Factors influencing the age at puberty
Genetics
- Meishan gilts reach puberty at about 3 to 3.5 months of age as compared to Yorkshire and Landrace at 6 to 7 months of age.
- Crossbred gilts reach puberty about 2 weeks earlier than the average of their parent breeds.
Body weight and composition
- Gilts must reach a certain weight and level of body fat before they can reach puberty.
External or social factors
- Season of birth
- Exposure to boars (pheromones)
- Housing density or number of gilts per pen and space per gilt.
- Transport, mixing with new pen-mates, and relocating to new pen.