Study of Effectiveness of Hygen Pro® Strept Phytobiotic versus Clinical Strains of Streptococcus Suis of Porcine Origin

Interesting topic and indeed very acute and actual problem in pig farms in many countries.

Without being totally familiar with the critical MIC levels for inhibiting pathogens, I wonder if a MIC-value of 1.5-3.0 mg/ml is really that low. Studies at the Vet. Faculty of the University of Ghent, show MIC values of one single SCFA lower than 0.03 mg/ml (13 sow strains) or one single MCFA at 0.25-0.5 mg. This means 50 to 100 times lower. Where is the synergy of the described product ?

Still if 1.5-3.0 mg/ml have to be respected, than we can easily calculate that dosage of the product need to be between 15 and 25 kg per ton of feed, in order to reach the critical concentration in the stomachal and small intestinal fluids. On top we guess the product is not 100% pure but must have some percentage of carrier (to absorb the liquid components). Also some digesta components and other bacteria in the gut can easily "consume" the components of the product as they are of course more numerous There is little evidence that the components of the product will selectively "attack" the Streptococcus bacteria without touching the other, which again would advocate that the IN VIVO dosage should be TIMES higher than the in vitro determined MIC concentration.
More-over running reliable IN VIVO trials with Streptococcus Suis is not that evident, as the pathogen never expresses in a homogenous and conisistent way.
So far as there is no lapsus in my above logic reasonings.
Luc.