Effect of Choerospondias Axillaris (Roxb.) B. L. Burtt & A. W. Hill (Lapsi Fruit) on Growth, Biochemical and Immuno-Haematological Performance in Fishes

Abstract

Aquaculture is probably the fastest growing food-producing sector that accounts for 50% of the world's fishes that are used for food. Fish contributes over 20% of the animal protein intake for more than 2.6 billion people around the world. Hence, fish and fisheries make a major contribution to nutritional security and the fight against hunger and poverty in Asia. Immunostimulants are attractive substances that activate the immune system to prevent diseases and improve the body’s natural resistance to various viral and bacterial infections. These biologically active substances are products derived from natural sources or are synthetically made with different chemical properties and mechanisms of action. Lapsi, Choerospondias axillaris, is an indigenous fruit tree of Nepal found growing within 9002000 m above sea level in many parts of the country. Nepal is unique for processing and use

of Lapsi fruits, which are rich in vitamin C content. Lapsi fruits are consumed fresh, pickled

and processed for

preparing a variety of sweet and sour, tasty food products locally called Mada and candy. It is grown in 301 Village Development Committees of 29 hill districts of Nepal for socio-economic purposes. Like other medicinal fruits, lapsi also acts as immunostimulants and enhances the immunity of fish in aquaculture. Considering Lapsi's potential to boost immune response in fishes, three experiments were designed to investigate the effect of Choerospondias axillaris (Roxb.) B. L. Burtt & A. W. Hill (Lapsi fruit) on growth, biochemical and immuno-haematological performance in three fish species: indigenous major carp rohu Labeo rohita, common carp Cyprinus carpio, and rainbow trout Oncorhynchus mykiss under three climatic conditions, namely Gunjnagar, Chitwan for Tarai climate, Kathmandu Valley in the Aquaculture Research Laboratory of Central Department of Zoology, Tribhuvan University, Kirtipur for hilly climate and Sosod Trout Farm at Ranipauwa, Nuwakot, Trishuli, Nepal, for Himalayan climate, respectively. In each experiment six different doses of lapsi-incorporated diets were prepared as T1, T2, T3, T4, T5 and T6 containing 0, 100, 200, 400, 800 and 1600 mg kg -1 ethanol extract of lapsi fruits along with other usual ingredients (i.e., fish meal, wheat flour and cod liver oil). Fish were fed at 3% of their body weight daily at 9 a.m. and 4 p.m. for 90 days and at the end survival rate, growth performances (i.e., weight gain, SGR and FCR) were measured. Total protein, albumin, globulin and A/G ratio in blood serum, brain and muscles were quantified. To understand the haemato-immunological parameters, SGOT, SGPT and ALP in the liver and gills and complete blood profile were monitored. The weight gain and SGR increased as the doses of lapsi fruit extract increased while the reverse was found for FCR. As the doses of lapsi fruit extract increased in the diets, SGOT, SGPT and ALP levels decreased in all three experiments. Blood profile was always in the normal range. In conclusion, the 400 mg kg

ethanol extract of lapsi fruits-incorporated diet was found to be beneficial for fish growth, enhanced immunity and low mortality. Lapsi's vitamin C content might be the main contributor in enhancing the quality of fish feed, thereby resulting in favorable fish performance. Thus, farmers can use lapsi-supplemented fish feed, particularly during climate change, to maximize production of local fish species. In Nepal, aquaculture is still in its infancy, but has huge potential for development. However, information regarding the effect of lapsi on various species of fish in Nepal and other countries is limited.