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131.
The objective was to study the growth potential of Sahiwal calves given milk or milk replacer with or without concentrates. For this purpose, forty-eight Sahiwal calves were divided into four groups of 12 animals each with equal sex ratio. In each group, the calves were offered either milk or a milk replacer (MR) at a rate of 10% of their body weight adjusted weekly. In addition to this, calves were fed either a starter ration plus Egyptian clover hay (SR + H) or hay only (H) until the end of trial. The milk or MR was withdrawn gradually from day 56 until animals were weaned completely by day 84. Calves offered milk grew faster than those offered MR (357 ± 9 vs. 162 ± 9 g/day; p < 0.05) and displayed higher weaning weights (51.6 ± 0.8 vs. 35.2 ± 0.8 kg; p < 0.05). The calves offered SR + H grew faster (311 ± 9 vs. 208 ± 9 g/day; p < 0.05) and displayed higher weaning weights (48.7 ± 0.8 vs. 38.1 ± 0.8 kg; p < 0.05) than those fed H alone. Calves offered milk plus SR + H showed the highest growth rate and weaning weights (401 ± 13 g/day and 56.3 ± 1 kg, respectively). The lowest growth rate and weaning weights were observed in calves offered MR and H only (115 ± 13 g/day and 30.3 ± 1 kg, respectively). Calves offered the MR had higher number of scour days than those offered milk (13.5 vs. 3.3). The feeding of whole milk in combination with the starter ration and hay resulted in superior growth rates, higher weaning weights, and healthier calves than the other feeding regimens.  相似文献   
132.
Zinc (Zn) desorption is an important process to determine Zn bioavailability in calcareous soils. An experiment was performed to assess the pattern of Zn release from 10 calcareous soils of orange orchards, southern Iran and the soil properties influencing it. For Zn desorption studies, soil samples were extracted with diethylene triamine penta-acetic acid solution at pH 7.3 for periods of 0.083–48 h. Suitability of seven kinetic models was also investigated to describe Zn release from soils. Generally, Zn desorption pattern was characterized by a rapid initial desorption up to 2 h of equilibration, followed by a slower release rate. The simple Elovich and two-constant rate kinetic models described Zn release the best, so it seems that Zn desorption is probably controlled by diffusion phenomena. The values of the rate constants for the superior models were significantly correlated with some soil properties such as soil organic matter (SOM) content, cation exchange capacity (CEC), and soil pH, whereas carbonate calcium equivalent and clay content had no significant influence on Zn desorption from soils. SOM had a positive effect on the magnitude of Zn release from soils, while soil pH showed a negative effect on Zn desorption. Furthermore, the initial release rate of soil Zn is probably controlled by CEC in the studied soils. Finally, it could be concluded that SOM, CEC, and soil pH are the most important factors controlling Zn desorption from calcareous soils of orange orchards, southern Iran.

Abbreviations: Soil organic matter (SOM); Cation exchange capacity (CEC); Calcium carbonate equivalent (CCE); Zinc (Zn).  相似文献   

133.
Abstract

Nitrogen use efficiency (NUE) is low in cereals especially in wheat. Different wheat cultivars may vary in NUE due to inherited biological nitrification inhibition (BNI) potential. In this study, three wheat cultivars (Punjab-2011, ARRI-2011 and Millat-2011) were fertilized at the rate of 140?kg ha?1 with three N sources [nitrophos (NP), urea and calcium ammonium nitrate (CAN)]. The soil nitrate (NO3?)-N contents were significantly enhanced coupled with simultaneous decrease in ammonium (NH4+)-N contents in the rhizosphere of cultivar Punjab-2011, fertilized with NP; however, cultivar Millat-2011 receiving urea behaved in contrast. Wheat cultivar Punjab-2011 fertilized with NP had the highest grain yield and agronomic NUE than other treatments due to significant increase in chlorophyl contents, allometric and yield parameters. The highest net benefit was recorded from the cultivar Punjab-2011 fertilized with CAN. In conclusion, use of NP in Punjab-2011 enhanced the grain yield and agronomic NUE.  相似文献   
134.
Terminal drought stress (drought at reproductive growth stage) has been considered a severe environmental threat under changing climatic scenarios and undoubtedly inhibits sunflower production. A field study was conducted to explore the potential role of foliar applied boron (B) (0, 15, 30, 45 mg L?1) at late growth periods of sunflower in alleviating the adversities of terminal drought stress (75, 64, 53 mm DI) grown from inflorescence emergence to maturity stages. The plant water relations such as leaf relative water content (RWC), water potential (Ψw), osmotic potential (Ψs), and turgor pressure (Ψp) were increased significantly with B foliar sprays while exposed to terminal drought stress. Foliar B application considerably improved the nitrogen and B concentrations in leaf and seed tissues, and also chlorophyll a and b pigments under terminal drought stress conditions. Drought-induced proline accumulation prevented the damages caused by drought stress, nevertheless, B foliar spray increased its contents. Compared to well-watered conditions, terminal drought stress substantially declined the growth performance in terms of reduced leaf area index (LAI), crop growth rate (CGR), net assimilation rate (NAR), and total dry matter (TDM) production; however, foliar B supply (30 mg L?1) might be helpful for improving drought tolerance in sunflower with reduced growth losses.  相似文献   
135.
In 2009, 26 clinical samples (organs and oral/cloacal swabs) from a total of 24 corn snakes (Pantherophis guttatus) from a single owner were sent to our laboratory to be tested for the presence of viruses. Paramyxoviruses (PMV), adenoviruses (AdV) and reoviruses were detected by RT-PCR, PCR and virus isolation methods. Three snakes were infected with all three viruses at the same time, while two other snakes had a double infection (PMV and reo, AdV and reo) and nine other snakes had a single infection with any of the three viruses. No viruses were detected in 10 animals. All isolated reoviruses were identical to one another and to the reptilian orthoreovirus isolate 55-02 in the partial RNA dependent RNA polymerase (RDRP) gene sequence. AdV partial polymerase sequences represented four different types, one of which was first described here: most similar to SnAdV-1, while the other three were identical to known types: SnAV-1, -2 and -3. However, the detected single PMV differed distinctly from described reptile PMV and was a new type. According to partial L gene, HN gene and U gene sequences it may be the first described representative of a third squamatid PMV cluster: "group C" within the proposed reptilian PMV genus "Ferlavirus". Nucleotide identity values for the L gene of the new PMV compared to group A viruses range between 76.5 and 80.3%, and between 80.5 and 81.2% compared to group B viruses. For the HN gene, these values were similar: 78.2-80% (A) and 79.9-80.5% (B) and somewhat lower for the U gene: 72.7-75.4% (A) and 69.7-70% (B). No reports on the prevalence of concurrent viral infection in captive snake populations have been published so far. The possibility of concurrent infection with several different viruses and subsequent consequences for animal health should be kept in mind when testing reptile samples for viruses.  相似文献   
136.
137.
[目的]利用地衣评价乌鲁木齐南郊空气质量.枝状地衣对空气中的要害气体非常敏感,具有体内富集作用,近年来地衣广泛的应用在空气质量评价中.[方法]采用地衣移植方法,从乌鲁木齐南山八一林场选择亚花松萝,移植到乌鲁木齐南郊的红雁池电厂、新疆大学校园、乌鲁木齐市动物园和乌鲁木齐市人民公园等4个不同点.移植后1和3个月后别取样,应用电感耦合等离子光谱直读法对移植地衣体内的Al、Cr、Cu、Fe、Mn、Ni、Zn等7种元素含量进行测定.[结果]亚花松萝体内被测定出的重金属元素种类和含量与移植时间之间存在显著性差异.随着地衣移植时间的延长被检测出的元素种类及含量明显增加,其中Al、Cr、Cu、Mn的含量在各移植点之间有显著性差异.[结论]亚花松萝重金属含量在生物评价乌鲁木齐南郊空气污染方面具有一定的研究价值.  相似文献   
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Use of prebiotics, nondigestible dietary ingredients that beneficially affect the host by selectively stimulating the growth of and/or activating the metabolism of health‐promoting bacteria in the intestinal tract, is a novel concept in aquaculture. An 8‐week feeding experiment was conducted to investigate the effects of dietary prebiotic inulin on growth performance, intestinal microflora, body composition and hematological parameters of juvenile beluga, Huso huso. Three replicate groups of fish (initially averaging weight as group 16.14 ± 0.38 g) were fed diets containing prebiotic inulin levels ranging from 1 to 3%. The basal diet contained 3% cellulose. Fish were fed to apparent satiation and growth performance was monitored. The results of linear regression showed that there was a negative relationship between some performance indices including weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER), energy retention (ER), feed efficiency (FE), protein retention (PR), and supplementation level of inulin, which indicated that inulin is not appropriate for supplementation in the diet of beluga. At the end of trial, in both basal and inulin groups, the total count of intestinal bacteria decreased within the second 4 weeks, but the intestinal lactic acid bacteria (LAB) increased in the 1% inulin group. These changes were not, however, reflected in the survival rate of the fish, although survival was higher compared to other groups.  相似文献   
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