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1.
K Ashley S Wilson JR Young HP Chan S Vitou S Suon PA Windsor RD Bush 《Tropical animal health and production》2018,50(1):63-73
Forage technology has been successfully introduced into smallholder cattle systems in Cambodia as an alternative feed source to the traditional rice straw and native pastures, improving animal nutrition and reducing labour requirements of feeding cattle. Previous research has highlighted the positive impacts of forage technology including improved growth rates of cattle and household time savings. However, further research is required to understand the drivers, challenges and opportunities of forage technology for smallholder cattle households in Cambodia to facilitate widespread adoption and identify areas for further improvement. A survey of forage-growing households (n = 40) in July–September 2016 examined forage technology adoption experiences, including reasons for forage establishment, use of inputs and labour requirements of forage plot maintenance and use of forages (feeding, fattening, sale of grass or seedlings and silage). Time savings was reported as the main driver of forage adoption with household members spending approximately 1 h per day maintaining forages and feeding it to cattle. Water availability was reported as the main challenge to this activity. A small number of households also reported lack of labour, lack of fencing, competition from natural grasses, cost of irrigation and lack of experience as challenges to forage growing. Cattle fattening and sale of cut forage grass and seedlings was not found to be a widespread activity by interviewed households, with 25 and 10% of households reporting use of forages for these activities, respectively. Currently, opportunities exist for these households to better utilise forages through expansion of forage plots and cattle activities, although assistance is required to support these households in addressing current constraints, particularly availability of water, if the sustainability of this feed technology for smallholder cattle household is to be established in Cambodia. 相似文献
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"Tubules-Within-a-Tubule" Hierarchical Order of Mesoporous Molecular Sieves in MCM-41 总被引：1，自引：0，他引：1
The recently discovered mesoporous aluminosilicate MCM-41 consists of hexagonal arrays of nanometer-sized cylindrical pores. It is shown that this material can be synthesized by cooperative condensation of silicate and cylindrical cationic micelles. Careful control of the surfactant-water content and the rate of condensation of silica at high alkalinity resulted in hollow tubules 0.3 to 3 micrometers in diameter. The wall of the tubules consisted of coaxial cylindrical pores, nanometers in size, that are characteristic of those of MCM-41. The formation of this higher order structure may take place through a liquid crystal phase transformation mechanism involving an anisotropic membrane-to-tubule phase change. The hierarchical organization of this "tubules-within-a-tubule" particle texture is similar to that of the frustules of marine diatoms. 相似文献
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Triacylglycerols are the most concentrated storage form of energy for the mammalian organism. These lipids are synthesized and secreted by the liver and serve as a fuel for other tissues. This paper presents a brief review of the regulation of hepatic triacylglycerol synthesis and secretion. Particular attention will be given to the dissociation of the synthesis of triacylglycerols from that of the metabolically closely related nitrogenous phospholipids. Recent evidence is presented which suggests that triacylglycerol synthesis (and secretion) is regulated, at least partially, at the diacylglycerol branchpoint. 相似文献
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Veldhuizen EJ Tjeerdsma-van Bokhoven JL Zweijtzer C Burt SA Haagsman HP 《Journal of agricultural and food chemistry》2006,54(5):1874-1879
Carvacrol is a component of several essential oils and has been shown to exert antimicrobial activity. The structural requirements for the activity of carvacrol were determined by comparison to structurally related (nonessential oil) compounds. Removal of the aliphatic ring substituents of carvacrol slightly decreased the antimicrobial activity. The effect of the hydroxyl group of carvacrol on activity could not be determined by simply comparing it to p-cymene, because this compound is immiscible with water; therefore, 2-amino-p-cymene, the amino analogue of carvacrol, which has a similar hydrophobicity and structural characteristics, was used. 2-Amino-p-cymene had similar membrane disruption and bacterial killing characteristics as carvacrol showing that, contrary to previous reports, the hydroxyl group of carvacrol itself is not essential for the antimicrobial activity. However, the observed 3-fold lower activity for 2-amino-p-cymene as compared to carvacrol indicates special features in the antimicrobial mode of action of carvacrol due to the hydroxyl group. 相似文献
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Danlois F Zaltash S Johansson J Robertson B Haagsman HP Rollin F Ruysschaert JM Vandenbussche G 《Veterinary journal (London, England : 1997)》2003,165(1):65-72
The biochemical composition and biophysical behaviour of pulmonary surfactant samples isolated from healthy Belgian White and Blue (BWB) and Holstein Friesian (HF) calves have been investigated and compared. Interesting differences in composition have been demonstrated. In particular, a higher level of total hydrophobic surfactant-associated proteins (SP) (due to higher levels of SP-B and SP-C) is reported in HF calves compared to BWB calves. Higher levels of phosphatidylcholine (PC) and especially the disaturated form of PC were also found in HF as compared to BWB calves. No immediate effect on the surface tension properties evaluated by the pulsating bubble surfactometer was found between the surfactant samples of the two breeds under physiological conditions. However, since a high content of disaturated PC and the presence of the SP-B and SP-C are thought to be essential for the surface activity, we propose that the reported modifications could contribute to the apparently lower resistance of the BWB calves to respiratory troubles in comparison with HF calves. 相似文献
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Hepatic triacylglycerol synthesis during a period of fatty liver development in sheep 总被引：3，自引：0，他引：3
T H Herdt T Wensing H P Haagsman L M van Golde H J Breukink 《Journal of animal science》1988,66(8):1997-2013
Fatty liver was induced in six sheep by fasting and treatment with phloridzin and epinephrine. Treatment was associated with a rise in the concentration in serum and hepatic uptake of nonesterified fatty acid (NEFA) compared with pretreatment (P less than .01). At 24 h after the start of the treatment, concentrations of serum lipoprotein in each density class were not different from baseline, but all were elevated (P less than .01) by 120 h of treatment. Hepatic triacylglycerol (TG) concentration increased (P less than .01) 17-fold within the first 48 h of treatment, with no additional increase during the remaining 72 h. The activity of phosphatidate phosphohydrolase (PAP) in hepatic microsomes increased (P less than .01) fourfold over baseline by 48 h of treatment, then declined slightly by 120 h. The activities of diacylglycerol acyltransferase (DGAT) and glycerolphosphate acyltransferase (GPAT) in hepatic microsomes increased during treatment but appeared to follow a slightly different pattern from that of PAP. Activity of GPAT was not above baseline at 48 h, but was at 120 h (P less than .05); DGAT activity was increased (P less than .05) twofold at 48 h, with an apparent continued increase (P less than .01) to threefold over baseline by 120 h of treatment. Fatty liver appeared to develop during a period of rapid hepatic uptake of NEFA without a corresponding increase in serum lipoprotein concentrations. The activities of PAP, GPAT and DGAT, putative regulators of TG synthesis rate, all increased in liver microsomes during a period of high hepatic NEFA uptake, but that of PAP appeared to coincide most closely with the development of fatty liver. 相似文献
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Inamuco J Veenendaal AK Burt SA Post JA Tjeerdsma-van Bokhoven JL Haagsman HP Veldhuizen EJ 《Veterinary microbiology》2012,157(1-2):200-207
The European ban on the use of antibiotic growth promotors has increased the search for new alternatives to prevent pig intestinal microbial diseases and to stimulate growth. The addition of essential oils or components thereof, such as carvacrol, to pig feed is a promising alternative. In this report we determined the effect of sub-lethal concentrations of carvacrol on Salmonella Typhimurium. At concentrations where growth of Salmonella was not inhibited, carvacrol completely inhibited motility of the bacterium. This loss of motility was not due to the loss of the flagellum or to ATP shortage upon carvacrol treatment. Adhesion of Salmonella to IPEC-J2, porcine intestinal epithelial cells, was not affected by carvacrol but invasion was significantly reduced. In addition, the epithelial gene expression of porcine β-defensin 2, an innate immune response to Salmonella infection, was reduced when Salmonella was exposed to carvacrol. This indicates that invasion but not adhesion of Salmonella triggers the porcine β-defensin 2 expression of porcine epithelial cells. 相似文献
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CMAP27, a novel chicken cathelicidin-like antimicrobial protein 总被引：6，自引：0，他引：6
van Dijk A Veldhuizen EJ van Asten AJ Haagsman HP 《Veterinary immunology and immunopathology》2005,106(3-4):321-327
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Avian defensins 总被引：4，自引：0，他引：4
Modulation of defensin expression may be one way to improve animal health and to reduce zoonotic diseases. Defensins are small, cationic, and amphipathic cysteine-rich antibiotic peptides found in plants, insects, mammals and birds. Whereas alpha- and theta-defensins appear to be absent in birds, several beta-defensins have been isolated from avian heterophils. In addition, beta-defensins were found to be constitutively or inducibly expressed at mucosal surfaces of the respiratory, intestinal and urogenital tracts. In this review the current knowledge of the defensin repertoire of birds, their tissue-specific expression, regulation and corresponding biological functions are described. 相似文献