Abstract:
The effect of ephemeral fever (EF) on the lactation, pregnancy and fertility of 19 dairy cows was studied. During the febrile reaction milk yields were reduced by an average of 58,7 ± 22 %, depending on the stage of lactation at which the infection was contracted. Ephemeral fever predisposes lactating udders to mastitogenic bacterial infections by deleteriously affecting the leucocytic udder barrier. Delayed oestrus was associated with EF in five out of 14 cows examined.