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Entrevista a Massimo De Marchi
No full textMassimo De Marchi es profesor investigador de Geografía y Política Ambiental en laUniversitá degli Studi di Padova (Italia), es experto en procesos participativos y gestión delos conflictos ambientales, políticas territoriales y ambientales, desarrollo local sostenible yturismo sostenible. Consultor científico de Agenda 21 Consulting desde 1998 y del Centro deEstudios VAS, Italia desde 2006. Enseñó Geografía Social, Geografía del Ambiente y del Paisaje,Geografía Humana, Laboratorio de Geografía Social en la Universidad de Padova y Métodosde Evaluación Ambiental, Métodos Participativos y Gestión de los Conflictos Ambientalesen la Universidad de Trento. Es el responsable del Programa Erasmus con las universidadesde Praga, Sofia y Wroclaw
Mid-infrared spectroscopy for an accurate prediction of immunoglobulins G concentration in bovine colostrum
No full textMid-infrared spectroscopy for a rapid assessment of immunoglobulins G level in bovine colostrum
No full textThe concentration of immunoglobulins G (IgG, g/l) defines colostrum quality in cattle. By convention, colostrum
with IgG<50 g/l is not recommended for calves feeding in the first h of life due to insufficient antibodies level. On
average, 15% of cows produce colostrum of unacceptable quality in dairy farms, exposing the calf to greater risk of
mortality and morbidity and impairing the future heifer’s performance. In this study, first colostrum samples (521
Holstein cows) were collected between 2019 and 2020 in 9 farms within 6 h from calving. Each sample was aliquoted
for IgG and protein content determination via gold standard, i.e. radial immunodiffusion and Kjeldahl, respectively,
and for prediction of total protein content via mid-infrared spectroscopy (MIR) using the prediction model developed
for mature milk. Before MIR analysis, colostrum samples were diluted in pure water (1:1) to reduce matrix density
and avoid clogging issues. We demonstrated that MIR-predicted protein content was significantly correlated with both
IgG (r=0.87) and protein content (r=0.97) measured with gold standard. Moreover, receiving operating characteristic
analysis (ROC) showed that MIR-predicted protein content was able to accurately identify low- from high-quality
colostrum samples regardless of the IgG threshold considered (50, 70, or 90 g/l). In parallel, we evaluated the
discriminant ability of colostral refractive index (BRIX), whose performance were similar to those of MIR-predicted
protein content. The area under the ROC curve was excellent, being 0.85 for MIR-predicted protein content and 0.83
for BRIX when IgG threshold was set at 50 g/l. The cut-off identified for MIR-predicted protein content was 13.08,
13.28, and 14.64% for IgG threshold at 50, 70, and 90 g/l, respectively. Findings do suggest that milk labs equipped
with MIR devices may offer an indirect quality evaluation of bovine colostrum for screening purposes and to support
farmers’ decision making. Finally, our results are of interest for industries that use bovine colostrum as an ingredient
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Genetic and Non-Genetic Variation of Milk Total Antioxidant Activity Predicted from Mid-Infrared Spectra in Holstein Cows
Full text linkFood antioxidants enhance products shelf life and stability during technological treatments through the maintenance of their physical and chemical properties. Moreover, they are endowed with several positive effects on human health, including cell membranes preservation, enzyme functionality, and DNA integrity. Milk has been described in relation to a wide array of fat soluble and water-soluble antioxidant compounds, in particular vitamin A, C, and E, lactoferrin and peptides derived from casein and whey proteins. The total antioxidant activity (TAA) of milk is a novel and scarcely explored trait, defined as the sum of antioxidant contributions of the aforementioned compounds. On this background, the aims of the present study were to investigate the variability of milk TAA on a large scale exploiting predictions obtained through mid-infrared (MIR) spectroscopy and to estimate genetic parameters of this trait in Holstein cows. Individual milk samples were collected between January 2011 and December 2018 during the routine milk recording procedure. Samples were analysed for gross composition through MIR spectroscopy and MIR spectra were stored. Milk TAA was then predicted (pTAA) from the stored milk MIR spectra (111,653 test-day records of 9519 cows in 344 herds) using the previously developed prediction model; considering the prediction accuracy, pTAA might be considered a proxy of the TAA determined through the reference method. Overall, pTAA averaged 7.16 mmoL/L of Trolox equivalents, showed a nadir around 40 days after calving and increased thereafter, following a linear trend up to the end of lactation. The lowest pTAA was observed in milk sampled from June to September. Milk pTAA was heritable (0.401 ± 0.015) and genetically associated to fat yield (0.366 ± 0.049), crude protein (CP) yield (0.238 ± 0.052), fat percentage (0.616 ± 0.022) and CP percentage (0.754 ± 0.015). The official selection index of Italian Holstein put the 49% of the emphasis on fat and protein yield and percentage; therefore, it derives that an indirect favourable selection for milk pTAA should be already in progress in Italian Holstein population
Genetic aspects of immunoglobulins G concentration measured with gold standard and predicted from infrared spectra in bovine colostrum
Full text linkThe concentration of immunoglobulins G (IgG) is the criterion usually adopted to classify the quality of the colostrum adminis-tered to calves. Although the reference analysis of IgG (g/L) is time-consuming and expensive, no studies have evaluated the ability of infrared spectroscopy to predict colostrum IgG concentration so far. In this study, colostrum was collected on 693 Holsteins within 6 h after calving following a specific protocol. Samples were analysed through the reference analysis (radial immunodiffusion), which was carried out according to the manufacturer’s instructions (Triple J Farm, Bellingham, US) after dilution of colostrum (1:5 v/v) in pure water. Near-infrared spectra (400–2500 nm) were collected on all samples using the DS2500 (Foss, Hillerød, Denmark). After spectra quality editing, the final dataset accounted for 685 samples. The calibration set included 195 samples representative of the 9 herds and cows from parity 1 to 6, and the best prediction model for IgG (RMSE =14.2 g/L; R2 = 0.84) was reached through 20-fold cross-validation and multiplicative scatter correction and second derivative as mathematical treatment. Finally, IgG was predicted in the validation set which accounted for the remaining 490 samples (RMSE =19.4 g/L; R2 = 0.73). Variance and covariance components were estimated for both reference and predicted IgG (validation set) using a linear model which included the fixed effects of parity (5 levels: 1, 2, 3, 4, and 5 + 6), the season of calving (4 levels), year of calving (2 levels), and herd (9 levels), and the random effects of additive genetic animal (6714 individuals in the pedigree) and the residual. Means (coefficient of genetic variation) of reference and predicted IgG were 92.4 g/L (14.8%) and 90.5 g/L (15.1%), respectively. Heritabilities of IgG were 0.18 ± 0.15 (reference) and 0.21 ± 0.15 (predicted). The phenotypic correlation between the two traits was positive and strong (0.86 ± 0.01), as well as the genetic correlation (0.99 ± 0.11). Overall, results indicated that IgG can be predicted from colostrum spectra with moderate accuracy and the genetic correlation between the reference and predicted IgG is close to 1. Therefore, IgG predictions can be potentially exploited as phenotypes to improve the IgG content of bovine colostrum, leading to potential practical positive consequences on calf health
Application of a handheld near-infrared spectrometer to predict gelatinized starch, fiber fractions, and mineral content of ground and intact extruded dry dog food
Full text linkThe aim of the present study was to investigate the ability of a handheld near-infrared spectrometer to predict total and gelatinized starch, insoluble fibrous fractions, and mineral content inextruded dry dog food. Intact and ground samples were compared to determine if the homogenization could improve the prediction performance of the instrument. Reference analyses were performed on 81 samples for starch and 99 for neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergentlignin (ADL), and minerals, and reflectance infrared spectra (740 to 1070 nm) were recorded with aSCiOTMnear-infrared (NIR) spectrometer. Prediction models were developed using modified partial least squares regression and both internal (leave-one-out cross-validation) and external validation.The best prediction models in cross-validation using ground samples were obtained for gelatinized starch (residual predictive deviation, RPD = 2.54) and total starch (RPD = 2.33), and S (RPD = 1.92), while the best using intact samples were obtained for gelatinized starch (RPD = 2.45), total starch (RPD = 2.08), and K (RPD = 1.98). Through external validation, the best statistics were obtained for gelatinized starch, with an RPD of 2.55 and 2.03 in ground and intact samples, respectively. Overall, there was no difference in prediction models accuracy using ground or intact samples. In conclusion, the miniaturized NIR instrument offers the potential for screening purposes only for total and gelatinized starch, S, and K, whereas the results do not support its applicability for the other traits
Genetic aspects of colostrum quality traits including immunoglobulin G in Holstein cows
Full text linkImmunoglobulins G (IgG), A (IgA), and M (IgM) account for 80% of total proteins in bovine colostrum and are important for the passive transfer of antibodies from the dam to the calf. The practical difficulties of samples collection and the high cost of gold standard analysis have so far hampered the estimation of genetic parameters of both bovine colostrum and mature milk IgG, IgA, and IgM concentrations (g/L). In the present study, 672 colostrum samples from the same number of Holstein cows were collected within 6 h after calving. The concentration of IgG, IgA, and IgM was determined through radial immunodiffusion. The pedigree included 6,714 animals, i.e., cows with phenotypes and up to 6 generations of ancestors. Linear models were used to estimate
variance and covariance components through univariate and bivariate analyses, respectively. The model included the random animal additive genetic effect and the fixed effects of parity (5 levels: 1, 2, 3, 4, and ≥5), season of calving (4 levels), year of calving (2 levels), and herd (9 levels). Colostrum IgG, IgA, and IgM averaged 93.24, 4.89, and 5.16 g/L, respectively, and were normally distributed. Heritabilities (±standard error) of IgG, IgA, and IgM were 0.14 ± 0.14, 0.33 ± 0.16, and 0.19 ± 0.14, with coefficients of genetic variation of 13.1, 30.8, and 19.7%, respectively. The IgG correlated phenotypically with IgA (0.52 ± 0.04) and IgM (0.59 ± 0.03), and IgA correlated with IgM (0.48 ± 0.04). Overall, genetic correlations were weak (<0.10) except for the association between IgG and IgA (0.37 ± 0.41). Results agreed with the literature and highlighted that the most important colostrum quality trait, i.e., the IgG, tended to be the least heritable Ig. Further efforts will allow to improve data size and variability and will be focused on coupling Ig data with other information to estimate the association between Ig of the colostrum administered to the calf and health and productivity in the subsequent lactations
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