【作者】 高欣；

【导师】 安瑞永；

【作者基本信息】 河北师范大学 ， 动物学， 2008， 硕士

【摘要】 本实验配制了芽孢杆菌不同添加比例(0、0.1%、0.2%、0.4%、0.8%、1.6%)的饲料,通过养殖生长实验和生化分析实验,利用能量生态学方法研究了芽孢杆菌添加比例对西伯利亚鲟(Acipenser baeri)幼鱼摄食生长、身体营养组成、营养物质消化率、氮收支、能量收支及肠道菌群的影响。结论如下:1不同芽孢杆菌添加比例对西伯利亚鲟幼鱼的摄食率没有显著影响,而添加比例为0.2%的实验组幼鱼的相对增重率和特定增长率均达到最大值,且与其他处理组相比均达到极显著差异水平。说明芽孢杆菌对鲟鱼的摄食没有直接影响,而对生长的影响较显著。2芽孢杆菌能显著影响西伯利亚鲟幼鱼对饲料蛋白质和脂肪的消化率,其中,幼鲟对添加比例为0.2%的饲料组的蛋白质和脂肪的消化率最高,超过时反而下降。说明适量的芽孢杆菌可能促进蛋白质和脂肪在胃肠道内的消化和吸收。过量时将降低对蛋白质和脂肪的消化率。3芽孢杆菌能够显著提高西伯利亚鲟幼鱼饲料的转化率和蛋白质效率,在0～0.2%添加比例范围内,随添加比例的升高,饲料转化率和饲料蛋白效率显著升高,超过0.4%时反而下降。4芽孢杆菌添加比例为0.2%的饲料组的鱼体蛋白积累最高;而随着添加比例的升高,鱼体的蛋白积累逐渐减少而脂肪的含量逐渐升高,说明饲料中添加的芽孢杆菌高于0.4%时不再促进和提高西伯利亚鲟身体蛋白的积累,可能反而转变成对脂肪积累的促进,从而影响其生长性能。5氮收支结果显示,芽孢杆菌添加比例为0.2%的处理组2的生长氮占摄入氮的比例为所有处理组中最大,粪氮占摄入氮的比例为所有处理组中最小,而排泄氮所占比例并未达到最小,但是随着芽孢杆菌添加比例的增加呈逐渐下降趋势。说明饲料中添加适量的芽孢杆菌(添加比例为0.2%左右),可以促进西伯利亚鲟幼鱼将摄入氮更多的转化为身体蛋白和脂肪的积累,从而减少粪氮和排泄氮的排泄。这在一定程度上也反映出芽孢杆菌有减少粪氮排放改善水质的作用。6能量收支结果表明,芽孢杆菌添加比例在0.2%～0.4%范围内生长能占摄入能的比例最高(22.49%);添加比例为0.2%时芽孢杆菌显著降低了西伯利亚鲟粪能占摄入能的比例,而排泄能随着添加比例的增加呈逐渐降低的趋势。7从试验结果可以看到,试验组前肠和中肠的细菌总数分别增加了22%、15%,而后肠的细菌总数减少了33%。对肠道细菌分离及鉴定的结果表明,试验组肠道中芽孢杆菌(Bacillus spp.)得到了很好的定植,占到17.5%;动性球菌属(Planococcus spp.)、动性杆菌属(Planomicrobium spp.)的比例有所增加,分别平均增加3.4%、4.4%;气单胞菌(Aeromonas spp.)、链霉菌(Streptomyces spp.)、库克菌(Kocuria spp.)、原小单胞菌(Promicymonospora spp.)分别下降了8.4%、3.5%、5.7%、3.3%。8综合考虑,西伯利亚鲟幼鱼饲料中芽孢杆菌最适添加比例为0.2%。其对幼鱼的生长、营养物质的消化率及鱼体蛋白积累有着显著的促进作用,建议可作为鲟鱼饲料的最适添加量。但是,实验也表明其添加比例超过0.4%时各项生长指标均显著下降,其影响机理有待今后进一步通过实验研究探讨。更多还原

【Abstract】 In this experiment,six experiment diets were formulated in different Bacillus spp. levels(0,0.1%,0.2%,0.4%,0.8%,1.6%) and were fed to juvenile Acipenser baeri.The growth experiment and the biochemistry analysis experiment were conducted to investigate the effects of Bacillus spp. on feed consumption,growth,digestibility to nutrition,body composition,nitrogen budget,energy budget and the composition of the intestine bacteria in juvenile Acipenser baeri.The main results and conclusions were shown as the following:1. There were no significant differences in the feeding rates of juvenile Acipenser baeri among different Bacillus spp. accession proportion,but Specific growth rates(SGR) were the best at the accession proportion of 0.2%.It is illuminated that there is no direct effect on the feeding rates among different Bacillus spp. accession proportion but significant effect on the growth in the juvenile Acipenser baeri.2. The Bacillus spp. has significant effect on the protein digestibility in juvenile Acipenser baeri as well as the fat.The treatment which the accession proportion is 0.2% has achieved the maximum digestibility on the protein and fat in juvenile sturgeon,but it decreased when the accession proportion exceeded. This result indicates that the Bacillus spp. can promote the digestibility of protein and fat in a right amount,but decreased when excess.3. The Bacillus spp. significantly increased feed conversion efficiency(FCE) and protein efficiency ratio(PER) in juvenile Acipenser baeri which increased with the increasing of Bacillus spp. at the accession proportion of 0~0.2%,but the FCE and PER decreased when exceeded to 0.4%.4. The protein accumulation in the body of juvenile Acipenser baeri was the highest at the accession proportion of 0.2%,but the protein accumulation decreased and the fat content increased gradually with the increasing of the accession proportion of Bacillus spp.. This result indicates that it didn’t promote and increase the protein accumulation of the body any more when exceeded the accession proportion of 0.4%,but increase the fat accumulation on the contrary.As the results,it decreased the growth performance.5. The nitrogen budget results indicated that the ratio of growth nitrogen and feces nitrogen to nitrogen intake with the accession proportion of 0.2% of Bacillus spp. was the maximum and minimum among all the treatments respectively. But the ratio of the ruric nitrogen to nitrogen intake didn’t achieve the minimum,presented the tendency of decreasing gradually with the increase of accession proportion of Bacillus spp..The results indicates that it can promote the intake nitrogen convert to the accumulation of protein and fat further and decrease the ratio of feces nitrogen and ruric nitrogen on the contrary in juvenile Acipenser baeri with the suitable accession proportion of Bacillus spp. into the feeds(0.2%).The results indicated that the Bacillus spp. can decreased the dischargement of feces nitrogen and improve the water quality in a certain extent.6. The energy budget results indicated that the ratio of growth energy to intake energy achieve the maximum with the accession proportion of Bacillus spp. among 0.2%~0.4%.The treatment with the accession proportion of Bacillus spp. at 0.2% decreased the ratio of feces energy to the intake energy significantly,but the uric energy to the intake energy decreased gradually with the increased of accession proportion.7. The results showed that the total quantity of bacteria in the foregut and midgut increased 22%、15% and decreased 33% in the hindgut to the control respectively.The results of separating and authenticating the intestine bacteria showed that it can promote the quantity of probiotics significantly comparing to the control with appending suitable quantity of Bacillus spp. in the feeds,and the Bacillus spp. settled down in the intestine successfully at the proportion to the 17.5%.Probiotics of the treatment2 such as Planococcus and Planomicrobium increased 3.4%、4.4%to the control respectively;the nocuous bacterias such as Aeromonas, Streptomyces, Kocuria, Promicymonospora decreased 8.4%、3.5%、5.7%、3.3% to the control respectively.8. Taking into account synthetically,the optimum accession proportion of Bacillus spp. to the feeds is 0.2%.Considering the significant effects of Bacillus spp. on the growth performance,digestibility to the nutrition and body protein accumulation in juvenile Acipenser baeri,it is suggested that the 0.2% should be the optimum accession proportion.However,the experiment results showed that every growth index decreased when the accession proportion exceeded 0.4%,the mechanism awaits for the experiment to investigate henceforth.更多还原