The Economy of Essential Elements
89
specific assimilation efficiencies corresponding to the three candidate
strategies identified in Appendix A3 [Eqs. (A3.14}-(A3.16], the following
growth models can be proposed for animals maintaining balanced growth
on nutrient-deficient food under different degrees of nutrient conservation
efficiency:
(4.18)
gl = g* ~- (1- (QI6)l)
(4.19)
g_ = g* ~ - (1-(QI6)/ K;)J
(4.20)
where Q and (J are the P contents of food particles and animals [(Ilg P)
(mg ct], g" = c" I' - r is the maximum growth rate.at saturating levels of
optimally composed food, and K"z= g"(c'n is the corresponding maximum
net growth efficiency.
1
,-..
* ~
--~
C1.)
1
~
....
-S
0
~
0
6h
C1.)
0
- - - '
>
''- oW
~
-
C1.)
"
o
1- K*
K*
1
2
2
Relative food P content (Q/ B)
Fig. 4.11. Hypothesized relationships between carbon-specific growth rate and food composition for
three different nutrient utilization strategies. Curves labeled 0, 1, and 00 are given by Eqs. (4.18)-(4.20)