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Oberbauer A.M.,University of California at Davis | Berry S.L.,University of California at Davis | Belanger J.M.,University of California at Davis | McGoldrick R.M.,University of California at Davis | And 2 more authors.
Journal of Dairy Science | Year: 2013

Lameness and hoof health affect dairy cows as an animal welfare issue, in decreased milk production, and in premature culling. Selection schemes for dairy cattle focus on sire contribution to milk production, with little consideration of the cow's physical structure or disease probability. On 3 commercial California dairies, 6 phenotypic binary hoof traits that contribute to lameness were recorded: white line disease, sole ulcer, other claw horn lesions, foot rot (interdigital phlegmon), foot warts (digital dermatitis), and other lesions. Monthly lactation records were collected from December 2006 to April 2009 with weekly observations of hoof lesions for lame and dry cows. In addition to hoof lesion information, data on cows (n=5,043) included parentage, birth date, freshening date, lactation number, and date of lameness diagnosis. The prevalence of hoof lesions ranged from a low of 2.2% (foot rot) to a high of 17.1% (foot warts). The farm environment increased the odds ratio depending upon the lesion. Lameness was more common in early lactation and as lactation number increased. Using a threshold model, heritabilities and repeatabilities were estimated for each binary trait. The heritability for risk varied by lesion, with the higher estimates being 0.40 (95% confidence interval: 0.20-0.67) for digital dermatitis and 0.30 (95% confidence interval: 0.08-0.63) for sole ulcer. Including terms to account for cow productivity on either a 305-d mature-equivalent basis or a per-lactation basis had minimal effect on the heritability estimates, suggesting that selection for hoof health is not correlated with response to selection for greater milk production and that improvement could be made for both traits. The genetic component lends support for further genetic studies to identify loci contributing to some of the lesion phenotypes such as foot warts or sole ulcers, 2 of the top 3 causes of lameness in dairy cattle. © 2013 American Dairy Science Association. Source

Aragon-Gastelum J.L.,San Luis Potosi Institute of Scientific Research and Technology | Flores J.,San Luis Potosi Institute of Scientific Research and Technology | Yanez-Espinosa L.,Institute Investigacion Of Zonas Deserticas | Badano E.,San Luis Potosi Institute of Scientific Research and Technology | And 2 more authors.
Flora: Morphology, Distribution, Functional Ecology of Plants | Year: 2014

The responses of desert plants to climate warming have been poorly assessed, perhaps due to the overall expectation that desert vegetation will expand as a consequence of this component of climate change. However, determining what plant species will tolerate the expected increase in temperature is a question that remains unanswered. The Chihuahuan Desert is the largest warm desert of North America, and predictive models of climate change indicate that summer temperatures in this desert will increase by 1-2°C in the next decade. This study experimentally assessed the performance of an endangered cacti species from the Chihuahuan Desert under simulated warming conditions. Hexagonal open top-chambers (OTCs) were used to simulate the effects of global warming on five-years-old individuals of the specially protected species Echinocactus platyacanthus. Temperature was 1.9°C higher in open top-chambers than in control plots. In contrast, relative humidity was 3.1% higher in control plots than in open top-chambers. E. platyacanthus showed 100% survival for 14 weeks in both OTC and control plots. However, induced warming negatively affected the photosynthetic performance of this species. Cacti located within OTCs displayed lower maximum quantum efficiency of photosystem II (Fv/Fm), effective quantum yield of photosystem II (ΦPSII), and electron transport rate (ETR) values, but higher non-photochemical quenching (NPQ) values, than cacti from control plots. This is the first study focused on the potential impact of climate warming on survival and photosynthetic performance of young individuals of a succulent species from American deserts. Induced warming negatively affected the photosynthetic performance of young E. platyacanthus, but it also increased non-photochemical quenching, a mechanism for avoiding photoinhibition. © 2014 Elsevier GmbH. Source

Villegas-Patraca R.,Institute Ecologia | MacGregor-Fors I.,Institute Ecologia | Ortiz-Martinez T.,Institute Ecologia | Ortiz-Martinez T.,National Polytechnic Institute of Mexico | And 4 more authors.
Condor | Year: 2012

Aside from the positive benefits of wind energy, wind farms often bring environmental problems such as noise production and wildlife collision. however, little is known about the effects of wind farms on the ecology of tropical landbirds. In this study, we evaluated changes in bird-community diversity, composition, and structure directly beneath wind turbines, 200 m away from turbines, and in nearby croplands and secondary forests. In general, our results show (1) a gradient of species richness, with values highest in croplands and secondary forests, intermediate values 200 m from turbines, and lowest values beneath turbines, (2) fairly similar bird abundance for all treatments, with values highest in secondary forests in autumn and lowest 200 m from turbines in autumn, (3) bird communities highly similar at each season, but communities at 0 and 200 m from turbines differed strongly in autumn and communities at the rest of the studied sites differed strongly during both spring and autumn, (4) evenness of the bird community greater in secondary forests and croplands and lower at both distances from wind turbines, and (5) the area covered by croplands outside the wind farm played an important role, often related to increases in species richness. Our results also suggest that wind farms have a greater effect on wintering migrants than on residents; however, further studies are required for such a comparison to be tested robustly. © The Cooper Ornithological Society 2012. Source

Rendon-Huerta J.A.,Programa Multidisciplinario de Posgrado en Ciencias Ambientales | Juarez-Flores B.I.,Institute Investigacion Of Zonas Deserticas | Pinos-Rodriguez J.M.,Institute Investigacion Of Zonas Deserticas | Aguirre-Rivera J.R.,Institute Investigacion Of Zonas Deserticas | Delgado-Portales R.E.,Autonomous University of San Luis Potosi
African Journal of Microbiology Research | Year: 2011

The effects of fructans of Cichorium intybus, Helianthus tuberosus and Agave angustifolia spp. tequilana were evaluated on in vitro growth of Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium lactis. Fructan concentrations were 0, 7, 14 or 21 g/L of man rogosa sharpe broth. The pH values and optic density at 600 nm (OD 600) were measured. Broths were inoculated and incubated at 35°C for 48 h. A complete randomized design was used with a 3 × 4 factorial arrangement of treatments: Fructans (C. intybus, A. angustifolia spp. tequilana, H. tuberosus) and doses (0, 7, 14 or 21 g/L). For all bacteria, pH values quadratically decreased as fructan doses increased. Contrarily, OD 600 values quadratically increased as fructan doses rose. In L. acidophilus, the pH values of the medium with fructans from C. intybus and H. tuberosus were lower and OD 600 values were higher than with A. angustifolia spp. tequilana fructans. In L. casei pH and OD 600 values were similar for all fructan sources. In B. lactis, H. tuberosus fructans induced lower pH and higher OD 600 values than C. intybus and A. angustifolia spp. tequilana fructans. Results indicated that fructans from A. angustifolia spp. tequilana, C. intybus and H. tuberosus increased growth of B. lactis, L. casei and L. acidophilus. Although bacteria had different affinities for fructans, the lowest polymerization value improved bacterial growth. © 2011 Academic Journals. Source

Pinos-Rodriguez J.M.,Institute Investigacion Of Zonas Deserticas | Garcia-Lopez J.C.,Institute Investigacion Of Zonas Deserticas | Aguirre-Rivera J.R.,Institute Investigacion Of Zonas Deserticas | Reyes-Hernandez H.,Autonomous University of San Luis Potosi
Tropical and Subtropical Agroecosystems | Year: 2013

A community mapping procedure was developed to identify and characterize communal land area used for a traditional goat production system. Participatory cartography indicated that producers have good knowledge of their territory; more than 80% of the spatial distribution and localization of the elements and shapes present in the community map agreed with the map constructed with GIS. All flocks were mainly grazed on communal rangelands where the most important native forage plants were Opuntia spp. Yucca filifera, Condalia mexicana, Dalea spp. and Euphorbia cinerasiens, and corn stover the main crop by-product supplement used during dry season. Source

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