The influence of soil factors on the growth of a grass/clover sward on a restored opencast site in Northumberland, UK     

R. CHAPMAN  A. YOUNGER  R. DAVIES 《Grass and Forage Science》1994,49(4):447-457

The growth of grass and clover components in mixed swards on a site restored after opencast coal mining and an undisturbed control site were compared. Soil nitrogen supply was reduced at the restored site. This inhibited grass growth but was beneficial for the clover component.
Growth at the restored site was also inhibited by a compacted subsoil, which reduced available soil water content and impeded access to available soil water. This inhibited crop production from the middle of the second silage crop onwards. In 1989 this was associated with the soil at the restored site reaching permanent wilting point at 40cm. In 1990 this effect was associated with the restored site soil reaching permanent wilting point at 70cm. These drought effects reduced clover growing point population and stolon mass. Grass tiller populations were unaffected.  相似文献   

Probiotic applications for rainbow trout (Oncorhynchus mykiss Walbaum) II. Effects on growth performance,feed utilization,intestinal microbiota and related health criteria postantibiotic treatment     

D.L. MERRIFIELD  G. BRADLEY  R.T.M. BAKER  S.J. DAVIES 《Aquaculture Nutrition》2010,16(5):496-503

The effect of dietary probiotics (Bacillus subtilis, Bacillus licheniformis and Enterococcus faecium) was assessed on rainbow trout (Oncorhynchus mykiss Walbaum) previously treated with oxolinic acid. After feeding on supplemented diets for 10 weeks growth performance, feed utilization, gastrointestinal colonization and health status were assessed. B. subtilis + B. licheniformis fed fish displayed a significant improvement of feed conversation ration (FCR), specific growth rate (SGR) and protein efficiency ratio (PER). High levels of probiotic species were observed in the posterior gastrointestinal tract as transient digesta associated populations and potentially resident mucosal populations. Levels of Bacillus spp. reached log 3.74 CFU g^?1 on the mucosal epithelium and log 7.41 CFU g^?1 in the digesta of fish fed diets supplemented with B. subtilis and B. licheniformis. Enterococci levels reached log 2.84 CFU g^?1 on the mucosa and log 7.78 CFU g^?1 in the digesta of fish fed E. faecium supplemented diets. Feeding trout the Bacillus probionts alone or synergistically with E. faecium resulted in elevated leucocyte levels. The results of the current study demonstrate a potential role of probiotics for stabilizing/reinforcing the gastrointestinal microbiota after antibiotic treatment. This could reinvigorate the intestinal defensive barrier mechanism and provide protection against secondary potential pathogens.  相似文献   

Assessment of the effects of vegetative and lyophilized Pediococcus acidilactici on growth,feed utilization,intestinal colonization and health parameters of rainbow trout (Oncorhynchus mykiss Walbaum)     

D.L. MERRIFIELD  G. BRADLEY  G.M. HARPER  R.T.M. BAKER  C.B. MUNN  S.J. DAVIES 《Aquaculture Nutrition》2011,17(1):73-79

A study was conducted to assess the probiotic effect of different dietary forms of Pediococcus acidilactici on rainbow trout (Oncorhynchus mykiss Walbaum). Growth performance, feed utilization, intestinal colonization and basic health status were investigated after a 10 week feeding trial. Fish were fed either vegetative (Veg) or lyophilized (Lyo) cells incorporated into a basal diet at either 10⁷ (Lo) or 10⁸ (Hi) CFU g^?1. P. acidilactici temporarily colonized the digestive tract (as both epithelium associated and transient populations) in all probiotic groups during supplemented feeding. Scanning electron microscopy confirmed the presence of localized colonization of P. acidilactici‐like cells between intestinal folds of the probiotic fed fish. Compared to the control group, no significant improvements in growth performance, feed utilization or carcass composition were observed in the probiotic fed fish (P > 0.05). However, a significant reduction of condition factor (K) was evident in fish fed the lyophilized diets. Increased leucocyte levels were observed in fish fed the low level vegetative P. acidilactici supplemented diet yet leucocyte types were not affected. The study demonstrates some potential for the application of P. acidilactici with rainbow trout but further research is required to optimize applications.  相似文献   

Reducing the environmental footprint of food and farming with Agriculture Green Development     

William J. DAVIES  Jianbo SHEN 《农业科学与工程前沿(英文版)》2020,7(1):1-4

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Methanol precipitation of influenza virus     

MOYER AW  SHARPLESS GR  DAVIES MC  WINFIELD K  COX HR 《Science (New York, N.Y.)》1950,112(2912):459-460

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