140 research outputs found

    Finishing lambs using an integral feed under a restricted-feeding program in an intensive production system in Northern Mexico

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    The objective of this study was to compare the productive performance of finishing lambs using an integral diet under a restricted-feeding program. Ten Dorper lambs were assigned to two homogenous groups according to live weight and age under a complete randomised block design. Group 1 was fed a traditional diet commonly used by the producer and group 2 was fed an integral feed restricted to 75% of dry matter requirement of lambs. The evaluated variables were: dry matter intake, initial and final live weight, daily weight gain, feed efficiency and body growth expressed in height, body length, thoracic diameter, cane length and cane width. A partial cost analysis was carried out to evaluate the economic viability. Lambs fed with the integral feed had better feed efficiency, higher dry matter intake, daily weight gain, height, body length and thoracic diameter when compared with the lambs fed the traditional diet. The use of an integral feed under a restricted-feeding program reduced the cost of finishing lambs by 2.46 dollars per head and finishing length by 120 days. Overall, providing an integral feed under a restricted-feeding program is a viable alternative for improving finishing lambs under intensive conditions in the Northern Mexico

    Early Science with the Large Millimeter Telescope: observations of dust continuum and CO emission lines of cluster-lensed submillimetre galaxies at z=2.0-4.7

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    We present Early Science observations with the Large Millimeter Telescope, AzTEC 1.1mm continuum images and wide bandwidth spectra (73-111GHz) acquired with the Redshift Search Receiver, towards four bright lensed submillimetre galaxies identified through the Herschel Lensing Survey-snapshot and the Submillimetre Common-User Bolometer Array-2 Cluster Snapshot Survey. This pilot project studies the star formation history and the physical properties of the molecular gas and dust content of the highest redshift galaxies identified through the benefits of gravitational magnification. We robustly detect dust continuum emission for the full sample and CO emission lines for three of the targets. We find that one source shows spectroscopic multiplicity and is a blend of three galaxies at different redshifts (z=2.040, 3.252, and 4.680), reminiscent of previous high-resolution imaging follow-up of unlensed submillimetre galaxies, but with a completely different search method, that confirm recent theoretical predictions of physically unassociated blended galaxies. Identifying the detected lines as 12CO (Jup=2-5) we derive spectroscopic redshifts, molecular gas masses, and dust masses from the continuum emission. The mean H2 gas mass of the full sample is (2.0±0.2)×1011 M⊙/μ, and the mean dust mass is (2.0±0.2)×109 M⊙/μ, where μ≈2-5 is the expected lens amplification. Using these independent estimations we infer a gas-to-dust ratio of δGDR≈55-75, in agreement with other measurements of submillimetre galaxies. Our magnified high-luminosity galaxies fall on the same locus as other high-redshift submillimetre galaxies, extending the LCOL^{\prime }_{\rm CO}-LFIR correlation observed for local luminous and ultraluminous infrared galaxies to higher far-infrared and CO luminositie

    A horizon scan exercise for aquatic invasive alien species in Iberian inland waters

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    As the number of introduced species keeps increasing unabatedly, identifying and prioritising current and potential Invasive Alien Species (IAS) has become essential to manage them. Horizon Scanning (HS), defined as an exploration of potential threats, is considered a fundamental component of IAS management. By combining scientific knowledge on taxa with expert opinion, we identified the most relevant aquatic IAS in the Iberian Peninsula, i.e., those with the greatest geographic extent (or probability of introduction), severe ecological, economic and human health impacts, greatest difficulty and acceptability of management. We highlighted the 126 most relevant IAS already present in Iberian inland waters (i.e., Concern list) and 89 with a high probability of being introduced in the near future (i.e., Alert list), of which 24 and 10 IAS, respectively, were considered as a management priority after receiving the highest scores in the expert assessment (i.e., top-ranked IAS). In both lists, aquatic IAS belonging to the four thematic groups (plants, freshwater invertebrates, estuarine invertebrates, and vertebrates) were identified as having been introduced through various pathways from different regions of the world and classified according to their main functional feeding groups. Also, the latest update of the list of IAS of Union concern pursuant to Regulation (EU) No 1143/2014 includes only 12 top-ranked IAS identified for the Iberian Peninsula, while the national lists incorporate the vast majority of them. This fact underlines the great importance of taxa prioritisation exercises at biogeographical scales as a step prior to risk analyses and their inclusion in national lists. This HS provides a robust assessment and a cost-effective strategy for decision-makers and stakeholders to prioritise the use of limited resources for IAS prevention and management. Although applied at a transnational level in a European biodiversity hotspot, this approach is designed for potential application at any geographical or administrative scale, including the continental one

    LISTA NEGRA Y LISTA DE ALERTA DE ESPECIES EXÓTICAS INVASORAS ACUÁTICAS DE LA PENÍNSULA IBÉRICA - Ejercicio de exploración del horizonte transnacional centrado en las especies exóticas invasoras acuáticas de alto riesgo para las aguas interiores ibéricas.

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    Un objetivo importante de LIFE INVASAQUA es desarrollar herramientas que mejoren la gestión y sean más eficientes en el marco de Alerta Temprana y Respuesta Rápida (EWRR) para las Especies Exóticas Invasoras (EEI) en la Península Ibérica. La exploración del horizonte para las EEI de alto riesgo es básica para aplicar medidas que reduzcan las nuevas invasiones y para centrar los esfuerzos en las especies ya registradas. Desarrollamos un ejercicio transnacional de exploración del horizonte centrado en las aguas interiores de España y Portugal con el fin de proporcionar una lista negra de las EEI acuáticas actualmente establecidas y una lista de alerta de las EEI acuáticas potenciales que pueden suponer una amenaza para los ecosistemas acuáticos y los sectores socioeconómicos en el futuro. Para la exploración del horizonte seguimos un enfoque estructurado de 5 pasos que combinaba las pruebas existentes sobre las EEI con una puntuación de expertos de los taxones priorizados. En la lista negra final se priorizaron 126 EEI, que representan el 41,2% de los taxones exóticos registrados en las aguas continentales ibéricas. Las 24 primeras especies tenían un riesgo de impacto muy alto porque obtuvieron los valores máximos en el proceso de puntuación de la evaluación de riesgos. Además, la lista de alerta incluía 89 EEI con un riesgo significativo de invasión en la Península Ibérica en el futuro, estando 11 taxones en cabeza con un riesgo muy alto de invasión
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