Usually we plan the development of broiler breeder males according to the rearing schedule of females, in order to have them matured in a synchronized way and be ready for mixing when the females are sufficiently developed. However, sometimes we need males to develop faster, for instance when spiking males are needed earlier than planned.

Females cannot speed up in their development without creating problems with double yolks, prolapse and peritonitis. Allowing females to develop faster with higher body weights increases and earlier light stimulation will result in more mortality and poor egg production as their reproductive system cannot handle the early development, but males do not have this problem.

It is therefore possible to put males on a program that allows them to develop earlier. The maximum increase that can be realized is approximately 8 weeks, which means that males can reach the developmental stage which is typical for 24 weeks of age already at 16 weeks of age. Earlier development than that is not really possible without creating problems for the birds, a slower development (for instance 4 weeks or 6 weeks earlier) is no problem.

When we want to bring the males earlier in development, we simply draw a body weight line from approximately 10 weeks of age to the required body weight of 24 weeks at the moment we want to have the males ready. So if the body weight at 24 weeks is 3600 gram and we want to bring the males 4 weeks earlier in production, aim at this body weight at 20 weeks of age, with the feed amounts that are accordingly adjusted.

Not only will the males become earlier mature, but due to the less severe feed restriction also the mortality and the uniformity of the males usually will benefit.

This system cannot be applied in a standard production system as the delivery of males and females in different ages creates too many logistic problems, but in situation where an adjustment needs to be made to have enough males ready for spiking at an age earlier than expected, it can be beneficial.