Department of Animal Production, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh, Egypt.
Central Laboratory for Aquaculture Research, Abbassa, Sharkia, Sakha Aquaculture Research Unit, Kafrelsheikh, Egypt.
Fish Physiol Biochem. 2021 Aug;47(4):869-880. doi: 10.1007/s10695-021-00943-8. Epub 2021 Mar 26.
The trials of finding non-conventional and alternative aquafeed ingredients are increasing. In this sense, this study evaluated the influence of coconut oil on the growth, feed utilization, immune, and antioxidative responses of Nile tilapia. Five test diets were formulated by mixing coconut oil with the other ingredients at 0, 1, 2, 3, and 4% of the total ration and presented for tilapia for 60 successive days. The final weight, SGR, weight gain (WG), and feed intake were superior in fish delivered 2% of coconut oil (P < 0.05). Concurrently, fish that received 2% coconut oil had lower FCR and higher PER than fish of the control and 4% groups (P < 0.05). Higher lipase activity was observed in fish of 2% and 3% levels than the remaining groups (P < 0.05). Besides, the amylase and protease activities of fish in 1%, 2%, and 3% groups were higher than the 0% level (P < 0.05). The total blood cholesterol, RBCs, and PCV showed higher values in Nile tilapia fed 2% and 3% coconut oil (P < 0.05). The lysozyme and phagocytic activities were higher in fish fed 2% and 3% levels than the control (P < 0.05), while the phagocytic index in 2% and 3% levels was higher than 0% and 4% levels. Furthermore, SOD and CAT were higher in fish fed 1%, 2%, and 3% than fish fed 0% and 4% levels while GSH was higher in fish of 1%, 2%, and 3% than fish fed 0% level (P < 0.05). However, the MDA level was markedly lower in fish fed 25, 3%, and 4% coconut oil than the 0% level (P < 0.05). The intestine's histological structure in all groups appeared normal, forming of intestinal villi projecting from the intestinal wall. Also, the structure of the hepatopancreas had a normal architecture in all groups. To sum up, the inclusion of coconut oil at 2 to 3% is recommended as a replacer for fish oil in Nile tilapia diets.
寻找非传统和替代水产饲料成分的试验正在增加。在这种情况下，本研究评估了椰子油对尼罗罗非鱼生长、饲料利用、免疫和抗氧化反应的影响。通过将椰子油与其他成分混合，在总饲料中添加 0、1、2、3 和 4%，配制了五种试验饲料，并连续 60 天投喂罗非鱼。添加 2%椰子油的鱼的末重、特定生长率、增重和饲料摄入量均优于对照组和 4%组（P<0.05）。同时，与对照组和 4%组相比，摄入 2%椰子油的鱼的饲料转化率和 PER 更低（P<0.05）。2%和 3%组的脂肪酶活性高于其他组（P<0.05）。此外，1%、2%和 3%组的鱼的淀粉酶和蛋白酶活性高于 0%组（P<0.05）。摄食 2%和 3%椰子油的尼罗罗非鱼的总血胆固醇、红细胞和 PCV 值较高（P<0.05）。摄食 2%和 3%椰子油的鱼的溶菌酶和吞噬活性高于对照组（P<0.05），而 2%和 3%组的吞噬指数高于 0%和 4%组。此外，摄食 1%、2%和 3%椰子油的鱼的 SOD 和 CAT 高于摄食 0%和 4%水平的鱼，而摄食 1%、2%和 3%椰子油的鱼的 GSH 高于摄食 0%水平的鱼（P<0.05）。然而，摄食 25%、3%和 4%椰子油的鱼的 MDA 水平明显低于摄食 0%水平的鱼（P<0.05）。所有组的肠道组织学结构均正常，形成从肠壁突出的肠绒毛。此外，所有组的肝胰腺结构均具有正常的形态。总之，建议在尼罗罗非鱼饲料中添加 2%至 3%的椰子油来替代鱼油。
