. Rose petal meal as a natural carotenoid source for pigmentation and growth of dwarf gourami Colisa lalia.

Abstract

An experiment was conducted to observe the effect of feeding graded levels of rose petals meal (RPM) on carotenoids concentration in muscle and skin, weight gain, feed conversion ratio and biochemical composition of muscle of Indigenous ornamental fish, dwarf gourami (Colisa lalia). The control diet was prepared by using fish meal 25%, soyabean meal 22%, groundnut oil cake 15%, rice bran 20%, wheat flour 12%, starch powder 3%, soya oil 2% and vitamins-minerals 1%. Five experimental diets were prepared by supplementing RPM at five levels viz. 1, 2, 4, 6 and 8% of the control diet by replacing the same quantity of rice bran. The feeding trial continued for 45 days in dwarf gourami. At the start of the experiment the carotenoids concentration in the mixture of muscle and skin of dwarf gourami was 2.53 and 1.58 μg/g in male and female, respectively. At the end of the feeding trial total carotenoids concentration increased in proportion RPM supplementation in the diet, the highest (P<0.05) being in 6% level for both male (6.87 μg/g) and female (3.35 μg/g). The weight gain was higher in 6% RPM supplemented diets. Feed conversion efficiency was significantly lower (P<0.05) in 6% rose petal meal supplemented diets. Biochemical composition of fish flesh was not affected (P>0.05) due to incorporation of various level of PRM in the experimental diets. The results showed that rose petals meal can be supplemented at 6% levels in the diets of dwarf gourami for improvement of their colour through increase in the carotenoids concentration in skin and muscle without any adverse effect on growth and feed conversion efficiency.