飼料中添加不同濃度與來源之類胡蘿蔔素對紅色吳郭魚體表增豔效果之影響

Abstract

吳郭魚目前是台灣水產養殖業年產量最多的魚種。紅色吳郭魚（Oreochromis sp.）是由莫三比克種吳郭魚突變而來。本實驗目的即為探討在飼料中添加不同來源與濃度的類胡蘿蔔素對紅色吳郭魚體表增豔效果之影響。 實驗分為兩部分，兩次實驗所使用之飼料皆添加兩種不同來源之類胡蘿蔔素，分別為由基因轉殖之大腸桿菌粉末中所含之類胡蘿蔔素與人工合成的還原蝦紅素。實驗一所使用魚隻為平均重量約2.6 g之紅色吳郭魚，實驗飼料分為五組，分別為對照組（Ctrl）與添加基因轉殖大腸桿菌粉末中所含類胡蘿蔔素50與100 mg/kg（E-50、E-100）及添加人工合成還原蝦紅素50與100 mg/kg（R-50、R-100）。實驗期間為十週，實驗後測定成長及色差計量化體表顏色，並取下魚皮進行類胡蘿蔔素分析。實驗二使用之飼料配方同實驗一，實驗魚隻則改為平均體重約為53 g之紅色吳郭魚，飼養期間為60天，每15天採樣、測量一次。 兩次實驗之結果均顯示在紅色吳郭魚的飼料中添加類胡蘿蔔素對成長及飼料效率沒有顯著影響。根據色差計所測得之數據顯示在飼料中添加類胡蘿蔔素對魚體表之紅色與黃色程度可以有效提升，實驗一其色彩平均差異值（△E）為8.06∼14.89，實驗二則為9.06∼14.15，均到達目視即可直接察覺差異的標準（△E > 6.0）。魚皮類胡蘿蔔素含量測定的結果，在實驗一之測量數值以對照組（Ctrl）最低，為0.25 mg/100g skin，其餘各組以E-100組為最高，類胡蘿蔔素含量為0.84 mg/100g skin；實驗二之測量結果與實驗一相似，均以對照組為最低，每15天採樣一次經60天後結果為0.33∼0.69 mg/100g skin，而E-100組為最高1.67∼4.08 mg/100g skin。

Tilapia is now the primary product of aquaculture industry in Taiwan. Red Tilapia (Oreochromis sp.) was mutate from the Mozambique tilapia species. The purpose of this study is to explore the effects of dietary carotenoids supplements on the integument pigmentation of the red tilapia (Oreochromis sp.). Experiment is divided into two parts. Two experiments were used to add different sources of carotenoids: gene transfered Escherichia coli powder and synthetic astaxanthin. In the 1st trial, mean weight of the red tilapia was about 2.6g. Experimental diets were divided into five groups, control group (Ctrl); E-50、E-100 were supplemented with gene transfered Escherichia coli powder with two different carotenoid contents, 50 and 100 mg/kg diet; R-50、R-100 were supplemented with synthetic astaxanthin, 50 and 100 mg/kg diet. The experiment period was 10 weeks. The 2nd trial used the same formula with the 1st trial, and the mean weight of the red tilapia was about 53 g. Experiment last for 60 days, sampling every 15 days. Fish skin were tested with tristimulus colorimeter, and further quantified for integument pigment. The results postulated that carotenoids have not obvious effects on the growth performance and feed efficiency, but improve pigmentation by enhanced a and b values in the red tilapia. In the 1st trial, the △ E varied from 8.06 to 14.89, while the content of carotenoids in red tilapia’ s integument varied from 0.25 to 0.84 mg/100g integument. In the 2nd trial, the △ E varied from 9.06 to 14.15, the integument pigmentation measurement results similar with the 1st trial: Ctrl was the lowest (0.33 ~ 0.69 mg/100g integument), and E-100 group was the highest (1.67 ~ 4.08 mg/100g integument).