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The acorn-fed Iberian pig is known worldwide due to the quality of the resulting products commercialized after a natural and free grazing period of fattening in the dehesa agroforestry ecosystem. The quality regulation of the pig breed reserves “acorn” denomination for only those products obtained from animals exclusively fed grazing acorns and other natural resources; however, sometimes, feed supplementation of the pig’s diet is fraudulently employed to reach an earlier slaughtering weight and to increase pig stocking rate, a strategy called postre (meaning “feed supplement”). In this sense, although many studies focused on Iberian pig diet have been published, the field detection of feed use for acorn-fed pig during the last finishing stage foraging in the dehesa, a practice which clashes with the official regulation, has not been explored yet. The present study employs a volatilome analysis (gas chromatography coupled to ion mobility spectrometry) of a non-invasive biological sample (faeces) to discriminate the grazing diet of only natural resources, that acorn-fed Iberian pigs are supposed to have, from those pigs that are also supplemented with feed. The results obtained show the suitability of the methodology used and the usefulness of the information obtained from faeces samples to discriminate and detect the fraudulent use of feed for acorn-fed Iberian pig fattening: a classification success ranging between 86.4% and 100% was obtained for the two chemometric approaches evaluated. These, together with the results of discriminant models, are discussed, in addition to the importance that the methodology optimized implies for the Iberian pig sector and market, which is also introduced. This methodology could be adapted to control organic farming animals or other upstanding livestock production systems which are supposed to be fully dependent on a natural grazing diet.

Bovine tuberculosis is considered a re-emerging disease caused by different species from the Mycobacterium tuberculosis complex (MTC), important not only for the livestock sector but also for public health due to its zoonotic character. Despite the numerous efforts that have been carried out to improve the performance of the current antemortem diagnostic procedures, nowadays, they still pose several drawbacks, such as moderate to low sensitivity, highlighting the necessity to develop alternative and innovative tools to complement control and surveillance frameworks. Volatilome analysis is considered an innovative approach which has been widely employed in animal science, including animal health field and diagnosis, due to the useful and interesting information provided by volatile metabolites. Therefore, this study assesses the potential of gas chromatography coupled to ion mobility spectrometry (GC-IMS) to discriminate cattle naturally infected (field infections) by MTC from non-infected animals. Volatile organic compounds (VOCs) produced from feces were analyzed, employing the subsequent information through chemometrics. After the evaluation of variable importance for the projection of compounds, the final discriminant models achieved a robust performance in cross-validation, as well as high percentages of correct classification (>90%) and optimal data of sensitivity (91.66%) and specificity (99.99%) in external validation. The tentative identification of some VOCs revealed some coincidences with previous studies, although potential new compounds associated with the discrimination of infected and non-infected subjects were also addressed. These results provide strong evidence that a volatilome analysis of feces through GC-IMS coupled to chemometrics could become a valuable methodology to discriminate the infection by MTC in cattle. IMPORTANCE Bovine tuberculosis is endemic in many countries worldwide and poses important concerns for public health because of their

The number of representative samples to build a calibration model plays a major role in the success of chemometric models for class discrimination; therefore, knowing which samples should be used for the calibration of prediction models is essential. The aim of this work is to design a basic guideline for the training of partial least squares discriminant analysis (PLS-DA) models to classify complex samples analysed by Gas Chromatography (GC) coupled to Ion Mobility Spectrometry (IMS) using dry-cured Iberian ham as an example. The effect of the number, proportion and class of samples for training and validation and the use of two data types (spectral fingerprint or pre-selected markers) has been assessed by analysing with GC-IMS nearly 1000 dry-cured Iberian ham samples obtained from 7 different curing plants. Subsequently, these were classified with PLS-DA according to the pig’s feeding regime (acorn-fed vs. feed-fed) and it has been demonstrated that 450 out of 997 samples are enough for model training to achieve a maximum average prediction accuracy rate. Furthermore, the use of preselected GC-IMS markers provides slightly better prediction results than the use of the complete spectral fingerprint. In summary, these results represent a tentative guide for the classification of samples in an industrial setting using GC-IMS and PLS-DA. This methodology would allow authorities and producers to ensure the quality of the agri-food products put on the market as is proven in this study

Making silage allows for the preservation of liquid and fibrous by-products, and it improves feed digestibility. Feeding silage increases the digestive system volume for the subsequent fattening phase and, as it is a bulk feed, reduces the stress of pigs under restricted feeding. • Silage is a solution for the conservation and use of by-products. • Pigs will readily eat silage once they are adapted to its consumption. • It is essential to correctly balance and calculate the daily ration, especially when animals are feed restricted. • The mixing of components, which must be very well chopped and packed without leaving any air (for anaer-obic fermentation) (figure 1), is very important for the silage preparation. • For growing pigs, the feed ration can be reduced by 10-15% so that they can eat about 240-320 g of silage/ day at the beginning (young growers) and end up eating 750 g/day. One week is recommended for progres-sive adaptation of any kind of pig to the new diet.

The role of domestic pigs in the epidemiology of Mycobacterium tuberculosis complex (MTC) is considered to be limited due to the characteristics of intensive production systems. However, in southwestern Spain, Iberian pigs are usually raised under extensive management systems, sharing their habitat with other domestic and wild species, some of which may act as reservoirs of MTC. Our objective was to determine the seroprevalence, risk factors, spatial distribution and spoligotypes of MTC circulating in extensively farmed pigs in Andalusia (southern Spain), a region with a high prevalence of tuberculosis in both cattle and wild boar populations. Serum samples from 3622 extensively-raised Iberian pigs from 129 randomly selected farms were tested for antibodies against MTC using an indirect (P22) ELISA. Antibodies to MTC were detected in 82 pigs (2.3%; 95%CI: 1.8–2.8%). Seropositivity was significantly higher in sows (3.7%) than in fattening pigs (1.7%) (P = 0.0001). Herd prevalence was 24.8% (95%CI: 17.4–32.3%). Two risk factors were associated with MTC seropositivity on farms: herd size (higher seroprevalence on larger farms) (OR=1.001; 95%CI: 1.000–1.002), and the presence of neighboring goat flocks (OR = 7.345; 95%CI: 1.464–36.848). Two statistically significant spatial clusters (P < 0.001) were identified in the north-west of Andalusia. A total of 25 different MTC spoligotypes were isolated in pigs bred extensively in the study area. Based on the serological and molecular results obtained in the current study, it is possible that extensively raised Iberian pigs may act as an MTC reservoir in Mediterranean ecosystems. The high herd prevalence, as well as the identification of significant spatial clusters, indicates widespread, but not homogenous MTC circulation among extensively-managed pig farms. Risk-based surveillance and control programs should be implemented on this type of farms in Spain.

Antimony trisulfide (Sb2S3), found in nature as the mineral stibnite, has been studied under compression at room temperature from a joint experimental and theoretical perspective. X-ray diffraction and Raman scattering measurements are complemented with ab initio total-energy, lattice-dynamics, and electronic structure calculations. The continuous changes observed in the volume, lattice parameters, axial ratios, bond lengths, and Raman mode frequencies as a function of pressure can be attributed to the different compressibility along the three orthorhombic axes in different pressure ranges, which in turn are related to the different compressibility of several interatomic bond distances in different pressure ranges. The structural and vibrational properties of Sb2S3 under compression are compared and discussed in relation to isostructural Bi2S3 and Sb2Se3. No first-order phase transition has been observed in Sb2S3 up to 25 GPa, in agreement with the stability of the Pnma structure in Bi2S3 and Sb2Se3 previously reported up to 50 GPa. Our measurements and calculations do not show evidence either for a pressure-induced second-order isostructural phase transition or for an electronic topological transition in Sb2S3. © 2016 American Chemical Society.