Gilts were allocated at 55 kg live weight to one of three treatments: 1. 1·4 kg of food daily to service, served at puberty, and 1·4 kg of food daily throughout pregnancy.
2. 1·4 kg of food daily to service, served at the third heat, and 1·4 kg of food daily during pregnancy.
3. 2·3 kg of food daily to service, served at the third heat, and 1·4 kg of food daily during pregnancy.
An attempt was made to encourage early puberty by stimulation using the presence of a boar. Natural service with boars was used on all gilts.
There were no significant differences between the treatments in time taken to reach puberty and the gilts were mated at 77, 97 and 116 kg live weight on Treatments 1, 2, and 3 respectively. The gilts on Treatment 1 had a significantly lower conception rate and a significantly smaller litter size than those on Treatments 2 and 3. However, the average birth weight did not vary significantly among treatments.