Laboratory tests of 8-quinolinol as an additive to volatile fatty acids for preserving hay and other feedstuffs

Abstract

One part of 8-quinolinol in ten parts of propionic acid, either free or part-neutralised with ammonia, halved the acid required for preserving grass and lucerne hays, beans, rape seed and cereal grains containing sufficient moisture to mould. Propionic acid with 8-quinolinol delays moulding and diminishes the rate of spread of mould growth so that maximum temperatures attained are lowered and growth of thermophilic organisms is prevented. The application of 8-quinolinol and propionic acid to grass on cutting with, or without, use of formic acid as desiccant assisted inhibition of moulding especially in conjunction with ammonium propionate treatment after drying. The additive acts by inhibiting the growth of fungi which tolerate and degrade propionic and related fatty acids. The growth of two such fungi, Paecilomyces varioti and Aspergillus glaucus, is inhibited in culture by much smaller concentrations (less than 200 μM or 30 ppm) of 8-quinolinol than are required on hay, which strongly absorbs the additive and makes it less effective.