44 research outputs found

    Effects of liquid metabolite combinations produced by Lactobacillus plantarum on growth performance, faeces characteristics, intestinal morphology and diarrhoea incidence in postweaning piglets

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    A study was carried out to investigate the effects of feeding liquid metabolite combinations produced by Lactobacillus plantarum strains on growth performance, diarrhoea incidence, faecal pH, microfloral counts, short-chain fatty acids (SCFA) and intestinal villus height and crypt depth of postweaning piglets. A total of 120 piglets (26 days old) were randomly assigned evenly into five treatment groups treated with same basal diet: (1) −ve control (free antibiotic); (2) + ve control (0.03% of chlortetracycline); (3) Com 1 (0.3% metabolite of TL1, RG11 and RI11 strains); (4) Com 2 (0.3% metabolite of TL1, RG14 and RS5 strains); (5) Com 3 (0.3% metabolite of RG11, RG14 and RI11 strains). After 5 weeks, the average daily feed intake was not significantly different (P > 0.05) among the treatments and feed conversion ratio was the highest (P < 0.05) in the −ve control group. In addition, diarrhoea incidence was reduced when piglets were fed with metabolite combinations. Faecal lactic acid bacteria (LAB) counts were significantly higher (P < 0.05) in metabolite treatment groups than in the groups without metabolites. However, the treatment of Com 2 metabolite resulted lower (P < 0.05) faecal pH and Enterobacteriaceae (ENT) than the −ve control group. In contrast, total faecal SCFA of Com 2 were significantly higher (P < 0.05) than the −ve control group. The villus height of duodenum was higher (P < 0.05) in the + ve control and Com 2 groups as compared to −ve control group. The results obtained in this study showed that feeding metabolite combinations could improve growth performance, and increase the population of gut LAB and faecal SCFA of postweaning piglets

    Incorporating field wind data to improve crop evapotranspiration parameterization in heterogeneous regions

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    Accurate parameterization of reference evapotranspiration ( ET0) is necessary for optimizing irrigation scheduling and avoiding costs associated with over-irrigation (water expense, loss of water productivity, energy costs, and pollution) or with under-irrigation (crop stress and suboptimal yields or quality). ET0 is often estimated using the FAO-56 method with meteorological data gathered over a reference surface, usually short grass. However, the density of suitable ET0 stations is often low relative to the microclimatic variability of many arid and semi-arid regions, leading to a potentially inaccurate ET0 for irrigation scheduling. In this study, we investigated multiple ET0 products from six meteorological stations, a satellite ET0 product, and integration (merger) of two stations’ data in Southern California, USA. We evaluated ET0 against lysimetric ET observations from two lysimeter systems (weighing and volumetric) and two crops (wine grapes and Jerusalem artichoke) by calculating crop ET ( ETc) using crop coefficients for the lysimetric crops with the different ET0. ETc calculated with ET0 products that incorporated field-specific wind speed had closer agreement with lysimetric ET, with RMSE reduced by 36 and 45% for grape and Jerusalem artichoke, respectively, with on-field anemometer data compared to wind data from the nearest station. The results indicate the potential importance of on-site meteorological sensors for ET0 parameterization; particularly where microclimates are highly variable and/or irrigation water is expensive or scarce

    Reference evapotranspiration in the irrigated perimeters of the state of Sergipe

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    O conhecimento da evapotranspiração de referência (ETo) é essencial no manejo de irrigação de culturas agrícolas em todo o mundo. Neste trabalho se utilizaram dados meteorológicos diários de evaporação do tanque "Classe A", temperaturas máximas e mínimas, insolação, velocidade do vento a 2 m de altura e umidade relativa do ar, referentes ao período de 1989 a 1993, coletados em quatro perímetros irrigados do Estado de Sergipe, para estimativa da ETo com base nos métodos do Tanque Classe "A", Radiação Solar, Hargreaves & Samani, Linacre e Penman-Monteith (FAO/56). Comparam-se os valores diários da ETo para a região estudada, através dos quais, quando comparados com o modelo de Penman-Monteith (FAO/56) se obtiveram os melhores desempenhos com os métodos que utilizam a radiação solar como dado de entrada no modelo. O método do Tanque Classe "A" não apresentou desempenho satisfatório em nenhum perímetro irrigado estudado. _________________________________________________________________________________________ ABSTRACT: The knowledge of reference evapotranspiration (ETo) is essential for the irrigation scheduling of crops throughout the world. This work used daily meteorological data of Class A pan evaporation, maximum and minimum air temperatures, insolation, wind speed at 2 m above surface and relative humidity from 1989 to 1993 for four irrigated perimeters of Sergipe. These data were used for estimating ETo based on the following methods: Class A pan evaporation, Solar Radiation, Hargreaves & Samani, Linacre and Penman-Monteith (FAO/56). The daily values of ETo were compared to those obtained by FAO Penman-Monteith method in order to choose the best method of estimating ETo for the region. The best performance was obtained for those models which used the solar radiation as the data input. The Class A pan evaporation method did not show favorable performance in any irrigated perimeter
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