The Lille, France headquartered company said ProSaf is aimed at improving protein digestibility, feed intake and growth performance in low-fishmeal shrimp and fish diets, rather than 1 to 1 replacement of fishmeal in the diet.
Free amino acids, glutamic acid and nucleotides from yeast cell content increases shrimp feed attractability and palatability, when those small soluble molecules are released into the water, the product also improves primary defenses in shrimp through increasing the total hemocyte count and phenoloxidase activity, said the company
The pressure to reduce fishmeal usage in aqua feeds is one of the limiting factors for growth in the aquaculture industry, but there are technical challenges associated with low fish-meal diets, said Otavio Serino Castro, global species manager/aquaculture, Phileo Lesaffre.
He told us that inclusion rates with ProSaf range from 0.5 to 2.5% of the complete shrimp feed, making it cost effective: “This is one point of differentiation for us.”
The final amount used, within that 0.5-2.5 range, will be determined by the quality of the fishmeal or other alternative protein sources used in the diets, he added.
The yeast extract, which is a feed material, can be used at all shrimp life stages, and in other aquaculture species.
ProSaf is obtained from primary culture of a proprietary Saccharomyces cerevisiae baker’s yeast strain. The company said it is a high quality product due to the fact it selects the strain, it controls the process and it can guarantee consistency.
“We screened yeast species to get one that would fit with our specifications and we adapted the fermentation process to finally get a product rich in hydrolysed protein (>63%), in the form of low molecular weight peptides (less than 3.6 kDa) and free amino-acids,” said Nadège Richard, aquaculture R&D manager, Phileo Lesaffre.
Digestibility, performance trials
She said the company first ran digestibility trials on ProSaf in terms of its protein and essential amino components, with its crude protein component showing 88.9% digestibility and essential amino acids higher than 95%.
“Then we went to in-vivo trials in shrimp, we did these in several parts of the world – one trial in Brazil to assess the effect of inclusion of ProSaf on feed intake in a low-fishmeal formulation. We saw that it improved feed intake in [this type of diet]. We also did a performance trial in Asia - in Thailand in 1g to 10g shrimp - and the effect of [ProSaf inclusion] on growth and some indicators of immune status. We saw an improvement in growth when we added this product in a low-fishmeal formulation and we also saw an improvement in immune status.”
Phileo Lesaffre, she said, is also now looking beyond shrimp feed formulation, evaluating the use of ProSaf in fish diets. A digestibility trial is currently underway in Portugal. “We will focus on salmonids, in fact,” said Richard.
