International Journal of Aquaculture, 2017, Vol.7, No.4, 23
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has been working hard on improving the existing technologies or developing new ones for increased and sustained
production.
Maturity and Breeding periods in different Himalayan States
Rainbow trout normally although attains sexual maturity at an age of 3 years however, feeding strategy,
temperature, light conditions influence it. We have observed that maturity and breeding of rainbow trout differs
comparatively in different Himalayan states. In Sikkim, temperature remains comparatively on higher side with an
optimal range of 14-18
°
C for 8 months in a year consequently rainbow trout performs breeding during second
week of November. However, in Himachal Pradesh rainbow trout performs breeding earlier than in J & K due to
slightly higher thermal regime and other. In Uttarakhand, temperature remains 1-3.2
°
C higher at ICAR - DCFR
trout farm in Champawat than the other states it usually breeds during the first week of January (Table 2). The age
range of females producing the highest quality eggs was observed as four years and the average number of eggs
per kilogram of female body weight varies between 1 500 to 2 000 at different locations.
Table 2 Relative breeding period of rainbow trout in different Himalayan states
State names
First spawning
Last spawning
Responsible factor
Sikkim
II week of Nov.
I week of Jan.
Comparatively higher thermal regime
and longer photo period than J&K.
Himachal Pradesh
I week of Dec
II week of Feb.
Slightly higher thermal regime than J
& K
J & K
II week of Dec
III week of Feb.
Low thermal regime as compared to
other states
Uttarakhan
I week of Jan at Champawat
II week of Jan at Bairangna,
Uttarkashi
III week of Feb.
1 to 3.2
℃
higher at Champawat than
Bairangna and higher thermal regime
amongst other states
Major R & D Initiatives
In recent years, farmers have shown greater interest in commercial trout farming. Production enhancement of
rainbow trout in the country needs both vertical and horizontal expansion. Requirement of technological advances
in the form of improved feed having low FCR, farm design with greater efficiency, optimization of stocking
density, broodstock maintenance and hatchery practices is necessary for the future development of trout farming
in India (Pandey and Ali, 2015). Marketing of the final produce is another constraint in the spread of rainbow
trout farming. Since farms are located in remote areas in the hills with poor transportation facilities, access to
market is a real challenge. Trout is a high value low volume fish and highly perishable commodity, the produce
needs to be transported in shortest possible time under refrigerated condition to fetch good price. In the absence of
cold chain facilities and reliable market linkage expansion of rainbow trout farming on a commercial scale will be
difficult. Value addition of the final produce will be needed to increase sales and consumption of rainbow trout.
Moreover, certain basic issues need to be scientifically addressed.
A. Culture environment
The DCFR undertook R&D activities to evaluate the comparative growth performance of the rainbow trout
Oncorhynchus mykiss
from different Himalayan states. At experimental farm, Champawat, Uttarakhand the
recorded average growth was 200 g, 1 100 g and 2 100 g at first, second and third year of rearing respectively at
the thermal regime of 4.5-20
o
C (Joshi et al., 2005). In another field study in central Himalaya, average growth was
recorded as 300 g (range 260 - 400 g) at thermal regime of 5.0 - 22
o
C (Vass et al., 2010). The reported / generated
information suggested that higher temperature in mid altitudes of Himalayas can help better yield of rainbow trout,
provided farm management practices are optimized (Pandey and Ali, 2015). Generally, it takes 12 - 14 months to
attain marketable size (250 – 260 g) in J & K, Himachal Pradesh and Garhwal region of Uttarakhand. However,
comparatively better growth of 500 - 600g was observed in 12 months at state Govt. farm and private farms in
West Sikkim. This was due to favourable thermal range of water (14-18
o
C for 8 months in a year) and availability
of sufficient water volume. In Nepal, marketable size of 200 - 300 g reaches at 14 - 16 months of culture period
with the stocking density of 50 fish/m
2
(Swar, 2007; Rai et at., 2008). Whereas the fish takes approximately 8
