Spanish Journal of Agricultural Research
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Short communication: Influence of the sampling device on somatic cell count variation in cow milk samples (by official recording)
No full textThe objective of this study was to investigate the variability in cow´s milk somatic cell counts (SCC) depending on the type of milk meter used by dairy farms for official milk recording. The study was performed in 2011 and 2012 in the major cattle area of Spain. In total, 137,846 lactations of Holstein-Friesian cows were analysed at 1,912 farms. A generalised least squares regression model was used for data analysis. The model showed that the milk meter had a substantial effect on the SCC for individual milk samples obtained for official milk recording. The results suggested an overestimation of the SCC in milk samples from farms that had electronic devices in comparison with farms that used portable devices and underestimation when volumetric meters are used. A weak positive correlation was observed between the SCC and the percentage of fat in individual milk samples. The results underline the importance of considering this variable when using SCC data from milk recording in the dairy herd improvement program or in quality milk programs
Application of electrical capacitance measurement for in situ monitoring of competitive interactions between maize and weed plants
No full text Applicability of root electrical capacitance (EC) measurement for monitoring of crop–weed competition was studied in a pot experiment. Maize (Zea mays L.) was grown both alone and with Echinochloa crus-galli or Abutilon theophrasti in different densities with regular measurement of root EC. Plants were harvested 42 days after planting to determine above- and belowground biomass. Depending on weed density, E. crus-galli-A. theophrasti interaction reduced the root EC of maize by 22–66% and 3–57%, respectively. Competitive effect of crop on weeds and intraspecific competition among weeds could also be detected by EC values: E. crus-galli was less sensitive both to the presence of maize and to intraspecific competition than A. theophrasti. Strong linear correlations between root dry mass and root EC for crop and weeds (with R2 from 0.901 to 0.956) were obtained by regression analyses at the end of the experiment. EC monitoring informed us on the emergence time of competition: E. crus-galli interfered with maize root growth a week earlier then A. theophrasti, and increasing weed densities accelerated the emergence of competition. In conclusion, the simple, non-destructive EC method should be considered a potential in situ technique for pot studies on crop–weed competition, which may partially substitute the intrusive techniques commonly used in agricultural researches
The “Criollo Negro de la Costa Ecuatoriana” pigs. Performance, carcass and meat traits
No full textThe objective of this study was to evaluate the effect of rearing system (confinement, C vs semi-confinement, SC) and sex (barrows vs females) on growth performance, carcass traits and meat quality of “Criollo negro de la costa ecuatoriana” pigs. A total of 32 pigs, 16 barrows and 16 gilts were used. The average daily gain (0.30 kg/day vs 0.22 kg/day), slaughter weight (51.4 kg vs 43.1 kg), morphometric parameters and weights for the most valuable meat cuts were higher in C pigs than in SC pigs, whereas hot and cold carcass yields were higher in SC pigs than in C pigs. The loin and sirloin percentages from C pigs were lower and higher compared with those SC pigs, respectively. Carcass of C pigs showed higher percentage of fat and lower percentage of lean and bone that SC pigs. The rearing system had scarce effects on meat quality traits and mineral composition. Meat from C pigs showed lower scores for color, brightness, and unctuousness, and higher for metallist taste, juiciness and persistence of flavor than SC pigs. Few sensory attributes of cooking chops were affected by sex. Metallist taste was higher in barrows, while brightness and lard flavor were higher in females. It can be concluded that the rearing system had a significant effect on most of the productive and carcass traits, whereas its effect was limited on the meat traits. Sex had little influence on most of the traits studied.A total of 32 Creole pigs were used to evaluate the effect of rearing system and sex on carcass and meat traits. 8 males and 8 females were reared in a semi-confinement system (SC), and a second group (8 males and 8 females) was reared indoors (C). The C pigs showed a better growing rate (0.3 kg/d vs. 0.22 kg/d) and final live weight, as well as higher morphometric parameters, and superior weights for the most valuable meat cuts to those of SC pigs, while showed a lower hot and cold carcass yields. The loin and sirloin percentages from C pigs were lower and higher compared with those SC pigs, respectively. Carcass of C pigs showed higher percentage of fat and lower percentage of lean and bone that SC pigs. The rearing system did not affect the meat quality traits and mineral composition. Meat from C pigs showed lower scores for color, brightness, and unctuousness, and higher for metallist taste, juiciness and persistence of flavor than SC pigs. Few sensory attributes of cooking chops were affected by gender. Metallist taste was higher in males, while brightness and lard flavor were higher in females
Pruning for crop regulation in high density guava (Psidium guajava L.) plantation
No full textHigh density management and crop regulation are two important aspects in guava (Psidium guajava L.) production. Therefore, to find out the economic way of managing high density planting and crop regulation, the present work was carried out on 6-year-old guava trees of cv. Pant Prabhat under double-hedge row system of planting during 2009-10 and 2010-11. Seven different forms of pruning [FBT: flower bud thinning by hand, FBTT: flower bud thinning by hand followed by removal of terminal one leaf pair, RLFO: removal of leaves and flower buds by hand, retaining one leaf pair at the top, RLF: removal of all leaves and flowers by hand, OLPS: one leaf pair shoot pruning, FSP: full shoot pruning, OLPF: one leaf pair pruning of fruited shoots only] were studied along with control (C).Minimum annual increase in tree volume (6.764 m3) was recorded with the treatment OLPF, which was 2.31 times less than the control (15.682 m3). Highest yield during winter season (55.30 kg/tree) and total yield (59.87 kg/tree) was obtained from treatment OLPF. One leaf pair pruning of fruited shoots only (OLPF) was also found profitable among other treatments by recording cost:benefit ratio of 1:2.96. This treatment also recorded the highest return distributed in rainy as well as in winter season. On the basis of findings it can be concluded that one leaf pair pruning of fruited shoots only is suitable for profitable high density management as well as crop regulation of guava in farmer friendly manner
Are the eating habits of university students different to the rest of the Spanish population? Food availability, consumption and cost
No full textKnowledge of the eating habits of young people is highly relevant to understand the demand for food. The objectives of this paper are to identify and analyze the eating habits of a section of young people in relation to the food habits of the rest of the Spanish population, to evaluate the influence of food prices on eating habits and the relevance of those food products related to the Mediterranean diet. The three food surveys used in this study were the Food Balance Sheet (FBS), designed by the FAO, the Household Budget Survey (HBS), designed by the Spanish National Institute of Statistics and an individual survey given to enrolled students at the University of Castilla-La Mancha. The cross-sectional study which was carried out allowed us to discover the cost of food and the consumption habits of a section of young people. A change in food availability and consumption was identified between 2009 and 2012. The average availability per capita and day for food expenditure was €6.19, while the average consumption in the two surveys was €4. The average food availability was 125.58 g per capita and day with an average price of 0.0022 €/g. The behavior of these university students is different from that of the rest of the population. Fruits, legumes, vegetables and greens are the cheapest groups of food; however, the consumption of these food groups is the lowest whereas meat is one of the more expensive groups and is consumed in greater quantities by students. These results are relevant in order to encourage the dietary habits of young people towards the products included in the Mediterranean diet
Imaging technologies to study the composition of live pigs: A review
No full textImage techniques are increasingly being applied to livestock animals. This paper overviews recent advances in image processing analysis for live pigs, including ultrasound, visual image analysis by monitoring, dual-energy X-ray absorptiometry, magnetic resonance imaging and computed tomography. The methodology for live pigs evaluation, advantages and disadvantages of different devices, the variables and measurements analysed, the predictions obtained using these measurements and their accuracy are discussed in the present paper. Utilities of these technologies for livestock purposes are also reviewed. Computed tomography and magnetic resonance imaging yield useful results for the estimation of the amount of fat and lean mass either in live pigs or in carcasses. Ultrasound is not sufficiently accurate when high precision in estimating pig body composition is necessary but can provide useful information in agriculture to classify pigs for breeding purposes or before slaughter. Improvements in factors, such as the speed of scanning, cost and image accuracy and processing, would advance the application of image processing technologies in livestock animals
Short communication: Survival of honey bees (Apis mellifera) infected with Crithidia mellificae (Langridge and McGhee: ATCC® 30254™) in the presence of Nosema ceranae
No full textCrithidia mellificae, a trypanosomatid parasite of Apis mellifera, has been proposed to be one of the pathogens responsible for the serious honey bee colony losses produced worldwide in the last decade, either alone or in association with Nosema ceranae. Since this pathogenic effect contradicts the results of the experimental infections originally performed by Langridge and McGhee nearly 40 years ago, we investigated the potential linkage of this protozoan with colony decline under laboratory conditions. Nosema-free and trypanosomatid-free honey bees from three different colonies were experimentally infected with fresh C. mellificae spheroid forms (reference strain ATCC30254), with N. ceranae fresh spores and with both parasites at the same time. Replicate cages were kept at 27 °C and used to analyse survival. C. mellificae spheroid forms did not reduce significantly the survival of the worker bees (64.5% at 30 days post-infection vs. 77.8% for the uninfected bees used as controls; differences were non statistically significant) under these experimental conditions. In contrast, the cages infected with N. ceranae exhibited higher rates of mortality from the 20th day post-infection onwards, irrespective of the presence of C. mellificae, suggesting that the spheroid forms of the latter have no pathological effect on A. mellifera
Indole-3-acetic acid (IAA) producing Pseudomonas isolates inhibit seed germination and α-amylase activity in durum wheat (Triticum turgidum L.)
No full textThe role of plant-associated bacteria in plant physiology and metabolism is well documented, but little has been known about the roles played by Pseudomonas in durum wheat (Triticum turgidum L. var durum) growth and development. An in vitroexperiment was conducted to observe the effect of the inoculation of four indole-3-acetic acid (IAA)-producing Pseudomonas isolates and exogenous IAA on seed germination traits and α-amylase activity of durum wheat. The results showed inoculation with all bacterial isolates led to a decrease in the germination percent, although the extent of the depression varied with the isolate. A significant relationship between concentrations of bacterial IAA and the germination inhibition percent in durum wheat seeds by different bacteria strains was observed. The results of this assay showed the effect of bacterial isolates on α-amylase activity after six and 8 days of inoculation was significant, while effect of these isolates on α-amylase activity after two and 4 days of inoculation was not meaningful. In addition, the exogenously applied IAA displayed a concentration-dependent effect on seed germination attributes and α-amylase activity, consistent with the possibility that the inhibitory effect of bacterial inoculation on seed germination was in consequence of bacteria-produced IAA. Therefore, it may suggested that the inhibitory role of IAA in seed germination and α-amylase activity should be taken into account during the screening of IAA-producing Pseudomonas isolates for durum wheat growth promoting agents
Phenolic compounds and antioxidant activities of grape canes extracts from vineyards
No full textGrape canes are the main agro-wastes from vineyards. This work studied the antioxidant activities of the defatted methanolic extracts (ME) of canes from 11 genotypes: 5 Vitis vinifera widely known cultivars and 6 Chinese wild varieties from three species (V. amurensis, V. davidii, and V. pentagona) and the antioxidant activities of the ME’s chloroform fractions (CF), ethyl acetate fractions (EAF) and water fractions (WF). Among ME and its three fractions, EAF’s total phenolic contents (TPC) and total flavonoid contents (TFC) were the highest, at 586 mg/g of gallic acid equivalent and 320 mg/g of quercetin equivalent, respectively. The antioxidant power of the fractions/extracts was in the order EAF > ME > WF > CF, based on the DPPH radical-scavenging power and ferric-reducing antioxidant activity, while the order was EAF > CF > WF >ME based on the β-carotene-linoleic acid bleaching activity. Methanolic extracts demonstrated the strongest Fe2+-chelating activity. The antioxidant activities of the extracts/fractions generally correlated with the TPC and TFC in all assays, except with the Fe2+-chelating test. Grape canes from V. davidii had the highest TPC, TFC and antioxidant activities compared with those from other grape species. Catechin, epicatechin and trans-resveratrol were the predominant phenolic components of fractions/extracts. In light of these valuable bioactivities, grape canes from annual pruning practice considered as waste material have good commercial potential for utilization as a promising natural antioxidant in the food, pharmaceutical and cosmetic industries, given its low cost and availability in large amounts
Short communication: Emergence of a new race of leaf rust with combined virulence to Lr14a and Lr72 genes on durum wheat
No full textLeaf rust is a foliar disease caused by the fungus Puccinia triticina that may severely reduce durum wheat yield. Resistance to this pathogen is common in modern durum germplasm but is frequently based on Lr72 and Lr14a. After accounts of races with virulence to Lr14a gene in France in 2000, the present study reports the detection in 2013 for the first time of a new race with virulence to Lr14a and Lr72. The aim of this work was to characterize the virulence pattern of four Spanish isolates with virulence to Lr14a, and to discuss the consequences of this presence. Rusted leaves from cultivars ‘Don Jaime’ (Lr14a) and ‘Gallareta’ (Lr72) were collected in 2013 in the field at two Spanish sites, one in the south (near Cadiz) and another in the north (near Girona). Spores from single pustule for each cultivar and site were multiplied on susceptible cultivar ‘Don Rafael’. Then, the four isolates were inoculated on a set of 19 isogenic lines Thatcher to characterize their virulence spectrum. All isolates presented the same virulence pattern. They were virulent on both Lr14a and Lr72 and the race was named DBB/BS. This race was very similar to those reported in 2009-11, but with added virulence to Lr14a. The resistance based on Lr14a has therefore been overcome in Spain, by a new race that has likely emerged via stepwise mutation from the local predominating races. This information is important to guide breeders in their breeding programmes and gene deployment strategies