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51.
山羊酸奶加工工艺研究   总被引:1,自引:0,他引:1  
山羊奶含有丰富的蛋白质、脂肪、乳糖、矿物质及多种维生素,Ca、P及某些生物活性物质(如cAMP,cGMP等)含量高于牛奶。采用响应曲面法研究了山羊酸奶的发酵温度、加糖量、球杆菌比例和接种量。结果表明:在38℃,蔗糖添加量6%,嗜热链球菌接种量1.5%,保加利亚乳杆菌接种量0.5%的条件下,山羊酸奶品质最好。  相似文献   
52.
The accuracy of ‘available’ and ‘extractable’ soil water estimates was investigated using irrigated and unirrigated beans (Vicia faba) grown in an alluvial silt loam in Canterbury, New Zealand. Available water capacity was defined as the difference between soil water contents in the root zone at the drained upper limit (DUL) and at the lower limit (LL) as estimated by laboratory procedures. Extractable water capacity was specified as the difference between field estimates of DUL and LL for the whole profile affected by roots. DUL was estimated in the laboratory by equilibrating soil cores at matric potentials at ?10, ?20 or ?30 kPa, and in the field by neutron moderation. Laboratory estimates of LL were made from soil samples equilibrated at ?1.5 MPa matric potential. In the field LL was measured by neutron moderation on plots where evaporation had apparently ceased due to drought stress.When compared at intervals down the profile laboratory estimates of DUL and LL showed poor agreement with field observations. However, the final estimates of available and extractable water capacities were similar because of compensatory inaccuracies in the laboratory estimates. Furthermore, field measurements of evapotranspiration, using neutron moderation and tensiometry, indicated that the accuracy of the available water estimates was much reduced by upward fluxes of water into the rooting zone. These fluxes resulted in water extraction to at least 1.0 m although the apparent maximum rooting depth (measured by counting roots washed from soil cores) was only 0.7 m.Particular attention was paid to the influence of subsoil textural variability, which is pronounced in such soils. Laboratory and field estimates of the LL had to be carefully matched texturally before relevant comparisons could be made. Problems associated with subsoil textural variability affected laboratory methods of DUL estimation more than field methods.  相似文献   
53.
The present study investigated the optimum dietary protein level for the maturation of adult Pangasianodon hypophthalmus broodstock. Four isocaloric diets containing 250, 300, 350 and 400 g kg?1 of protein levels were prepared and presented to triplicate groups of fish. The fish (mean weight 770 ± 17.23 g and 712 ± 23.42 g for females and males respectively) were stocked in outdoor canvas tanks (4 m × 1 m × 1 m) at a stocking density of 20 fish/tank with a male: female ratio of 1:4. The fish were fed the test diets to satiation twice daily for 6 months. Gonadosomatic index (GSI) and fecundity were similar among fish fed dietary protein levels, higher than those fed on the 250 g kg?1. Final weight, weight gain, oocyte weight were significantly highest (< 0.05) for the fish fed 350 and 400 g kg?1 dietary protein treatments. Only the 350 g kg?1 dietary protein treatment resulted in significantly best ovipositor diameter and % ripe egg. Amino acid levels were highest in the muscle followed by the oocyte and liver of fish fed 350 and 400 g kg?1 dietary protein levels. The present results suggested that a dietary protein level of 350 g kg?1 can be recommended for the development of P. hypophthalmus broodstock.  相似文献   
54.
The study estimates technical efficiency and investigates the factors affecting the technical inefficiency of cage fish farming in Peninsular Malaysia. The study employs the stochastic frontier function to estimate a production frontier and technical inefficiency model. The data were collected using standard structured questionnaires completed by sample cage fish farmers in the study area. The result reveals an estimated mean technical efficiency score of 0.79, implying that the sample fish farmers are operating 21% below the production frontier and thus, there is room for improvement. The production function involves the use of one output and four inputs, which are stocking density, feed, labour and other relevant production costs. The coefficients of all the inputs have positive signs and statistically significant impacts on the output. The output elasticity associated with stocking density is the highest (0.634), followed by feed (0.317). The null hypotheses that the technical inefficiency effects are absent from the model and that the combined exogenous variables do not influence inefficiency are strongly rejected. The individual's null hypotheses of no age effect, no experience effect, no education effect, no species effect, no extension services effect, no workshop attended effect and no diseases effect on technical inefficiency are all rejected at different levels of statistical significance.  相似文献   
55.
摘要:介绍了马来西亚2块巨草竹属天然林的4种采伐技术。采伐18个月后,发现采伐技术和竹丛的形式在新秆和秆枯损方面有很大的影响。在纳米和Betau地区的立地上没有太大的影响。结果表明:X形采伐技术由于其破坏性小和竹秆低部伐除(7.1%),因此在天然竹林的管理上值得推荐。同U形的采伐技术相比,  相似文献   
56.
Journal of Soils and Sediments - The aim of this study was to compare organic and inorganic amendments namely citric acid, ammonium nitrate, compost, and titanium dioxide nanoparticles (TiO2 NPs)...  相似文献   
57.
Fifty dogs were investigated in order to correlate the length and position of the lower oesophageal sphincter (LOS) with external measurements. Various external measurements were taken while the dogs were anaesthetised and positioned in lateral recumbency. An oesophageal tube was then introduced into the oesophagus and thoracic radiographs were taken. The 'real internal length of the oesophagus' was calculated as the length from the lower jaw incisor tooth to the position of the oesophageal tube at the costal border of the diaphragm. A highly significant linear correlation was found between this internal length and the external length from lower jaw incisor tooth to the anterior border of the head of the 10th rib. Using oesophageal manometry, the length and position of the LOS was also studied in 25 clinically normal bitches. The mean length of the LOS was found to be 4.6 +/- 0.92 cm. The position of the LOS was a mean of 4.4 +/- 1.69 cm cranial to the costal border of the diaphragm. The findings of this study indicate that the external measurements can be used to position catheters for accurate oesophageal manometry in the dog.  相似文献   
58.
ABSTRACT The incidence of Pierce's disease (PD), caused by Xylella fastidiosa, was monitored in 11 naturally infested commercial vineyards to determine the presence of an X. fastidiosa vector, Homalodisca coagulata (glassy-winged sharpshooter [GWSS]), to examine the spatial patterns of the disease and elucidate possible influences of surrounding environments. Disease incidence ranged from <1 to 65% among vineyards in 2001. Our efforts to trap or capture potential disease vectors have indicated that the GWSS is the most likely vector. Disease incidence doubled in most vineyards during the 2002 production season. Spatial patterns of symptomatic vines in 2001 and 2002, as determined by ordinary runs analysis, showed strong evidence for within- and across-row aggregation of infected vines. In most fields, they were no disease gradients observed relative to GWSS source (e.g., citrus). Within fields, however, disease incidence displayed strong spatial dependence and a high degree of anisotropy, indicating strongly aggregated patterns of disease with distinct directional orientation. The within-row (0 degrees ) and across-row (90 degrees ) orientations generally were the predominant directions of increased disease incidence, consistent with vine-to-vine spread of X. fastidiosa. We concluded that the distribution of PD in vineyards reflected the feeding pattern of vectors carrying X. fastidiosa. Based on these results, effective PD management is likely to be based on practices that reduce significant insect vector populations and remove infected vines as soon as identified and on the use of resistant cultivars.  相似文献   
59.
Heartwater was diagnosed in sheep at the Umm Banein Livestock Research Station, Blue Nile Province, Sudan.Cowdria ruminantium was isolated from sheep by subinoculation of blood into a goat. AdultAmblyomma lepidum ticks fed as nymphs on this goat transmitted heartwater to a Friesian (Bos taurus) calf. Brain stabilates from this calf, either snapfrozen into liquid nitrogen or frozen slowly in a deepfreezer at –70°C, with DMSD as cryoprotectant, were infective to cattle when inoculated subcutaneously.  相似文献   
60.
The effect of metoclopramide (0.4 mg/kg, IM) on lower oesophageal sphincter pressure (LOSP) and barrier pressure (BrP) were studied manometrically (non-perfused with strain gauge pressure transducer) in 30 dogs undergoing ovariohysterectomy. Premedication (45–50 min prior to anaesthesia) consisted of either acepromazine (0.1 mg/kg, IM) plus 1 mg/kg (IM) pethidine (ACP + P) or their combination with metoclopramide which was given 5–7 min either before or after the other drugs. Studies of continuous tracings taken for 1 min at 10 min interval during surgery have suggested that if metoclopramide is given prior to ACP + P it can restore BrP to a significantly (Unpaired “t” test) higher level than when it is given subsequently or not used at all. It seemed that if the effect of ACP+P on the LOS initiated by metoclopramide is incapable of maintaining or restoring BrP. It has also been suggested that metoclopramide is unable to maintain a significantly higher level of LOSP in anaesthetized dogs irrespective of the time of its administration. However, if it is used before ACP+P it lowers the risk of gastro-oesophageal reflux (GOR) by maintaining a better barrier pressure.  相似文献   
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