【作者】 林小植；

【导师】 谢小军；

【作者基本信息】 西南大学 ， 水生生物学， 2009， 博士

【摘要】 本研究以我国特有经济鱼类中华倒刺鲃（Spinibarbus sinensis）幼鱼为实验对象,在27.5℃下,进行了两个系列的实验。实验一以鱼粉为蛋白质源,配制蛋白质水平分别为20.5%、26.5%、34.2%、41.0%、49.9%和55.9%的饲料喂养中华倒刺鲃10周,检验饲料蛋白质水平对其生长的影响,探讨该种鱼的最适蛋白质水平;实验二以各蛋白质水平饲料喂养中华倒刺鲃10周,测定不同蛋白质水平条件下该种鱼的标准代谢率及特殊动力作用;综合两个系列的实验资料,建立各饲料蛋白质水平处理的氮收支和能量收支方程,探讨饲料蛋白质影响该种鱼生长的营养能量学机理。本研究取得的主要结果如下:1.随饲料蛋白质水平增高,干物质摄食率(FI_dm)和能量摄食率（FI_e）均呈先显著降低,然后略有上升的趋势,20.5%组的FI_dm和FI_e均最大,分别为16.07 g kg^-1d^-1和0.25 MJ kg^-1d^-1;41.0%组的FI_dm和FI_e均最小,分别为13.55 g kg^-1d^-1和0.21 MJ kg^-1d^-1。随饲料蛋白质水平由20.5%增加至55.9%,饲料表观消化率从73.12%降低至55.02%。饲料蛋白质消化率在各组间差异不显著。2.随饲料蛋白质水平增高,体重特定生长率（SGR_w）先显著升高,达到一平台后不再明显变化,当饲料蛋白质水平由20.5%升至41.0%,SGRw由0.60%d^-1升至0.97%d^-1;当饲料蛋白质水平继续升高至55.9%,SGRw值为0.96%d^-1。随饲料蛋白质水平从20.5%升高至55.9%,饲料效率（FE）呈先显著升高,达到一平台后略有降低的趋势;蛋白质效率（PER）由178.23%降至116.60%;蛋白质累积率（PPV）由23.92%降至18.62%。3.各饲料处理鱼体的灰分含量无显著差异（p>0.05）。随饲料蛋白质水平增高,鱼体的蛋白质和水分含量显著增高（p<0.05）,而鱼体的脂肪含量和能量密度显著降低（p<0.05）。经相关性分析发现饲料蛋白质水平与鱼体蛋白质含量呈显著的正相关关系（r=0.678,p<0.01）,而与鱼体脂肪含量和能量密度均呈显著的负相关关系（r=-0.880,p<0.01;r=-0.828,p<0.01）。4.在27.5℃下,鱼体标准代谢率范围为106.8-109.1mgO₂ kg^-1h^-1,各组间的标准代谢率差异不显著。各饲料处理组的SDA总耗能量（SDAE）均随摄食能增加而显著增高,其中41.0%组的SDAE随摄食能增加而增高的速率最高（9.1%）。各组的SDAE与摄食能（C）关系如下:20.5%组:SDA_E=33.630+0.047 C （n=13,r=0.834,p<0.05）26.5%组:SDA_E=33.843+0.046 C （n=14,r=0.915,p<0.05）34.2%组:SDA_E=35.893+0.061 C （n=13,r=0.963,p<0.05）41.0%组:SDA_E=37.203+0.091 C （n=13,r=0.971,p<0.05）49.9%组:SDA_E=32.485+0.066 C （n=14,r=0.896,p<0.05）55.9%组:SDA_E=35.373+0.063 C （n=14,r=0.809,p<0.05）5.饲料蛋白质水平对SDA系数、SDA峰值、峰值比率和SDA时间均有显著影响（p<0.05）。41.0%组的SDA系数、SDA峰值和峰值比率均显著高于其余各组（p<0.05）,34.2%、49.9%和55.8%组间的SDA系数、SDA峰值、峰值比率均无显著差异,均高于20.5%和26.5%组。6.41.0%组的生长氮（GN%）显著高于其余各组,而排泄氮（UN%）低于其余各组。排粪氮（FN%）在各组间无显著差异。平均氮收支方程为100C_N=13.48F_N+64.77U_N+21.75G_NN。以饲料蛋白质水平为控制变量,对G_N%和SGR_w进行偏相关分析表明,两者存在显著的正相关关系（r=0.795,p<0.01）;G_N%与PER之间也存在显著的正相关关系（r=0.862,p<0.01）。7.当饲料蛋白质水平由20.5%增加至34.2%时,生长能（G%）由26.15%增加至27.56%;当饲料蛋白质水平高于41.0%后,G%随饲料蛋白质水平增高而显著降低（p<0.05）。随饲料蛋白质水平从20.5%增高至55.9%,代谢能（R%）由61.43%降至56.94%（p<0.05）;相反地,排粪能（F%）由8.24%增高至10.89%,排泄能（U%）由4.19%增高至9.41%。各组的能量收支方程如下: 20.5%组:100 C=26.15 G+61.43 R+8.24 F+4.19 U 26.5%组:100 C=26.85 G+59.59 R+8.33 F+5.22 U 34.2%组:100 C:27.56 G+58.08 R+8.00 F+6.37 U 41.0%组:100 C=27.10 G+58.51 R+8.48 F+5.91 U 49.9%组:100 C=24.40 G+57.10 R+10.37F+8.13 U55.9%组:100 C=23.02 G+56.94 R+10.89 F+9.41 U平均能量收支方程为100 C=25.85 G+58.61 R+9.05 F+6.54 U平均生长能和代谢能占同化能（A）的收支方程为100 A=30.57 G+69.43 R。通过讨论本研究提出以下结论:1.在水温为27.5℃,以白鱼粉为蛋白质源,饲料含能量为15.71 MJkg^-1时,中华倒刺鲃幼鱼的最适蛋白质水平范围为39.6%-42.2%。2.摄食率和消化率低导致鱼体从食物中获得可供利用的蛋白质水平不足是该种鱼SGR_w低的主要原因。3.摄食不同水平蛋白质饲料对该种鱼幼鱼的标准代谢率无明显影响。该种鱼SDA系数的范围为5.2-9.9%,低于已有研究结果。SDA系数与SGR_w之间存在显著的正相关关系,支持Jobling提出的高生长率导致高水平的SDA的观点。当低于最适蛋白质水平时,SDA系数随饲料蛋白质水平的增高而增高;当高于最适蛋白质水平,SDA系数会逐渐降低。4.中华倒刺鳃幼鱼生长能占摄食能的比例为23.02-27.56%（G%）,占同化能的比例为28.76-32.18%（G/A%）,低于已有研究中其它鱼类的结果,生长能分配比例较小是该种鱼生长慢的另一原因。5.分配较大比例的能量用于代谢,是中华倒刺鳃这种杂食性鱼类的生态习性所决定的能量对策。更多还原

【Abstract】 Two series of experiments were conducted on the Spinibarbus sinensis, an endemic freshwater fish of China. In experiment I, six isocaloric experimental diets containing different protein levels （20.5%, 26.5%, 34.2%, 41.0%, 49.9%, and 55.9%） were formulated, using white fish meal as the protein source. Each diet was randomly assigned to four groups of 12 fish for 10 weeks at 27.5℃in a circulated filtered rearing system. The effects of dietary protein levels on growth performance were investigated to find the optimal dietary protein level for S. sinensis. In experimentⅡ, the effects of dietary protein levels on standard metabolic rate and specific dynamic action （SDA） were investigated in juvenile S. sinensis fed for 10 weeks in experimentⅠ. Based on the data from the two series experiments, the nitrogen budgets and the energy budgets at the different dietary protein levels were compiled to approach the influence of dietary protein on growth in juvenile S. sinensis in terms of energetic mechanism.The results were as follows:1. As dietary protein increased gradually from 20.5% to 41.0%, the feed intake ratio of dry matter (FI_dm) and the feed intake ratio of energy （FI_e） decreased primarily, and then slightly increased. The maximum value of FI_dm (16.07 g kg^-1d^-1) and FI_e (0.25 MJ kg^-1d^-1) were attained by 20.5% group, and the minimum value of FI_dm (13.55 g kg^-1d^-1) and FI_e (0.21 MJ kg^-1d^-1) were attained by 41.0% group. As dietary protein increased from 20.5% to 55.9%, apparent digestibility of dry matter significantly decreased from 73.12% to 55.02% （p<0.05）, whereas, there was no significant difference in the apparent digestibility of protein among all treatments.2. Specific growth rates of weight （SGR_w） significantly increased primarily as dietary protein increased （p<0.05）, and then attained a plateau. From 20.5% to 41.0% groups, SGR_w increased from 0.60% d^-1 to 0.97% d^-1, but decreased to 0.96% d^-1 in 55.9% group. As dietary protein increased from 20.5% to 55.9%, the feed efficiency （FE） increased primarily, and then attained a plateau, and the protein efficiency ratio （PER） decreased from 178.23% to 116.60%, and the protein productive value （PPV） decreased from 23.92% to 18.62%。3. There was no significant difference in ash contents among all treatments. As dietary protein increased the body protein contents and moisture contents increased significantly （p<0.05）, whereas body lipid and energy density decreased significantly （p<0.05）. Analysis by correlation showed that dietary protein levels was positively correlated to body protein contents （r=0.678, p<0.01）, and negatively correlated to body lipid and energy density （i=-0.880, p<0.01; r=-0.828, p<0.01）.4. The standard metabolic rates （Rs） of all groups ranged from 106.8 mgO₂ kg^-1g^-1 to 109.1 mgO₂ kg^-1g^-1 and no significant difference was found among groups. The energy loss of specific dynamic action （SDAe） increased as the meal energy increased in all groups, and the rate of SDAe increased with the increasing meal energy was the fastest in 41.0% group. The relationships between energy intake and SDAe in all groups could be described as:20.5% group:SDA_E =33.630+0.047C （n=13,r=0.834,p<0.05）26.5% group:SDA_E=33.843+0.046C （n=14,r=0.915,p<0.05）34.2% group:SDA_E=35.893+0.061C （n=13,r=0.963,p<0.05）41.0% group:SDA_E=37.203+0.091C（n=13,r=0.971,p<0.05）49.9% group:SDA_E=32.485+0.066C （n=14,r =0.896,p<0.05）55.9% group: SDA_E=35.373+0.063C （n=14,r=0.809,p<0.05）5. The SDA coefficient, SDA peak value, SDA duration and factorial scope of SDA were significantly influenced by dietary protein levels （p<0.05）. In 41.0% group the values of SDA coefficient, SDA peak value, and factorial scope of SDA were all significantly higher than other groups. Among 34.2%, 49.9%, and 55.8% groups, there were no significant difference among SDA coefficient, SDA peak value, factorial scope of SDA, but these four gorups were all higher than 20.5% and 26.5% groups in all indexes （p<0.05）.6. The nitrogen retained in body （G_N%） in 41.0% group was significantly higher than those in other groups （p<0.05）, but the nitrogen loss of this group in excreta （U_N%） was lower （p<0.05）. Values of the nitrogen loss in feces （F_N%） among all groups have no significant difference. The nitrogen budget equation was 100C_N = 13.48F_N + 64.77U_N+ 21.75G_N. Analysis by partial correlation showed that G_N% was positively correlated to SGR_w （r =0.795,p<0.01）. Similarly G_N% were positively correlated with PER （r =0.862, p<0.01）.7. As dietary protein increased from 20.49% to 34.20%, the energy allocation to growth （G%） increased from 26.15% to 27.56%. However as the dietary protein level increased above 41.0%, G% significantly decreased （p<0.05）. As dietary protein increased from 20.5% to 55.9%, the energy loss in metabolism （R%） decreased significantly from 61.43% to 56.94% （p<0.05）. On the contrary, the energy loss in feces （F%） increased from 8.24% to 10.89% and the energy loss in excreta （E%） increased from 5.00% to 10.43% （p<0.05）.The energy budgets of all groups were:20.5% group: 100C=26.15G +61.43R+8.24F +4.19U26.5% group: 100C=26.85G+59.59 R+8.33 F +5.22 U34.2% group: 100 C = 27.56 G + 58.08 R+ 8.00 F + 6.37 U41.0% group: 100C = 27.10G + 58.51 R+8.48F + 5.91 U49.9% group: 100 C = 24.40 G + 57.10 R + 10.37 F + 8.13 U55.9% group: 100 C = 23.02 G +56.94 R+10.89 F +9.41 UThe average energy budget equation was 100C = 25.85G +58.61R + 9.05F+6.54 U.The average proportions of G and M in A were described by the equation: 100A = 30.57 G + 69.43 M. The conclusions suggested in this study were as follows:1. The optimal dietary protein requirement for the growth of juvenile S. sinensis at 27.5℃would be 39.6-42.2%.2. The lower SGR_w might be induced by poor FI_dm and apparent digestibility which make the fish get scarce dietary protein from diets.3. It suggests that dietary protein has no influence on standard metabolic rate of S. sinensis. The SDA coefficient of juvenile S. sinensis, 5.2-9.9%, are slightly lower than some other species. The SDA coefficients are positively correlated to SGRw, which is in accordance with Jobling’s theory. Below the optimum dietary protein level, SDA coefficient increases as dietary protein increases. But above that level, SDA coefficient would decrease as dietary protein increases.4. The energy allocated to growth ranges from 23.02% to 27.56% （G%） and accounts for 28.76%-32.18% assimilated energy （G/A%）, which is lower than some other fish species. It suggests that the lower energy allocation to growth is another reason for poor growth performance of S. sinensis.5. There is higher proportion of energy resource allocated to metabolism and lower proportion to growth in S. sinensis than piscivorous fishes. This pattern of energy allocation suggests an optimal energetic strategy adopted by this omnivorous species.更多还原