Spiking, the periodical addition and/or replacement of males during the production period, can be an effective way to increase the level of fertility at an later age of the flock. However, spiking brings a bio-security risk as well, and when not practiced correctly, it's effect can be limited or zero.

When spiking is done, several factors have to be considered:

- Spiking should be planned way ahead, actually before a real problem occurs in the flock. This means that a system should be in place where routiniously spiking can be done. If spiking is not done routiniously, the risk of errors and mistakes is present.
- Spike only with males of a known health status, and monitor the health status of the new males early enough to make a decision on if to use them.
- Spike with males that are old and developed enough to have a fair chance to get a top position in the hierarchy. When males are too young or too less developed, they will not become dominant enough to mate. Young males should be minimum 26 weeks before used for spiking.
- Add at least 25-30% of new males, to have enough males availalbe for breaking the hierarchy of the existing males. Preferably remove the bigger dominant males from the flock before adding new males.
- When extra males are reared to use for spiking, make sure that the total density of the males in rearing doesnt exceed the limits, and that the extra males are removed early enough to prevent problems with early agressiveness of males towards females.
- Place new males early in the evening or late in the afternoon, so they have the night to get adjusted to the new environment. Make sure that during the first days enough feed is given to the males to allow the new males to start.