an epidemiological study of listeriosis in dairy cattle

Cases of Listeriosis in beef cattle and sheep were associated with an increased
risk of reporting cases of Listeriosis with nervous signs. Controlling moles in fields was
associated with a decreased risk of disease (OR 0.4, 95% CL 0.1-0.9) (Table 4. 6).
No changes in the results were observed after the removal of herd size from the
model but maize silage feeding was associated with an increased risk of reporting cases
of nervous signs (OR 2.9, 95% CL 1.3-6.6) (Table 4. 6) after the removal of herd size
and cases of Listeriosis in beef cattle from the data set.
Table 4. 6. The multivariate relationship between farming practices and cases of
nervous signs.
Number of observations=603 OR 95% CL p Value
cases of Listeriosis in beef cattle 5.2 1.1-25.5 0.04
cases of Listeriosis in Sheep 4.9 1.3-18.9 0.02
controlling moles
Number of observations=715
0.4 0.1-0.9 0.04
@
maize silage feeding 2.9 1.3-6.6 0.01
OR adjusted odds ratio, @ after the exclusion of herd size and cases of Listeriosis in beef cattle.
The results obtained using the model for each different outcome variables were
remarkably consistent. 14 variables were associated with the outcome variables. 12 of
them were associated with an increased risk of disease. Cases of Listeriosis in beef
cattle and sheep were found to be consistently associated with all outcome variables, the
use of a mower conditioner in preparation of grass silage, feeding grass silage in ring
feeders were also consistently associated with the outcome variables with the exception
of nervous signs. Three predictor variables were associated with three different outcome
variables; preserving grass silage as big bales (associated with overall cases, winter
cases and silage eye), maize silage feeding (associated with overall cases, milking cows
and nervous signs) and not storing manure (associated with overall, milking cows and