Use of mannose oligosaccharide compositions for feeding crustaceans

1 . A method for feeding crustaceans, the method comprising feeding crustaceans a mannose oligosaccharide composition, wherein the composition

has a solubility in water of 50% or more;

comprises less than 0.1 wt % beta-glucan on a dry weight basis (db);

comprises at least 50 wt % of mannose oligosaccharides having a degree of polymerization of 3 or more on a dry weight basis (db); and

is obtained by polycondensation of mannose in a microreactor, wherein the pressure in the microreactor is from 0.5 bar to 30 bar.

2 . The method according to claim 1 wherein the mannose oligosaccharide composition is not obtained from yeast or vegetable fibres.

3 . The method according to claim 1 wherein the pressure in the microreactor is from 2.5 to 5.0 bar.

4 . The method according to claim 3 , wherein the polycondensation of mannose in the microreactor takes place at a temperature of 140 to 300° C. and wherein the residence time of the mannose in the microreactor is from 1 to 600 seconds.

5 . The method according to claim 1 wherein the mannose oligosaccharide composition comprises at least 50% α,β-(1,6) linkages and α,β-(1,3) linkages.

6 . The method according to claim 1 wherein the mannose oligosaccharide composition is in a liquid form, powder form, or supported on a solid carrier.

7 . The method according to claim 1 wherein the crustaceans are fed daily or every 2, 3, 4 or 5 days with the mannose oligosaccharide composition or with a feed composition comprising the mannose oligosaccharide composition.

8 . The method according to claim 1 wherein the crustaceans are selected from one or more crustaceans of the suborders Dendrobranchiata and Pleocyemata.

9 . The method according to claim 8 wherein the crustaceans are shrimp of the species Litopenaeus vannamei or Penaeus monodon.

10 . The method according to claim 1 wherein the amount of the mannose oligosaccharide composition in a feed composition is from 0.01 to 0.9 wt % of the feed composition, on a dry weight basis.

11 . The method according to claim 1 wherein feeding the crustaceans the mannose oligosaccharide composition results in one or more of:

decrease of the food conversion ratio;

decrease of the mortality rate of the crustaceans;

increase of the growth performance of the crustaceans;

increase of the growth of the crustaceans' intestinal microvilli, midgut epithelium and brushborder height, as measured by histology; and

increase of gut integrity;

as compared to when feeding the crustaceans

a diet without any mannose oligosaccharide composition; or

a diet with a mannose oligosaccharide composition having a mannose oligosaccharide content with a degree of polymerization of 3 or more of less than 50 wt % at the same inclusion rate in the diet; or

a diet with a mannose oligosaccharide composition having a beta-glucan content greater than 0.1 wt % on a dry weight basis at the same inclusion rate in the diet.

12 . A method for prophylactic treatment of crustaceans to prevent or reduce the severity of bacterial infections, the method comprising feeding the crustaceans according to the method of claim 1 .

13 . The method according to claim 1 wherein the pressure in the microreactor is from 1.6 to 3.0 bar.