When balancing feed with sulphur-containing amino acids, feed producers have the choice between DL-Methionine (DL-Met) and Methionine Hydroxy-analogue (Met-Ha). Adisseo shows that the acidifying effect of their Met-Ha (Rhodimet AT 88) can save on organic acid costs.
Met-Ha has similar acidifying benefits than organic acids on improving intestinal microflora and nutrient digestibility in poultry and swine. For example, 2.4 kg of Met-Ha can spare 0.7 kg of formic acid per ton of poultry feed, saving at least €0.50 per ton of feed and even releasing more space in feed formulation.
The first effect of organic acids is to optimize gastric acidification. In vitro trials carried out on a monogastric gut model prove that Met-Ha decreases the need for HCl gastric secretion to achieve a target pH 2.
When talking about stomach acidification, nutritionists pay also attention to the buffer effect of feed. “The total buffer effect of a diet can be calculated from the ABC (Acid Binding Capacity) values of each ingredient. The aim is to lower the dietary ABC through organic acid supplementation to reach optimum gastric pH.
“Modelling the ABC decrease through pKa and molecular weight of the different organic acids has allowed us to develop practical software to better value all organic acids including hydroxy-analogue of methionine.” explains Dr Yves Mercier, Research Manager, Amino Acids and Proteins, at Adisseo.
As an example, the ABC-4 value of formic acid is -17,000 mEq/kg and Rhodimet AT88 about -5,000 mEq/kg.
The in vitro inhibition efficacy of Rhodimet AT88 against Salmonella pullorum, S. typhimurium, S. enteritidis, Clostridium perfringens and Campylobacter jejuni, 5 standard strains of major enteric pathogens, is closer to potassium diformate and formic acid, at same molecular contents, and stronger than lactic acid.
In vivo trials, also have shown that RhodimetAT88 is effective at reducing the global gut microbiota amount and the frequency of detection of Campylobacter species.
Moreover, tests have shown that methionine hydroxy-analogue also strongly inhibits mould development (up to -50% for Aspergillus flavus or Fusarium verticillioides) at standard feed incorporation rate (2.5 kg/ton).
1 kg of Rhodimet AT88 appeared even as efficient as 1.25 kg of potassium sorbate on Fusarium graminum.
The acidifying value of Rhodimet AT88 is largely proven by experimental results reported in scientific publications and communications.
For a more practical use of the acidifying potential of methinonine hydroxy-analogue, Adisseo
has developed a simple calculator to determine the acid equivalence of Rhodimet AT88 compared to organic acids.