Table 3.

Odds ratio for association of stillborn calves with mastitis pathogens and parity of dairy cows.

Causative Agents of Mastitis	Factor	P	OR	95% C.I.for OR
Escherichia coli	Group of cows	0.006	2.667	1.318	5.397
Mixed microbiota	Group of cows	<0.001	1.630	1.351	1.965
Non-pathogenic Staphylococci	Parity	0.050	0.658	0.433	1.001
Other Gram-negative species	Group of cows	0.036	1.264	1.015	1.573
Other Gram-positive species	Group of cows	<0.001	1.661	1.316	2.096
Other Streptococci	Group of cows	<0.001	2.504	1.566	4.004
Pathogenic Staphylococci	Group of cows	<0.001	2.991	2.027	4.415
Staphylococcus aureus	Group of cows	<0.001	2.905	2.034	4.149
	Parity Herd class	0.049 0.050	0.716 1.278	0.509 1.063	1.008 1.521
Streptococcus agalactiae	Group of cows	<0.001	2.469	1.509	4.037
	Parity	0.048	0.630	0.395	1.004

Groups of cows: 0—healthy cows, 1—cows with the identified mastitis agent indicated in the relevant row of the table. Two categories of parities (parity 1 and parity ≥ 2); herd class (100–200 cows and 201–600 cows); p-value (statistically significant with a p-value < 0.05); OR—odds ratio; 95% C.I. for OR—95% confidence level for odds ratio.