Agriculture Reference
In-Depth Information
D.hansenii strain CBS 8339 enhanced leopard grouper growth performance but did not signif-
icantly affect the assayed immunological parameters after 4 weeks of feeding (Reyes-Becerril
et al . 2011). However, post infection with A. hydrophila , fish fed the yeast-supplemented
diet displayed a significant increase in the levels of plasmatic IgM, SOD and CAT activities.
CAT and HSP70 gene expression in liver were up-regulated before and after infection of A.
hydrophila .
10.6 TILAPIA
After carps, tilapias are the second most abundantly produced fish group with total global
production approaching 4 million tonnes in 2011 (FAO FIGIS 2013). The Nile tilapia
( Oreochromis niloticus ) accounts for the largest volume (2.8 million tonnes), followed
by Nile-blue hybrid ( Oreochromis niloticus × Oreochromis aureus ; 360,000 tonnes), the
Mozambique tilapia ( Oreochromis mossambicus ; 35,000 tonnes) and various other species
and hybrids.
Relative to other fish species, the application of probiotics to tilapia is extensive
(Table 10.5). Bacillus spp. ( B . coagulans , B. subtilis , B. licheniformis , B. pumilus and B.
firmus), ), LAB ( Lb. plantarum , Lb. rhamnosus , Lb. acidophilus , Lb. brevis , E. faecium , P.
acidilactici and Lc. lactis ), other Gram-positive species ( Micrococcus luteus and Clostridium
butyricum ), Gram-negative species ( Pseudomonas spp., Rhodopseudomonas palustris and
Citrobacter freundii ) and yeast ( S. cerevisiae ) have been tested in tilapia trials. The majority
of these studies have focused on Nile tilapia and applications have demonstrated a range of
growth benefits (Lara-Flores et al . 2003; Aly et al . 2008b; 2008c; Wang et al . 2008b; Essa
et al . 2010; Zhou et al . 2010a; 2010b; Jatoba et al . 2011), stimulated some aspects of the
non-specific immune response (Aly et al . 2008b; Wang et al . 2008b; Ferguson et al . 2010;
Zhou et al . 2010a; 2010b; Goncalves et al . 2011; Jatoba et al . 2011; Pirarat et al . 2011;
Villamil et al . 2012; Liu et al . 2013; Standen et al . 2013) and improved resistance to various
bacterial pathogens (Aly et al . 2008a; 2008b; Ngamkala et al . 2010; Villamil et al . 2012;
Liu et al . 2013). A comprehensive review of probiotic applications in tilapia is presented by
Welker and Lim (2011).
10.6.1 Effects of probiotics on tilapia growth performance
Improved tilapia growth performance has been reported with the application of M.luteus (Abd
El-Rhman etal . 2009), E.faecium (Lara-flores etal . 2003; Wang etal . 2008b), Lb.acidophilus
(Lara-flores et al . 2003; Aly et al . 2008b), Lb. plantarum (Essa et al . 2010; Jatoba et al .
2011), Lc. lactis (Zhou et al . 2010b), B. coagulans (Zhou et al . 2010a), B. pumilus (Aly et al .
2008c), B. subtilis (El-Haroun et al . 2006; Aly et al . 2008b; Essa et al . 2010; Salem 2010),
B. licheniformis (El-Haroun et al . 2006), Rhodopseudomonas palustris (Zhou et al . 2010a)
and S. cerevisiae (Lara-flores et al . 2003; Abdel-Tawwab et al . 2010; Essa et al . 2010). Such
improvements can lead to considerable economic gains (El-Haroun et al . 2006).
The mechanisms behind these improvements in growth performance are not fully eluci-
dated, but a number of studies have reported elevated GI digestive enzyme activities in fish fed
probiotics, which is likely to be a contributory factor. For example, concomitantly with ele-
vated growth performance, elevated amylase, protease and lipase activities have been observed
in tilapia fed B. subtilis and/or Lb. plantarum and elevated protease activity in tilapia fed
 
Search WWH ::




Custom Search