Both maintenance requirements and requirements for weight gain must be included when calculating the requirements for young and growing horses.

Scientists in the Netherlands have developed a system based on the physiology of growth for calculating the energy requirements of young horses, where breed and blood types may be included as parameters in the equations. In the PC-Horse program we have defined two levels of energy requirements for young horses in order to cater for differences in the rate of gain which is advocated under different conditions.

When "Rapid growth rate" is selected, the horse is given a 20% higher energy allowance than when "Moderate growth rate" is selected. Rapid growth rate is recommended for horses that are put into training at an early age as well as for horses that are raised in groups and have access to lots of exercise. Further increases in energy supplies may be provided for by selecting the "moderate exercise" options within the program.

Irrespective of the target for growth rate that is selected, it is impotant to monitor the body condition of the horse and adjust feeding levels accordingly. The program contains a standard growth curve which can be used to monitor the development of young horses. The following table may also help in monitoring the growth and development of young horses.

Growth of young horses as percentage of adult body weight