Prosaf® improves growth performance of shrimp fed with low fish meal diet
by Phileo by Lesaffre.
The challenge of low fish meal diets
The increasing price of fish meal and its reduced availability have pushed the aquaculture industry to develop new feed formulations with plant-based ingredients replacing a significant proportion of fish meal content. Although vegetable sources like soy, rapeseed, and sunflower, are high in protein content, they present several pitfalls that hinder shrimp production.
The main drawback of plant-based protein sources is the presence of anti-nutritional factors (ANFs), like proteinase inhibitors and tannins, among others, that have not been inactivated during feed processing.
ANFs are molecules naturally produced by plants and shaped by evolution to deter predators. When ingested in small amounts, such molecules affect feed digestibility, thereby reducing feed efficiency and growth performance, and when ingested in large amounts, they can even become toxic.
Plant-based ingredients also show negative consequences for the feeding process. Particularly, shrimp fed feed with plant-based ingredients often show a slower and less efficient feeding process. This leads to the loss of nutrients through leaching into the water which, in turn, increases feed conversion ratios (FCR) and decreases nutrient availability, and thereby ultimately reducing shrimp growth performances.
For all of the above reasons, the shrimp aquaculture industry is facing a pressing need for new feed formulations that allow to reduce fish meal in feed without impairing shrimp growth performance. Prosaf®, a premium yeast extract developed by Phileo by Lesaffre, is an alternative to the limitations of plant-based protein sources.
Prosaf®: Premium quality and superior performance
Prosaf® is a selected yeast extract obtained from primary culture of a proprietary Saccharomyces cerevisiae baker's yeast strain. After fermentation, the yeasts are autolysed and subsequently centrifuged to separate the yeast extract from the cell wall.
The yeast extract fraction is composed of 63 percent of protein, most of which comprises low molecular weight peptides that show high bioavailability and that can be easily absorbed by shrimps. Moreover, Prosaf® feed additive is rich in essential amino acids, 46 percent of which are free and, therefore, also easily assimilated.
A recent scientific trial carried out at the Prince of Songkla University, Thailand, addressed the effect of the supplementation of Prosaf® on the growth performance of Whiteleg shrimp (Litopenaseus vannamei) fed a low fish meal diet (5% fish meal).
The low fish meal formulation was used in several experimental treatments with increasing concentrations of the yeast extract ranging from 0-to-2.5 percent. After nine weeks, the body weight, feed intake and FCR were measured and compared to the control treatment, where Whiteleg shrimp were fed a high fish meal diet (15%).
Results showed that the feed additive Prosaf® can revert the negative growth consequences of reducing fish meal level in shrimp feed (See Figure 1). Moreover, the Prosaf® feed additive shows a dose-dependent effect on shrimp growth performance, with increasing levels of the yeast extract resulting in improved body weight gain.
After the trial ended, body weight of shrimp supplemented with Prosaf® at 2.5 percent was one-gram higher than shrimp fed with the low fish meal diet, indicating a 12 percent individual biomass increase.
This scientific trial also addressed the effect of Prosaf® supplementation on FCR. Whereas decreasing fish meal level from 15 percent to five percent notably increased the FCR, the use of the feed additive Prosaf® to the low fish meal diets decreased shrimp FCR (See Figure 2).
It is important to highlight that a dose dependent response to the yeast extract supplement was observed, which resulted in decreasing FCR levels with increasing dosage of the feed supplement, down to the levels recorded for the high fish meal control treatment.
Supporting the transition to low fish meal diets
This scientific trial shows that Prosaf® feed additive provides a nature-based solution to reverse the negative effects that replacing fish meal with plant-based protein alternatives has on shrimp growth performance.
This is associated with the unique composition of this feed supplement and with the large content of highly bioavailable molecules. Ultimately, this product helps the shrimp aquaculture industry address the pressing challenges of developing new feed formulations, particularly to facilitate the transition from high to low fish meal feed formulations, which must develop into environmentally sustainable and more economically advantageous alternatives in the long run.