406 research outputs found

    TRACE ELEMENTS IN SHEEP AND GOATS REPRODUCTION: A REVIEW

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    The reproduction of small ruminants like goats and sheep managed under extensive range grazing conditions can be affected by nutrients availability and especially by the mineral content of the forages resources on the rangeland. It has been particularly demonstrated that trace elements can have equally, beneficial or detrimental effects, depending on its balance, on reproductive functions in small ruminants. Trace elements as copper, molybdenum, selenium and zinc play key role on the metabolism of carbohydrates, proteins and lipids; however, the mode of action by which these elements affect reproduction in sheep and goats are not completely understood, due to the complexity in the mode of action of the metallobiomolecules and the neuro-hormonal relationship. In this way, their absence or presence of these minerals in several organs, fluids, or tissues of the reproductive tract have allowed obtaining information on the metabolism and the role of these elements on reproduction in sheep and goats. On this regard, the objective of this document is to review the relationships and effects of some trace elements, on reproductive events in sheep and goats

    EFFECT OF SEASON ON SERUM COPPER AND ZINC CONCENTRATIONS IN CROSSBRED GOATS HAVING DIFFERENT REPRODUCTIVE STATUS UNDER SEMIARID RANGELAND CONDITIONS IN SOUTHERN MEXICO STATE

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    The effect of season (rainy: RS, and dry: DS) and reproductive status on copper (Cu) and zinc (Zn) concentrations in blood serum of crossbred goats (BW= 36.01 ± 1.59 kg) were studied under semiarid rangeland conditions in Southern Mexico State. Blood samples from 80 crossbred goats were taken each season (RS and DS). The goats were clustered into 10 different groups considering their reproductive status. Concentrations of Cu and Zn in serum were assayed using atomic absorption. Data were analyzed using a general linear model procedure for a completely randomized design and differences among means were examined using a Tukey test. Blood serum concentrations of Cu and Zn were affected by reproductive status and season (P<0.001). In relation to the season, Cu and Zn serum levels were lower in RS than DS (P<0.05). Overall, kidded goats had the highest values (P<0.01) for Cu than other animals in both seasons (RS or DS). Anestrous goats had the lowest concentrations (P<0.01) for Zn during RS, while all goats at their second or more kidding, rearing single or twins, showed the highest concentrations of Zn (P<0.001) in this season. Adult goats in Southern Mexico State showed a deficiency of Cu and Zn, especially during RS. As such, mineral supplements should be provided with respect to these elements in feeding systems for goats under semiarid rangeland conditions in order to evaluate their impact on health and reproduction

    Implementation of an extended ZINB model in the study of low levels of natural gastrointestinal nematode infections in adult sheep

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    [EN] Background: In this study, two traits related with resistance to gastrointestinal nematodes (GIN) were measured in 529 adult sheep: faecal egg count (FEC) and activity of immunoglobulin A in plasma (IgA). In dry years, FEC can be very low in semi-extensive systems, such as the one studied here, which makes identifying animals that are resistant or susceptible to infection a difficult task. A zero inflated negative binomial model (ZINB) model was used to calculate the extent of zero inflation for FEC; the model was extended to include information from the IgA responses. Results: In this dataset, 64 % of animals had zero FEC while the ZINB model suggested that 38 % of sheep had not been recently infected with GIN. Therefore 26 % of sheep were predicted to be infected animals with egg counts that were zero or below the detection limit and likely to be relatively resistant to nematode infection. IgA activities of all animals were then used to decide which of the sheep with zero egg counts had been exposed and which sheep had not been recently exposed. Animals with zero FEC and high IgA activity were considered resistant while animals with zero FEC and low IgA activity were considered as not recently infected. For the animals considered as exposed to the infection, the correlations among the studied traits were estimated, and the influence of these traits on the discrimination between unexposed and infected animals was assessed. Conclusions: The model presented here improved the detection of infected animals with zero FEC. The correlations calculated here will be useful in the development of a reliable index of GIN resistance that could be of assistance for the study of host resistance in studies based on natural infection, especially in adult sheep, and also the design of breeding programs aimed at increasing resistance to parasitesSIThis work was supported by a competitive grant from the Castilla and León regional government (Junta de Castilla y León) (Ref. LE245A12-2); the EC-funded Innovative Training Network (ITN) NematodeSystemHealth (M. A. and J. M. P., P7-KBBE-2009-3-245140); the BBSRC grant BB/L004004070/1; the Spanish “Ramón y Cajal” Programme from the Spanish Ministry of Economy and Competitiveness (B. G. G., RYC-2012-10230) and a postdoctoral Jae-Doc contract from the Consejo Superior de Investigaciones Científicas (CSIC) and co-funded by the European Social Fund (M. M. V.

    Abundancia y reproducción del pelícano pardo (Pelecanus occidentalis) en dos pequeñas bahías del Pacífico central, México

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    The abundance and reproduction of the brown pelican (Pelecanus occidentalis) was studied in two bays of the Mexican Central Pacific, Bahía de Navidad and Bahía Chamela, located in the coast of Jalisco, Mexico. The number of brown pelicans in both bays was registered from December 2007 to November 2009, as well as the number of nests, eggs and nestlings in the Cocinas Island. The superficial temperature of the water, the nutrients (NO2 -, NO3-, NH4 + y PO4 -) and the primary productivity (clorofile a) were measured on a monthly basis. The greater number of pelicans was registered from January to March, in both bays. There were a bigger number of birds in the Chamela bay, mainly in early 2009. The reproductive period of the brown pelican extended from December to July on both years. The largest number of nests was observed in March and April, with an estimate of 480 (90.7 nests/hectares) in the whole nesting season of 2008 and 1,200 (226.8 nests/hectares) in 2009. In 2008 there were an estimate 1,310 eggs and 800 nestlings, while in 2009 there were an estimate 3,348 eggs and 2,200 nestlings. Both, the highest number of birds, as well as the highest number of nests, eggs and nestlings registered in 2009 were present when the temperature of the water registered its lowest values and the primary productivity (clorofile a) and nutrients, mainly NO3 - and PO4 -, registered their highest levels. These variables have a direct effect in the concentration of a larger number of fish. La abundancia y reproducción del pelícano pardo (Pelecanus occidentalis) se estudió en dos bahías del pacífico central Mexicano, Bahía de Navidad y Bahía Chamela, ubicadas en la costa de Jalisco. De diciembre de 2007 a noviembre de 2009 se registró mensualmente el número de pelícanos pardos en ambas bahías, así como el número de nidos, huevos y pollos en la isla Cocinas. Se midió mensualmente la temperatura superficial del agua, nutrientes (NO2 -, NO3 -, NH4 + y PO4 -) y la productividad primaria (clorofila a). El mayor número de pelícanos se registró de enero a marzo, en ambas bahías. Hubo una mayor abundancia de aves en la Bahía Chamela, principalmente a principios de 2009. El período reproductivo del pelícano pardo se extendió de diciembre a julio en los dos años. El mayor número de nidos se observó en marzo y abril, con un estimado de 480 (90.7 nidos/hectárea) en toda la temporada de anidación del 2008, y de 1,200 (226.8 nidos/hectárea) en 2009. En 2008 se estimaron 1,310 huevos y 800 pollos, mientras que en 2009 se estimaron 3,348 huevos y 2,200 pollos. Tanto el número de aves, como el número de nidos, huevos y pollos registrados en 2009 fueron mayores cuando la temperatura del agua registró sus valores más bajos y la productividad primaria (clorofila a) y nutrientes, principalmente NO3 - y PO4 - más altos. Estas variables tienen un efecto directo en la concentración de un mayor número de peces

    Expression of spidroin proteins in the silk glands of golden orb-weaver spiders.

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    The expression of spidroins in the major ampullate, minor ampullate, flagelliform, and tubuliform silk glands of Trichonephila clavipes spiders was analyzed using proteomics analysis techniques. Spidroin peptides were identified and assigned to different gene products based on sequence concurrence when compared with the whole genome of the spider. It was found that only a relatively low proportion of the spidroin genes are expressed as proteins in any of the studied glands. In addition, the expression of spidroin genes in different glands presents a wide range of patterns, with some spidroins being found in a single gland exclusively, while others appear in the content of several glands. The combination of precise genomics, proteomics, microstructural, and mechanical data provides new insights both on the design principles of these materials and how these principles might be translated for the production of high-performance bioinspired artificial fibers.Ministerio de Innovación, Cultura y Deportes(Spain), Grant/Award Numbers: PGC2018‐097019‐B‐I00, PID2020‐116403RB‐I00;Instituto de Salud Carlos III,Grant/Award Number: CB16/11/00277;Comunidad de Madrid, Grant/Award Numbers:NEUROCENTRO‐B2017/BMD‐3760,Tec4Bio‐CM/P2018/NMT‐4443 Spiders were reared by Oscar Campos (Reptilmadrid S.L., Spain). The artwork was made by Carmen Calvo. This study was funded by Comunidad de Madrid (Spain) through grants NEUROCENTRO‐ B2017/BMD‐3760 and Tec4Bio‐CM/P2018/NMT‐4443. This study was also supported by Spanish Ministerio de Innovación, Cultura y Deportes (PGC2018‐097019‐B‐I00 and PID2020‐116403RB‐I00), and Instituto de Salud Carlos III (CIBER de Enfermedades Cardiovasculares (CB16/11/00277); Plataforma de Recursos Biomoleculares PRB3 (ProteoRed; PT17/0019/0003)). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV‐2015‐0505).S

    Ultrahigh-energy neutrino follow-up of Gravitational Wave events GW150914 and GW151226 with the Pierre Auger Observatory

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    On September 14, 2015 the Advanced LIGO detectors observed their first gravitational-wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events were inferred to have arisen from the merger of black holes in binary systems. Such a system may emit neutrinos if there are magnetic fields and disk debris remaining from the formation of the two black holes. With the surface detector array of the Pierre Auger Observatory we can search for neutrinos with energy above 100 PeV from point-like sources across the sky with equatorial declination from about -65 deg. to +60 deg., and in particular from a fraction of the 90% confidence-level (CL) inferred positions in the sky of GW150914 and GW151226. A targeted search for highly-inclined extensive air showers, produced either by interactions of downward-going neutrinos of all flavors in the atmosphere or by the decays of tau leptons originating from tau-neutrino interactions in the Earth's crust (Earth-skimming neutrinos), yielded no candidates in the Auger data collected within ±500\pm 500 s around or 1 day after the coordinated universal time (UTC) of GW150914 and GW151226, as well as in the same search periods relative to the UTC time of the GW candidate event LVT151012. From the non-observation we constrain the amount of energy radiated in ultrahigh-energy neutrinos from such remarkable events.Comment: Published version. Added journal reference and DOI. Added Report Numbe

    Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory

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    We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to 8080^\circ and energies in excess of 4 EeV (4×10184 \times 10^{18} eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. Both analyses are complementary since the angular power spectrum achieves a better performance in identifying large-scale patterns while the needlet wavelet analysis, considering the parameters used in this work, presents a higher efficiency in detecting smaller-scale anisotropies, potentially providing directional information on any observed anisotropies. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. The corresponding pp-values obtained after accounting for searches blindly performed at several angular scales, are 1.3×1051.3 \times 10^{-5} in the case of the angular power spectrum, and 2.5×1032.5 \times 10^{-3} in the case of the needlet analysis. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales.Comment: Published version. Added journal reference and DOI. Added Report Numbe
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