Survival of Listeria monocytogenes in Wilted and Additive-Treated Grass Silage

Table 3 Composition of contaminated silages without additives. Values are means of 6 silos (silos with water locks and capillary tubes were merged).

Silage analyses	200 gDM/kg		430 gDM/kg		540 gDM/kg
	30 days	90 days	30 days	90 days	30 days	90 days	LSD*
DM content (g/kg)	206	201	425	423	536	538	8.3
Water activity (a_w)	0.99	0.97	0.96	0.96	0.95	0.95	0.018
pH	4.90	4.65	5.80	5.53	5.93	5.88	0.057
L. monocytogenes (log cfu/g)	2.3	n d⁺	7.9	n d	6.3	< 2.0*	0.94
Lactic acid (g/kgDM)	70	86	32	44	10	14	1.9
Acetic acid (g/kgDM)	8	11	4	5	4	4	0.5
Butyric acid (g/kgDM)	17	21	0	0	0	0	0.5
Ammonia-N (g/kg N)	99	110	58	82	32	43	2.6

* L. monocytogenes was detected only in 1 (<log2.0/g) out of 6 silos.
⁺ nd = L. monocytogenes not detected; *LSD = least significant difference at p = 0.05.

ISSN: 1751-0147