|Abstract: ||本研究探討投餵添加不同濃度的沙漠植物－仙人掌(Yucca shidigera)萃取物(Yucca Plant Extract, YUPE)的飼糧對於黃鱲鰺(Snubnose Pompano, Trachinotus blochii)幼魚的成長活存表現，並了解YUPE對魚苗其蛋白質效率、耗氧與排氨的影響。研究分三試驗進行： 試驗I：黃鱲鰺幼魚攝食添加不同濃度的YUPE飼糧六週，YUPE飼糧兩種添加濃度為150 mg kg-1和300 mg kg-1，不添加YUPE飼糧者為控制組，結果顯示：各飼糧處理間生長率及活存率皆無差異。如此養成的魚分別在22℃和26℃下在密封容器進行活存時間，耗氧率，和產氨率的測量與比較。結果顯示：耗氧率在低YUPE組比在高YUPE組和控制組低，而高YUPE組和控制組兩個組之間沒有差異。控制組的產氨率最高, 低YUPE組和高YUPE組則較低。低YUPE組活存時間最長，高YUPE組次之，控制組最短。魚在22℃比在26℃有較長的活存時間，及較低的耗氧率和產氨率。在二個溫度下，活存時間、耗氧率和產氨率對YUPE的處理的反應是一致的。 試驗II：本試驗目的是要瞭解飼糧添加YUPE對魚苗攝食量的影響及最適投餵量。結果顯示：不論是控制組(0 mg kg-1)或高YUPE組(450 mg YUPE kg-1)飼糧，魚苗的攝食量皆沒有差異。同時也得知最大攝食量為魚體總重的8%。 試驗III：本試驗比較不同蛋白質含量(48%、54%)及不同YUPE濃度(0 、150、300和450 mg kg-1)交叉組合成八種飼糧對黃鱲鰺魚苗的成長活存、蛋白質利用和耗氧排氨的影響。七週飼育試驗結果顯示：飼糧添加YUPE可以提升魚苗的活存及成長，降低魚苗的的耗氧率和產氨率，增長魚苗的活存時間，提昇魚苗的蛋白質消化率、乾物消化率、蛋白質效率、蛋白質蓄積率和能量蓄積率。 整體而言，飼糧添加150 mg kg-1 YUPE是對黃鱲鰺幼魚及魚苗數方面皆有最大效益的劑量。|
This study was to find out the effects of dietary YUPE (Yucca plant (Yucca shidigera) extract) on growth, survival, feed efficiency, protein efficiency, oxygen consumption, and oxygen consumption of fry and juvenile of Snubnose pompano (Trachinotus blochii). Experiment I: Juvenile fish were fed diets containing YUPE at 0, 150, and 300 mg kg-1 for 6 weeks. No differences in survival and growth were found among treatments. The resulting fish were kept in tightly capped bottles until death under 22 an 26°C to measure their survival time, oxygen consumption rate, and ammonia production rate. Oxygen consumption rate was lower at low YUPE group than high YUPE group and control group, but no difference between the latter two. Control group had the highest ammonia production rate than both YUPE groups. Low YUPE group had the longest survival time, followed by high YUPE group and control group. Fish under 22 °C had longer survival time, lower oxygen consumption rate and ammonia production rate than under 26 °C. YUPE effects on survival time, oxygen consumption rate and ammonia production between 2 temperature regimes were parallel. Experiment II: This study was to find out dietary YUPE effects on palatability and optimal feeding quantity of Snubnose pompano fry. No difference in feed intake between control group and high YUPE (450 mg-1 kg) group was found. Optimal feeding quantity was 8% body weight, no insufficient or left over. Experiment III: Eight diets containing 2 protein content (48 and 54%) and 4 YUPE concentrations (0, 150, 300, 450 mg kg-1) were fed to Snubnose pompano fry for 7 weeks to find out their effects on growth, survival, feed efficiency, protein efficiency, oxygen consumption, and oxygen consumption. The results showed that YUPE could increase survival and growth of fish, reduce oxygen consumption rate and ammonia production rate, lengthen survival time, enhance protein digestibility, dry matter digestibility, protein efficiency, protein deposition rate, energy deposition rate, and feed conversion rate. Fish composition showed ash content decreased as protein content increased at increasing dietary YUPE concentration. In conclusion, addition of YUPE in feed was beneficiary to Snubnose pompano fry rearing and the optimal level was 150 mg kg-1.