3.4. Growth parameters and body composition
There were no significant differences (P > 0.05) in the SR, WGR,
SGR and FCR between the PS1-3 treatments and the Florfenicol
group. However, significant differences (P < 0.05) were observed in
the WGR, FCR and SGR of the shrimp in the Florfenicol group
compared to the control group at the end of the experiment
(Table 5). The SR of shrimps fed with PS1 and PS3 were the highest
among all treatments (P < 0.05). The moisture of shrimps fed with
Florfenicol was significantly lower than that of the control group
(P < 0.05). However, supplementing probiotic decreased the body
crude lipid significantly (P < 0.05). There were no significant differences
(P > 0.05) on ash among the treatments (Table 6).
3.5. Immunity
The Table 7 showed that the THC in Florfenicol group was significant
higher than that in other treatment groups (P < 0.05) and
there were no significant differences among other treatment
groups (P > 0.05). The phagocytic rate in the control group was
significantly lower than that in other treatment groups (P < 0.05)
and there were no significant differences among PS2, PS3 and
Florfenicol groups (P > 0.05). The LSZ in control group was significant
lower than that in other treatment groups (P < 0.05). The SOD
in PS groups was significant higher than that in other treatment
groups (P < 0.05). The antibacterial activity in the control was
significantly lower than that in other treatment groups (P < 0.05)
except that PS1 and PS3 were significantly higher than that in the
Florfenicol group (P < 0.05). The PO in the control group was significant
lower than that in other treatment groups (P < 0.05) except
PS1 and there were no significant differences among other treatment
groups (P > 0.05).
3.6. Challenge