Spanish Journal of Agricultural Research
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Performance, carcass characteristics, economic margin and meat quality in young Tudanca bulls fed on two levels of grass silage and concentrate
No full textThis study investigates the effect on performance, carcass and meat characteristics of increasing the forage level in the diet of fattening Tudanca young bulls using silage as the forage source as compared with a conventional ad libitum straw plus concentrate diet. Twenty two Tudanca young bulls were assigned to three different finishing diets: ad libitum grass silage plus ad libitum concentrate (GS-AC), ad libitum grass silage plus concentrate limited to a half of the intake of the ad libitum group (GS-LC), ad libitum barley straw plus ad libitum concentrate (Str-AC) and then slaughtered at around 11 months of age. GS-LC diet resulted in relation to GS-AC and Str-AC diets in lower (p≤0.05) average daily weight gain (750 vs 1,059 and 991 g/animal/day, respectively), lower (p≤0.05) carcass weight (133 vs 159 and 152 kg, respectively) and carcasses with slightly lower conformation scores. Although GS-LC diet allowed for a lower dependence on concentrate (372 vs 657 and 729 kg/animal, respectively), economic margin was similar for the two GS groups (-63.1 and -64.1 vs -91.8 €/head). The polyunsaturated/saturated fatty acid ratio was the lowest (p≤0.05) in GS-AC meat (the group showing the highest IMF levels) and the ratio n-6/n-3 was the highest (p≤0.05) in Str-AC meat. GS-LC meat showed higher collagen content and Str-AC meat presented higher cohesiveness, springiness and chewiness values. Results suggested that the substitution of straw by grass silage and the restriction of the concentrate level could be recommended for finishing young Tudanca bulls in indoors systems
Fuzzy clustering algorithm to identify the effects of some soil parameters on mechanical aspects of soil and wheat yield
No full textIn this paper, site-specific management zones (MZs) were delineated in three fields belonging to a farm in the center of Italy and characterized by different soil texture. Crop yield and various soil parameters, both physical (soil structural stability, clay fraction, water content, and organic matter) and mechanical (shear strength and penetration resistance) were monitored. Yield data were acquired by means of a combine harvester equipped with a precision land management system during three consecutive growing seasons. At the end of the third growing season, soil properties were investigated by means of georeferenced soil sampling. After data gathering, a fuzzy clustering algorithm was applied to define management zones. Results highlighted spatial variability between the three fields and temporal variability between the three consecutive growing seasons. Whilst the latter could be ascribed to the rainfall distribution (therefore moisture could be considered as a limiting factor in wheat growth), the delineated MZs suggest that clay content and organic matter could affect both mechanical parameters of soil and crop yield. The defined MZs can serve as a basis to generate prescription maps for variable-rate application inputs and variable tillage
Factors influencing the stay-exit intention of small livestock farmers: empirical evidence from southern Chile
No full textThis study analyses the factors driving the stay-exit intention of small livestock farmers located in southern Chile. Technical, economic, and social characteristics from 212 farmers were included in this study. Through an empirical probit model we identified the variables that should be considered when developing rural policies aimed at increasing the likelihood to stay in farming. The results showed that 12 out of the 30 parameters were significant (p<0.10), with an extremely good fit of the model (McFadden pseudo-R2 = 0.25, Count R2 = 75.9%). Particularly, ‘female farmer’, ‘positive expectation about future farming life’, ‘capacity of farm income to cover the expenses of the whole family’, ‘mixed production’, ‘participation in an association’, and ‘distance to the nearest city’ were positively associated with the stay intention. Moreover, our study also indicates that ‘existence of a defined retirement age’, ‘existence of a defined sale price for the farm’, ‘a mixed farm focused on livestock production’, ‘the possibility to make own decisions’, ‘age squared’, and the ‘number of people living at the farm’ were negatively associated with the stay intention. Our empirical findings suggest that farmer characteristics (gender, family size), the farming system (multi-activity production, efficiency), and social aspects of the rural society (associations, protection of agricultural products) are also important aspects that should be considered by rural development policies aimed at improving the likelihood of staying, in addition to the technical characteristics of the farming which have been traditionally addressed in developing countries
Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens
No full textThe present work examines the variations in the aerodynamic characteristics of four insect-proof screens by means of wind tunnel tests and digital image processing. The tested insect-proof screens were examined in three different conditions: (i) in their new, unused state; (ii) under conditions of accumulated dust and dirt after a period of 3 to 4 years of use; and (iii) under clean conditions after a period of 3 to 4 years of use and a cleaning treatment with high-pressure water. The deterioration of the screens caused the mesh to become less tense, therefore increasing its thickness and improving its aerodynamic behaviour despite a slight increase of the thread diameter and a subsequent decrease of the 2-dimensional porosity. The pressure drop coefficient, Fφ, of the used but clean screens was 1.5% to 8.8% lower (for u=1.0 m/s) than that of the new ones, thus increasing the discharge coefficient, Cd,φ, by between 0.8% and 4.8% as a result of the presence of the screens. On the other hand, comparison of the used screens in their clean and unclean states showed that the accumulation of dirt has a major bearing on their aerodynamic characteristics: Fφ increased by between 16.5% and 61.2% (for u=1.0 m/s) for the unclean screens, resulting in a Cd,φ reduction of between 7.5% and 21.3% and therefore a lower natural ventilation capacity of the greenhouse. A regular cleaning treatment of the insect-proof screens is a simple measure that improves the natural ventilation capacity of the greenhouse
Farmers’ willingness to pay for surface water in the West Mitidja irrigated perimeter, northern Algeria
No full textAlgeria is among the most water-stressed countries in the world. Because of its climatic conditions, irrigation is essential for agricultural production. Water prices paid by farmers in public irrigation districts are very low and do not cover the operation and maintenance (O&M) costs of the irrigated perimeters, thus leading to the deterioration of these infrastructures. The objective of this paper is to analyse whether farmer’s in the West Mitidja irrigation district in northern Algeria would be willing to pay more for surface water in order to maintain the water supply service in its current conditions. We estimated farmers’ willingness to pay (WTP) for water using data from a dichotomous choice contingent valuation survey to 112 randomly selected farmers. Farmers’ responses were modelled using logistic regression techniques. We also analysed which technical, structural, social and economic characteristics of farms and farmers explain the differences in WTP. Our results showed that nearly 80% of the surveyed farmers are willing to pay an extra price for irrigation water. The average WTP was 64% greater than the price currently paid by farmers, suggesting some scope for improving the financial resources of the Mitidja irrigated perimeter, but insufficient to cover all O&M costs. Some of the key identified factors that affect WTP for surface water relate to farm ownership, access to groundwater resources, cropping patterns, farmers’ agricultural training and risk exposure
Climatic regionalization of wine grapes in the Hengduan Mountain region of China
No full textThe Hengduan Mountain region of China is one of the world's highest altitude and lowest latitude wine grape cultivation areas. This study screened the existing regional indexes; the active accumulated temperature (AAT) for grapes in the growing season was chosen as the heat index, and the dryness index (DI) in the growing season was chosen as the water index for climatic regionalization. An analysis of 90-meter resolution digital elevation model (DEM) data and the corresponding slope degree and direction for the Hengduan Mountain region in the range of 97°E-103°E, 27°N-33°N, as well as daily meteorological data over 30 years (1981-2010) from 53 stations in the study region, were used to establish the AAT and DI models for the northern area of the Hengduan Mountains. According to the multiple stepwise regression method, the interaction terms among different geographical and topographic factors were considered. In addition, the residual errors were interpolated and corrected based on the modeling, and this approach further improved the simulation accuracy of meteorological factors. A regional climatic map of wine grapes was produced according to these results. The model was used to calculate the suitable altitude range for wine grape cultivation in different regions of the Hengduan Mountains. The study shows that the distribution of suitable wine grape cultivation areas in the northern part of the mountain range generally mimics distribution of dry warm and dry hot valleys. The accuracy of the results was confirmed based on the existing locations of vineyards in the Hengduan Mountain region
Deficit irrigation in commercial mandarin trees: water relations, yield and quality responses at harvest and after cold storage
No full textTwo experiments were conducted on a commercial farm of late ‘Fortune’ mandarin trees in order to know the response of regulated deficit irrigation (RDI), mainly applied during the most harmful ripening stages, on plant water relations, yield and fruit quality at harvest and after cold storage at different temperatures. Control trees were irrigated to satisfy maximum crop evapotranspiration, while RDI-1 and RDI- 2 represented a 20% and 40% reduction, respectively, in the water applied. Total yield and fruit quality at harvest were not significantly affected by either treatment. Late stage II of fruit growth was the most sensitive period to water stress, while deficit irrigation applied during flowering and stage I of fruit growth resulted in a significantly higher number of fruits per tree and an improvement in irrigation water productivity compared with the Control treatment. In both experiments, skin chroma decreased during cold storage, at the same time as titratable acidity fell. Fruit quality (titratable acidity, skin C* and ascorbic and glutamic acids) were more affected by cold storage than by differences between the RDI treatments. The use of trunk diameter fluctuation was useful for restoring the RDI irrigation to levels of the Control at the end of early stage II. From a quality point of view, any difference between treatments found at harvest tended to diminish during the subsequent shelf-life after cold storage. Quality traits (titratable acidity, ascorbic and glutamic acid) could be used as chilling biomarkers
Short communication: Morphometric characterization of Lidia cow (Bos taurus) reproductive apparatus
No full textTo study Lidia cow reproductive apparatus traits, a total of 90 organs were collected after slaughtering the cows from different Bos taurus breeds: (i) Lidia cattle breed - Brava dos Açores population (n=10) and Domecq lineage (n=11); (ii) Holstein Friesian females – 10-14-month-old heifers (n=15); 15-20-month-old heifers (n=10), 21-19-month-old heifers (n=18), and (iii) cows ≥ 30 months (n=26). The length and width were measured for five portions of the female reproductive apparatus (vulva and vagina, cervix, uterine body, uterine horns and ovaries). One-way ANOVA was performed with Tukey test. The level recognized to assume differences was p<0.05 to less. Differences were not shown between Lidia groups. In general, the Lidia cow reproductive apparatus was small in size that that of the matured cows in terms of all traits, with the exception of cervix rings (5.10 ± 0.17 rings) with p≤0.01 for all the groups (averages ranged from 3.33 ± 0.11 rings to 3.50 ± 0.15 rings). The vulva and vagina (L= 27.31 ± 0.53 cm; W=2.07 ± 0.14 cm), the uterine body width (3.01 ± 0.18 cm) and the uterine horns (L= 12.24 ± 0.32; W= 1.13 ± 0.10) showed were smaller in size than those of the evaluated heifers from HF breed that ranged in age from 10 to 14 months (p≤0.01). This study was the first to perform a morphometric characterization on the Lidia cow reproductive apparatus, and the results provide useful information for understanding reproductive approaches to be used with this breed
Sperm quality and seminal plasma proteins in three sheep breeds under high altitude and tropical conditions
No full textWe tested the hypothesis that sheep breed can influence the sperm quality and seminal plasma (SP) composition and investigated any potential relationship between SP proteins and antioxidant enzyme activities (AO) with sperm quality. Ejaculates from twelve rams of three breeds were obtained during the rainy season at high altitudes, and sperm quality was automatically evaluated (CASA-Hamilton Thorne). The AO of superoxide dismutase, glutathione peroxide and glutathione reductase (GR) in SP was evaluated and total proteins were separated by SDS-PAGE. Comparative analyses of semen quality parameters between breeds revealed that Creole and Hampshire breeds had a higher sperm quality compared with Romney Marsh (p<0.05), although no difference in AO was found. GR activity was negatively correlated (p<0.05) with several kinematic variables and positively (p<0.05) with morphological abnormalities. The highest SP protein concentration was found in semen collected from Hampshire males compared with that from Creole and Romney Marsh (p<0.05). SDS-PAGE analysis showed the presence of 32 protein bands in SP with molecular weights between 334 and 10 kDa. Differences (p<0.05) between breeds in bands of 43, 25, 22 and 20 kDa were observed. These results evidence a relationship between the protective effect of the antioxidant enzyme system in SP of three ram types under high altitude and tropical conditions and semen quality. Our findings also suggest that the identified proteins might play an important role in sperm physiology and quality
Short communication: Efficacy of a non-pheromone semiochemical for trapping of western flower thrips in the presence of competing plant volatiles in a nectarine orchard
No full textNon-pheromone semiochemicals or allelochemicals (kairomones, synomones, allomones) are often derived from, or are similar to, host plant odours and depending on their use, these semiochemicals may have to compete with the same or similar odours emanating from adjacent host plants with unknown consequences on trapping efficacy. The aim of this study was to examine the efficacy of the non-pheromone thrips attractant methyl isonicotinate (MI) as a lure for Western flower thrips (WFT; Frankliniella occidentalis) over a range of Prunus persicae nectarine plant growth stages (flowering, green fruit, ripe fruit), when competition from different host plant odours may vary, and different numbers of thrips can be present, in a Catalan nectarine orchard in 2014 and 2015. Significant 2.4–3.9 × increases in WFT numbers in traps with MI compared with those without MI were consistent over the season (flowering, green fruit, mature fruit) despite overall differences in thrips numbers on these different occasions. These results suggest that MI is an effective lure throughout the nectarine growth stages despite the presumed presence of competing and changing host plant odours. Trap type and colour and MI release rate may be important for improving overall trap efficacy