Spanish Journal of Agricultural Research
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Geographical proximity on the valuations of unlisted agrarian companies: Does distance from company to company and to strategic points matter?
No full textThis paper is a first attempt to examine the role played by the geography on agrarian firms’ valuations. The geography was evaluated through the physical proximity from agrarian companies to other companies and to some strategic points which ease their accessibility to external economic agents. To get our purpose, we developed an empirical application on a sample of non-listed agrarian Spanish companies located in the region of Murcia over the period 2010-2015. We applied Discount Cash Flow methodology for non-listed companies to get their valuations. With this information, we used spatial econometric techniques to analyse the spatial distribution of agrarian firms’ valuations and model the behavior of this variable. Our results supported the assertion that agrarian firms’ valuations are conditioned by the geography. We found that firms with similar valuations tend to be grouped together in the territory. In addition, we found significant effects on agrarian firms valuations derived from the geographical proximity among closer agrarian companies and from them to external agents and transport facilities
Effects of light-diffusing plastic film on lettuce production and quality attributes
No full textIn general, plants grown under diffuse light yield higher biomass than those grown under direct light as a result of a more uniform distribution of the light across the plant canopy. We compared the effects of a light-diffusing plastic film and a clear plastic film on growth of Batavia lettuce (Lactuca sativa L.) in two greenhouses during five growth periods. Lettuce grown under the light-diffusing film were smaller (up to 36%) than control plants grown under the clear film, due to the fewer leaves per plant (up to 22%) and lower mean values of individual leaf area (up to 29%). The photosynthetically active radiations use efficiency was sometimes lower (up to 23%) in lettuces grown under the light-diffusing film. The pigment contents tended to be lower in plants grown under the light-diffusing plastic. The total macroelement contents of the lettuces grown under the light-diffusing plastic were up to 10% higher than in the lettuces grown under clear plastic, mainly as a result of higher leaf K contents (up to 19% higher). In addition, use of the light-diffusing plastic tended to increase leaf nitrate contents (by up to 23%). The leaf solid soluble content and acidity values were higher in the lettuces grown under the light-diffusing plastic, while leaf pH values were lower than in the control plants. The findings showed that the light-diffusing plastic was detrimental to production of compact heads of lettuce, and to some quality parameters such as nitrate and pigment contents. Nevertheless, open-leaf cultivars would likely show a different response to the diffuse light
Yield and profitability of ‘Conference’ pear in five training systems in North East of Spain
No full textTraining systems are key to manage the tree canopy to take advantage of the tree productivity potential. Assessment of yearly cropping, labor requirements, fruit quality, and orchard profitability were studied. The experiment was organized in a randomized complete block design with three replications. Five different training systems on Quince EMC rootstock and ‘Conference’ as the scion cultivar were compared. The results of this study show that the use of preformed highly feathered trees is an improvement for both, early cropping and profitability. Planting cost, trellis, and labor requirements had a large impact on the economic viability of each system. Tatura produced high yields, but the strong initial investment that needs to be done at planting makes this system a risky investment. Axis 2 seems to be the most suitable system for early cropping while maintaining intermediate plantation costs and an appropriate level of production efficiency
Genotype by environment interaction in sunflower (Helianthus annus L.) to optimize trial network efficiency
No full textModeling genotype by environment interaction (GEI) is one of the most challenging aspects of plant breeding programs. The use of efficient trial networks is an effective way to evaluate GEI to define selection strategies. Furthermore, the experimental design and the number of locations, replications, and years are crucial aspects of multi-environment trial (MET) network optimization. The objective of this study was to evaluate the efficiency and performance of a MET network of sunflower (Helianthus annuus L.). Specifically, we evaluated GEI in the network by delineating mega-environments, estimating genotypic stability and identifying relevant environmental covariates. Additionally, we optimized the network by comparing experimental design efficiencies. We used the National Evaluation Network of Sunflower Cultivars of Uruguay (NENSU) in a period of 20 years. MET plot yield and flowering time information was used to evaluate GEI. Additionally, meteorological information was studied for each sunflower physiological stage. An optimal network under these conditions should have three replications, two years of evaluation and at least three locations. The use of incomplete randomized block experimental design showed reasonable performance. Three mega-environments were defined, explained mainly by different management of sowing dates. Late sowings dates had the worst performance in grain yield and oil production, associated with higher temperatures before anthesis and fewer days allocated to grain filling. The optimization of MET networks through the analysis of the experimental design efficiency, the presence of GEI, and appropriate management strategies have a positive impact on the expression of yield potential and selection of superior cultivars
Effect of space allowance during transport and fasting or non-fasting during lairage on carcass contamination and meat traits in Merino lamb
No full textA total of 72 Merino breed male lambs were used in this work, to study the effect of the space allowance during transport [(SA): low (SAL: 0.16 m2/animal; n=24); medium (SAM: 20 m2/animal; n=24); high (SAH: 0.30 m2/animal; n=24)], and the management during 18 h lairage [(TL): fasting (TL-FAST; n=36) vs feeding (TL-FEED; n=36)] on carcass microbial contamination (total viable count, Enterobacteriaceae and Pseudomonas) and meat quality. Carcasses contamination determination was carried out by swabbing (neck, flank and rump). Meat quality was assessed by pH, colour coordinates, drip loss (DL), shear force (SF) ad lipid oxidation. SA did not have effect on carcass microbiological quality. TL caused a significant effect on total viable count and Pseudomonas spp values. Flank was the most contaminated site. SAL-FEED group showed the highest values of drip loss and lipid oxidation. At 24 h post-mortem, pH values were the highest in fasted lambs. At 7 d post-mortem the lowest pH was found in SAM-FAST group while the highest in SAM-FEED. TL had no effect on SF, DL neither on lipid oxidation values. These results could help to meat industry to decide the best management as in the transportation as during lairage before lambs slaughter
Effect of Mycobacterium avium subsp. paratuberculosis serostatus on carcass weight and conformation and fat cover scores
No full textThe paper was designed to assess the influence of Mycobacterium avium subsp. paratuberculosis (MAP) infection status of cows at culling (antibody positive vs negative) on carcass traits: weight and conformation and fat cover scores. A generalized least squares linear model was used to assess the influence of MAP on weight. Subsequently, a random effects logistic regression was completed in order to model the relation between MAP and conformation score (fair vs poor carcasses). A random effects ordered logistic model was used to estimate the influence on fat cover. The results indicated that seropositives had carcass weights 58.45 (34.65-83.35) kg lower than seronegatives. Regarding conformation score, the odds of having poor conformation instead of fair was 3.85 (1.35-11.85) times higher in seropositives. The odds of seropositives achieving a higher fat cover was approximately 5 (1.41-9.09) times lower than the odds for seronegatives. The estimated effects could be useful when assessing the economic benefits of a paratuberculosis control program
Yield, flesh parameters, and proximate and fatty acid composition in muscle tissue of wild and cultured Vieja Colorada (Cichlasoma festae) in tropical Ecuadorian river
No full textThis study was conducted to determine the composition of cultured and wild Cichlasoma festae in Ecuador. The mean slaughter yield and dress-out were similar for cultured and wild specimens and the average fillet fat content for cultured fish was significantly higher compared to the wild fish. The pH, fillet color, drip loss and coked loss were similar between populations. Significant differences were found in protein, lipid and ash content in both studied populations. This study showed that saturated fatty acid (SFA) was higher than sum of monounsaturated (MUFA) and polyunsaturated fatty acid (PUFA) in both populations. Palmitic, oleic and linoleic acids had the maximum percentage of SFA, MUFA and PUFA respectively. In cultured and wild fish was also found to differ in the PUFA/SFA, docosahexaenoic acid/eicosapentaenoic acid, n-3/n-6 ratios and atherogenicity and thrombogenicity indices. Minerals included Ca, P, K, Mg, Zn, Fe, Cu and Mn. There were significant differences in the first six ones. The production system (cultured or wild) influences significantly most of the analyzed characteristics of carcass and flesh of C. festae. These results provide valued nutritional information of native species to produce sources of food with low-fat and high-protein, and safety food for the consumers in Ecuadorian country
Prevalence and risk factors for stillbirths in Holstein cows in a hot environment
No full textRisk factors for stillbirth were studied in a dairy operation in northern Mexico (25°N). Data set consisted of 29406 full term calving records. Factors affecting stillbirths were analyzed using a step-wise multivariable logistic regression models. The predictive indicators of stillbirth risk were: temperature-humidity index (THI) during pregnancy and at calving, season of calving, calf birth weight, gestation length, semen characteristics (conventional or sexed), gender of calves, hour of calving and type of parturition (normal or dystocic). Throughout the study period, 7.3 (95%, confidence interval= 7.0–7.6) of every 100 calving events had a stillborn calf. Stillborns were higher with severe dystocia compared with non-assisted births (29.0% vs. 6.2%, p<0.0001) and calves with birth weights <35 kg compared with heavier calves at calving (19.3% vs. 2.3%, p<0.0001), and was lower in calves whose gestation length was >278 d compared with calves with shorter gestation periods (2.8% vs. 30.0%, p<0.0001). Cows in a severe state of heat stress prenatally and at birth (THI >83 units) had 1.3 higher risk of stillbirths than cows suffering reduced heat stress (p<0.0001). Evidence for a greater (p<0.001) stillbirth rates in cows with parturitions between 18:00 and 19:00 h compared with cows calving during other hours of the day was found (9.1% vs. 7.1%). Together, these results demonstrate that ameliorating heat stress during the peripartum period is an important management practice to reduce stillbirths in Holstein cows in this warm climate. Additionally, a greater attention of parturition around sunset can lower the current stillbirth rates
Bovine viral diarrhea virus (BVDV) genetic diversity in Spain: A review
No full textBovine viral diarrhea virus (BVDV), a member of the genus Pestivirus of the family Flaviviridae, causes significant losses in cattle farming worldwide because of reduced milk production, increased mortality of young animals and reproductive, respiratory and intestinal problems. The virus is characterized by an important genetic, and consequently antigenic and pathogenic diversity. Knowing the variability of viral strains present in a population provides valuable information, particularly relevant for control programs development, vaccination recommendations and even identification of likely infection sources. Such information is therefore important at both local and regional levels. This review focuses on the genetic diversity of BVDV isolates infecting cattle in Spain over the last years. According to the published data, the most prevalent BVDV group in Spain was 1b, and to a lesser extent 1d, 1e and 1f. Besides, BVDV-2 has also been found in Spain with several ratified isolates. The studies carried out in Spain also showed increased genetic heterogeneity of BVDV strains, possibly due to a more intensive use of analytical tools available, presenting studies with increasingly greater sample sizes
Root and aerial growth in early-maturing peach trees under two crop load treatments
No full text The objectives of the paper were to study the pattern of root growth (measured by minirhizotrons) in relation to trunk, fruit and shoot growth and the effects of crop load on tree growth and yield in peach trees. Two crop load (commercial and low) treatments were applied in a mature early-maturing peach tree orchard growing in Mediterranean conditions. Root growth dynamics were measured using minirhizotrons during one growing season. Shoot, trunk and fruit growth were also measured. At harvest, all fruits were weighed, counted and sized. Roots grew throughout the year but at lower rates during the active fruit growth phase. Root growth was asynchronous with shoot growth, while root and trunk growth rates were highest after harvest, when the canopy was big enough to allocate the photo-assimilates to organs that would ensure the following season’s yield. Shoot and fruit growth was greater in the low crop load treatment and was accompanied by a non-significant increase in root growth. High level of fruit thinning decreased the current yield but the fruits were more marketable because of their greater size