Background:
The non-availability of nutritionally complete feeds of global performance standards has been a critical limiting factor for the expansion and intensification of rainbow trout farming in the Indian uplands. Particularly, in the critical nursery rearing period, the use of sub-optimal feeds leads to low survival, growth impairment, size heterogeneity / cannibalism, body deformities and increase disease susceptibility. Therefore, we developed this high-performance rainbow trout starter feed with the aim to improve the quantitative and qualitative output of rainbow trout seed or stock-size fish from hatcheries situated across the trout farming states of India. As on 2023, the total volume of rainbow trout starter feed required in India is 60 tonnes:
Technology details:
Through a series of laboratory experimentations and field evaluation studies, ICAR DCFR has developed and validated a high-performance rainbow trout starter feed formulation which consistently enhanced growth, feed use efficiency, survival, fitness traits and size homogeneity in rainbow trout nurseries, while substantially reducing culture duration, disease incidence, malformations and feed wastage. The best performing formulation was arrived at based on various response criteria such as growth, feed use, survival, size homogeneity, morphometric-histological indices and molecular biomarkers related to growth and metabolism. On a comparative scale, this feed outperformed the existing trout starter feeds by 50-90% difference in weight gain. Survival was greater than 85% in all the test sites. Feed conversion ratio was found to range 0.8 to 1.2, with substantially less feed wastage. Importantly, the duration of nursery rearing was reduced from 75- 90 days to 45-60 days. Overall, this technology offers the clients with a high-performance rainbow trout starter feed formulation and feed management schedule in rainbow trout hatchery.