3.5. Nutritional composition and fodder potentials
The nutritional composition of the seaweeds in this study and
the three most common seaweeds used as holothuria feed (Laminaria
japonica, Entermorpha prolifera and S. thunbergii) are summarized
in Table 5. The ash contents of S. hemiphyllum in the control
site and fish farm were 17.16% and 15.85%, respectively, which
were lower than those of S. henslowianum, L. japonica and E. prolifera,
but higher than that of S. thunbergii. The crude protein contents
of the seaweeds in this study ranged from 11.7% to 14.0%, which
were higher than those of L. japonica and E. prolifera but lower than
that of S. thunbergii. The crude fat contents of the seaweeds in this
study ranged from 2.2% to 2.7%, with the maximum and minimum
values observed in S. hemiphyllum grown in the control site (2.7%)
and fish farm (2.2%), respectively. Both Sargassum spp. in this study
contained higher crude fat contents than those of the other three
seaweeds used as holothuria feed (ranging from 0.2% to 0.41%),
suggesting higher nutritional value. However, as indicated previously,
the heavy metal contents (Cr, Pb or Cd) of S. henslowianum
exceeded the MAC of aquatic feed. Hence, its fodder potential
was lower than that of S. hemiphyllum