7.6.2 One Day before vaccination

* Determination of drinking water consumption

Four hours after reconstitution of the freeze-dried vaccine its viability starts to decline gradually. Therefore, the vaccination needs to be completed within that time. However, this 4-hour-period should not be shortened significantly to ensure that each pig took the opportunity to drink the required amount of the vaccine. Consequently, the consumption of drinking water over a four-hour period needs to be determined for each group of animal prior to vaccination. The water con­sumption of the animals varies considerably depending on age, weight, level of perform­ance, and environmental temperature. For example a temperature rise from 20°C to 30°C can already cause the water require­ments of the pigs to double.

An assessment of the consumption of drinking water should be carried out 24 hours prior to the vaccination, at the same time of day as the vaccine will be administered on the following day.

The following rule-of-thumb figures (see Table 7.6.2a) can serve as a rough guide for the assessment of the consumption of drinking water. They cannot, however, replace the actual measurement of water intake for each individual animal group, since consumption can vary too widely between groups and can depend on the time of day.

Table 7.6.2 a
Rule-of-thumb figures for the assessment of the drinking water consumption within four hours.

The volume of water as measured for each group of animal represents the volume of water into which the necessary number of vaccine doses has to be mixed!

When using proportioners it should be ensured that the concentrated stock solution in the reservoir of the device is used up after four hours.