an epidemiological study of listeriosis in dairy cattle

Grass silage
Y N OR (95% CL) p Value
fed 93 761 ? 0.05*
source
home made 89 750 0.3 (0.1-1.3) 0.1
purchased 9 27 2.9 (1.2-6.8) 0.01*
outdoor feeding
fed 77 567 1.7 (0.9-3.0) 0.1
ad libitum 9 50 1.4 (0.6-3.1) 0.5
on the ground 1 18 0.4 (0.0-2.9) 0.5
in complete diet 9 71 0.9 (0.4-2.0) 0.9
in ring feeders 55 352 1.5 (0.9-2.7) 0.14
in troughs 16 157 0.7 (0.4-1.3) 0.25
in hay racks NA
off the field 2 23 0.6 (0.1-2.9) 0.7
indoor feeding
fed 92 750 1.4 (0.2-28.7) 0.8
ad libitum 17 107 1.4 (0.7-2.5) 0.35
at the clamp face 23 158 1.3 (7-2.1) 0.46
on the floor 2 67 0.2 (0.04-0.97) 0.04*
in complete diet 12 89 1.1 (0.6-2.2) 0.8
in ring feeders 53 310 1.9 (1.2-3.1) 0.004*
in troughs 27 242 0.9 (0.5-1.4) 0.6
in hay racks NA
off the field NA
duration of feeding
6 months 52 288 1.78
All year 14 70 1.97 0.03*
Grass silage