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Corbee RJ Tryfonidou MA Beckers IP Hazewinkel HA 《Journal of animal physiology and animal nutrition》2012,96(3):395-402
Enostosis or eosinophilic panosteitis is a common disease in young growing large-breed dogs, such as the German Shepherd, and the risk of developing the disease by 3-4 months of age is increased by a high calcium intake. The aim of the study was to investigate whether German Shepherd puppies raised on milk replacers receive more calcium and/or vitamin D than their requirements in the pre-weaning period and thus are at increased risk of developing skeletal diseases. To this end, we surveyed German Shepherd breeders in the Netherlands about the use of puppy milk replacers (PMR). The metabolizable energy, calcium, phosphorus and vitamin D content of the eight most used PMR were compared with that of bitch milk, as reported in the literature. The protein and fat content of most PMR were somewhat lower (range 24.4-33.2 g per 100 g on dmb and 18.3-37.5 g per 100 g on dmb respectively) compared with bitch milk (31.9 and 40.2 g on dmb respectively). The vitamin D content of one of the PMR samples was sevenfold the level recommended by the NRC (Nutrient Requirements of Dogs and Cats, National Academy Press, 2006) and threefold the average level of bitch milk. The clinical relevance of this high amount is questionable, as bitch milk contains mainly 25-hydroxy-vitamin D [3843 μg (96.1 IU) per 100 g on dmb] and only limited amounts of vitamin D [524 μg (13.3 IU) per 100 g on dmb], as was determined in this study. Dutch German Shepherd breeders tended to overfeed their puppies. We calculated that misguided use of PMR can increase the risk of excessive calcium, phosphorus and possibly vitamin D intake during a vulnerable period, potentially giving rise to bone and cartilage problems later in life. 相似文献
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利用甜菜夜蛾(Spodoptera exigua)围食膜多克隆抗体免疫筛选草螟(Loxostege sticticalis)中肠cDNA表达文库,得到编码肉碱-脂酰肉碱转位酶(LstiSLC25)基因的全长cDNA克隆.该cDNA克隆全长1 474 bp(GenBank登录号EU924506),开放阅读框长897 bp,编码299个氨基酸,预测分子量和等电点分别为32.1 kD和9.46.序列含有3个典型的溶质运转重复结构,具有溶质运载蛋白家族的典型特征.将该基因与pET30载体重组后,经IPTG诱导,蛋白在大肠杆菌(Escherichia coli获得了表达. 相似文献
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Major outer membrane proteins of Brucella spp.: past,present and future 总被引:16,自引:0,他引:16
The major outer membrane proteins (OMPs) of Brucella spp. were initially identified in the early 1980s and characterised as potential immunogenic and protective antigens. They were classified according to their apparent molecular mass as 36–38 kDa OMPs or group 2 porin proteins and 31–34 and 25–27 kDa OMPs which belong to the group 3 proteins. The genes encoding the group 2 porin proteins were identified in the late 1980s and consist of two genes, omp2a and omp2b, which are closely linked in the Brucella genome, and which share a great degree of identity (>85%). In the 1990s, two genes were identified coding for the group 3 proteins and were named omp25 and omp31. The predicted amino acid sequences of omp25 and omp31 share 34% identity. The recent release of the genome sequence of B. melitensis 16 M has revealed the presence of five additional gene products homologous to Omp25 and Omp31. The use of recombinant protein technology and monoclonal antibodies (MAbs) has shown that the major OMPs appear to be of little relevance as antigens in smooth (S) B. abortus or B. melitensis infections i.e. low or no protective activity in the mouse model of infection and low or no immunogenicity during host infection. However, group 3 proteins, in particular Omp31, appear as immunodominant antigen in the course of rough (R) B. ovis infection in rams and as important protective antigen in the B. ovis mouse model of infection. The major OMP genes display diversity and specific markers have been identified for Brucella species, biovars, and strains, including the recent marine mammal Brucella isolates for which new species names have been proposed. Recently, Omp25 has been shown to be involved in virulence of B. melitensis, B. abortus and B. ovis. Mutants lacking Omp25 are indeed attenuated in animal models of infection, and moreover provide levels of protection similar or better than currently used attenuated vaccine strain B. melitensis Rev.1. Therefore, these mutant strains appear interesting vaccine candidates for the future. The other group 3 proteins identified in the genome merit also further investigation related to the development of new vaccines. 相似文献
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日粮中25-OH-D3、VD3不同水平组合对肉仔鸡生长性能的影响 总被引:3,自引:0,他引:3
试验分为5个处理组,25-OH-D3(μg/kg)、VD3(IU/kg)的添加量分别为0、2760,69、0,34.5、1380,34.5、2760,69、1380,每组4个重复,每个重复10只健康艾维茵肉公雏,共200只,研究25-OH-D3和VD3不同添加水平组合对肉仔鸡生长性能的影响。结果表明,各处理组肉仔鸡生长性能均较好,而且相互之间的差异均不显著(P>0.05)。日粮中组合添加25-OH-D334.5μg/kg和VD31380 IU/kg时,肉仔鸡的生长性能最佳。 相似文献
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乳牛口服大量β-胡萝卜素对维生素D3及钙磷代谢的影响 总被引:1,自引:0,他引:1
6头健康成年荷斯坦乳牛被随机均分为2组。试验组牛第1周每头口服β-胡萝卜素23.0g,以后每周每头口服11.5g,对照组不做任何处理。试验期共8周。结果表明,试验组乳牛血清钙及无机磷水平呈下降趋势;血清维生素D3活性代谢产物25-OH-D3和1,25-(OH)2-D3均呈现明显下降;至第5周末,血液β-胡萝卜素水平最高,25-OH-D3水平下降非常明显。据此认为,乳牛对β-胡萝卜素的吸收存在一阈值,大剂量的β-胡萝卜素进入机体,可能直接干扰维生素D3的羟化,使其活性代谢产物呈下降趋势,但由于吸收阈值的存在,其对维生素D3和骨骼钙磷代谢的干扰作用可得到一定程度的减缓。 相似文献
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四密25是优质高产适应性较强的玉米品种,虽创造出吉林省东部半山区15000kg/hm2的高产记录,但产量波动(7500~15000kg/hm2)较大。为进一步研究其高产稳产的构成因素,1994-2004年,在吉林省东部半山区桦甸市5个乡镇,应用四密25分别进行了品种比较、高产攻关、覆膜种植与裸地种植、不同施肥量、施肥方法、播种方法、播种时期、不同密度及等离子体处理种子的剂量、次数、播种期、化肥利用率的试验。通过对上述各项试验的194份材料统计分析,明确了四密25构成产量模型的3个主导因素为千粒重、穗粒数、公顷穗数。根据回归分析理论,计算出产量与3个主导因素之间的模型,为今后吉林省东部半山区四密25高产稳产提供理论依据。 相似文献
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以陕北农牧交错带的荒漠化土壤为研究对象,通过多元相关分析、回归分析和因子分析,确定了荒漠化程度的土壤评判指标。结果表明,评判土地荒漠化程度时,土壤物理性质指标应选择0.25~0.05 mm砂粒含量,土壤化学性质指标应选择土壤有机质含量,并运用这两个指标建立了荒漠化程度土壤评判指标体系,即通过荒漠化土壤表层0~20 cm上述两个指标的量值来评判荒漠化程度。 相似文献