an epidemiological study of listeriosis in dairy cattle

a) Type of forages: Feeding maize silage (OR 1.97, CL 1.17-3.32) and grass silage (OR
not calculated) was associated with an increased risk of reporting disease (Table 3. 14).
b) Source of forages: Purchased grass silage was associated with an increased risk of
disease (OR 2.62, CL 1.00-6.61) (Table 3. 14).
c) Methods of feeding forages;
1) indoor feeding: Feeding grass silage (OR 2.55, CL 1.51-4.32), maize silage (OR
6.37, CL 2.42-17.19) and hay (OR 4.86, CL 2.02-11.97) in ring feeders was positively
associated with disease. Feeding maize silage ad libitum was also found to increase the
risk of reporting disease (OR 3.57, CL 0.96-12.74). Feeding hay on the floor was
negatively associated with disease (OR 0.0, CL 0.0-0.95) (Table 3. 14).
(iii) Making forage crops:
a) Type of harvesters: Using a mower conditioner for making grass silage was
associated with an increased risk of disease (OR 1.91, CL 1.10-3.35) (Table 3. 14).
b) Storage: Preserving grass silage as big bales (OR 2.00, CL 1.13-3.57) and storing
hay outside covered (OR 6.86, CL 1.22-35.41) were found to increase the risk of
reporting disease (Table 3. 14).
c) Analysis of forages: There was an association between increasing pH and increasing
risk of disease reported in winter months, as the pH value increased the risk of reporting
disease also increased (Table 3. 13).
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