How do dietary methionine sources and feeding frequency impact the post feed hemolymph methionine levels in whiteleg shrimp?

by Dr Karthik Masagounder, Head Aqua and Swine Research, Evonik Nutrition and Care GmbH, Germany and Dr D Allen Davis, Professor, Auburn University, USA

An in-vitro study based on the enzymes extracted from shrimp hepatopancreas showed that shrimp are able to completely cleave the four available isomers of DL-methionyl-DL-methionine (AQUAVI® Met-Met) but at different rates. This allows delayed liberation and absorption of D- and L- Methionine (Met) in the digestive tract. However, no in-vivo data were published showing changes in the postprandial profile of Met in the hemolymph – a fluid analogous to the blood in vertebrates – of shrimp fed different Met sources.
 

We therefore instigated a study to investigate and compare postprandial Met levels in relation to other amino acids in the hemolymph of whiteleg shrimp fed diets supplemented with AQUAVI® Met-Met or DL-Met. The effects of different sources on the Met levels of shrimp hemolymph were evaluated under two feeding frequencies (once per day and three times per day) to understand if the feeding frequency would influence the dietary effects on the hemolymph Met levels.

Met is typically the first limiting amino acid in the practical shrimp feed and therefore its supplementation is essential. Previous studies showed that AQUAVI® Met-Met is a more efficient Met source (≥ 200%) for shrimp compared with DL-Met (Xie et al. 2017; Niu et al. 2018). Better bioavailability of AQUAVI® Met-Met versus DL-Met is attributed mainly to (i) its less water solubility and leaching and (ii) slow and long release of Met from different sterioisomers (DL-Met-Met, LD-Met-Met, LL-Met-Met, DD-Met-Met).

Read more, HERE.

The Aquaculturists

---