim of study: Severe and frequent droughts have resulted in loss of thousands of rangeland cattle worldwide. The objectives of the current study were to assess the reduction in dimensionality of seven conformation traits and to determine the relationships between extracted constructs and haematological parameters associated with drought resilience in beef cows.Area of study: Muzarabani district, Zimbabwe.Material and methods: Fifty multiparous Mashona cows kept on natural rangelands were used. The collinearity of seven conformation traits of the cows was reduced using principal component analysis. The relationships between the principal components and hematological profiles of the cows were subsequently determined using regression analysis.Main results: First extracted principal component described body capacity (body depth, flank circumference, chest girth). The second component described the frame size (stature and body length) of the cows and the third component was comprised of sheath height and dewlap size. Cows characterised by deep bodies, large flanks and chest girths had low percent haematocrit (HCT), mean capsular haemoglobin concentration (MCHC) and red cell distribution (RDW) (p<0.05). Small-framed cows were associated with low mean platelet volume (MPV), HCT, MCHC and RDW levels in blood (p<0.05). As principal component 3 of conformation traits increased, white blood cell count, mean corpuscular volume, RDW and MPV decreased (p<0.05).Research highlights: Small-framed cows with large thoracic capacities, large dewlaps and belly bottoms far away from the ground surface are able to maintain haematological normalcy under rangelands in drought prone areas
Influence of substrate density and cropping conditions on the cultivation of sun mushroom
No full textAim of the study: To evaluate agronomical features demanded by the sun mushroom (Agaricus subrufescens) in order to optimise the commercial cultivation of this worldwide demanded medicinal mushroom.Area of study: The study was carried out in Castilla-La Mancha (Spain), the second most productive region of cultivated mushrooms in Spain.Material and methods: In this work we summarise the results obtained while evaluating the performance of sun mushroom crops (A. subrufescens). Two agronomical traits have been evaluated, the effect on the productive outputs of applying five different compost filling rates of high N substrate (yield and BE of the compost), and the influence of implementing two different conditions for the induction to fructification on the analytical properties of the harvested mushrooms. Besides, two commercial compost formulations (CM and VC) obtained from local providers have been used.Main results: The number of sporophores harvested and the yield per unit area increased with rising density of compost load, although the biological efficiency was not significantly modified. Compost fill rate of 70 kg m-2 provided an average yield of 13.33 kg m-2 and BE=55.45 kg dt-1, generally higher than those values reported in the literature. The proposed moderate slow induction provides better yields, particularly in the last flushes, and larger sporophores. Proximate analysis of harvested sporophores has not shown significant differences between treatments or factors.Research highlights: As guidance for growers, compost fill weight between 65 and 70 kg per m2 of productive area with a moderate slow induction to fructification is presented as the best option for commercial production under controlled environmental conditions
Short communication: Laboratory evaluation of nine highbush blueberry cultivars susceptibility to Drosophila suzukii (Matsumura, 1931) in the Southwestern Spain
No full textAim of study: To determine how susceptible the most used Southern highbush blueberry (SHB) cultivars were to the spotted wing Drosophila (SWD), Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) as well as those recently introduced to Southwestern Spain.Area of study: Southwestern Spain (Huelva province).Material and methods: Nine of the SHB cultivars which were recently introduced in Southwestern Spain and the most used ones were selected: ‘Arana’, ‘Camellia’, ‘Kirra’, ‘Mayra’, ‘Misty’, ‘O'Neal’, ‘Sharpblue’, ‘Star’ and ‘Ventura’. In order to determine how susceptible the cultivars were to SWD, no-choice tests were performed under laboratory conditions. In addition, berry size, berry firmness, ºBrix, and pH were recorded in order to assess what influence these variables had on oviposition preference by SWD.Main results: Mean clutch size and mean number of emerged adults in ‘Star’ were significantly higher than in the other tested cultivars. ‘Mayra’, ‘Camellia’ and ‘Ventura’ received the lower clutch sizes and mean number of emerged adults. Mean developmental time (egg to adult) differed significantly among tested cultivars and were highest in ‘Camellia’ than in the other tested cultivars. Only firmness and pH were correlated with SWD infestation as females tend to oviposit more eggs in softer fruits than in firmer fruits. Results also showed that a higher pH increased the emergence of adults and shortened the egg to adult developmental time.Research highlights: Our results showed significant differences in the susceptibility of SHB to SWD. This information may help design IPM programs and in making recommendations for blueberry crops as planting of low-chill cultivars expands
Operating leverage and the cost of debt in European agri-food firms
No full textAim of study: To analyse the effect that operating leverage exerts on the cost of debt of agri-food firms in Europe, both in isolation and indirectly through its other risk factors.Area of study: We used panel data made up of 18,360 European firms from 2009 to 2016 (146,880 observations).Material and methods: The data were extracted from the ORBIS database and EUROSTAT. The econometric approach was estimated by the Generalized Method of Moments.Main results: The results obtained confirm that operating leverage or cost structure, in addition to affecting the cost of debt, also affects the relationship between that cost and other sources of risk. More specifically, indebtedness, size, specificity and age all affect the cost of debt to a greater or lesser extent, depending on the level of operating leverage of the company.Research highlights: The main contribution was the study of the cost of external financing as a function of the cost structure, because this directly influences the competitiveness of companies in a key sector of the European economy. We also demonstrated the country effect, taking into account the different policies and practices regarding the assumption of risk by firms. The agri-food sector has been subject to special aid programs of research & development distributed unevenly across countries. If we add to this the national subsidy programs, the level of indebtedness is not a clear determinant of the cost of debt. The main determinant of that cost is the operating leverage