Acta Univ. Agric. Silvic. Mendelianae Brun. 2004, 52, 15-22
Published online 2015-07-03

Comparison of the effect of benzoic acid addition on the fermentation process quality with untreated silages

Petr Doležal

Ústav výživy a krmení hospodářských zvířat, Mendelova zemědělská a lesnická univerzita v Brně, Zemědělská 1, 613 00 Brno, Česká republika

The influence of benzoic acid and formic acid (positive control) of ensilaged maize and pressed sugar beet pulp on quality fermentation processes was studied in a laboratory experiment. The effect of additive on the quality of fermentation process during maize ensiling was studied in a first model experiment. Preservatives such as formic acid and benzoic acid were added to ensiled maize at the concentration of 1L/t and 1 kg/t, respectively. When benzoic acid was used as a preservative, the pH and the N-NH3/ N total ratio decreased statistically (P<0.05) significantly while the titration acidity increased (P<0.05) in comparison with the control values. The addition of HCOOH to the maize silage reduced the level of acetic acid in dry matter by 11.3% while the overall level of acids decreased by 1.8%. The minimum loss of dry matter (2%) was found in the silage treated with formic acid in comparison with that of the control (11.0%).
Sugar beet pulp silages with benzoic acid or formic acid after 32 days of storage had a better sensuous evaluation than the control silage. The most intensive decrease of pH value was observed after formic acid addition as compared with control silage. The statistically significantly (P<0.05) highest lactic acid content (49.64 ± 0.28) as well as the highest ratio of LA/VFA were found in the sugar beet pulp silage with benzoic acid. Lactic acid constituted the highest percentage (P<0.05) of all fermentation acids in the silage with benzoic acid additive (65.12 ± 0.80). Undesirable butyric acid (BA) was not found in any variant of silages. The positive correlation between the titration acidity and acids sum in dry matter of silage conserved with formic acid was found. The additive of organic acids reduced significantly TA and fermentation acids content. Between the pH value and lactic acid content, no correlation was found.


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