In hyperprolific sows with the potential to produce large litters, gestation length will typically last for 3 months, 3 weeks and 3 to 5 days. The more foetuses present, the less room there is for adhesion of the placenta of each individual pig to the uterine wall. To facilitate maximal embryonic development, it is important that the sow is optimally nourished prior to insemination. Also it is important to recognise and minimise stress factors such as fluctuations in environmental temperature, social stress such as fighting and exposure to toxins and infections e.g. PRRS. In hyperprolific sows particularly, these factors have significant negative impact on the forthcoming gestation.
During the last few weeks of gestation, the foetuses grow dramatically. At the same time, glycogen-reserves need to be established! If uterine nutrition is inadequate at this time, the foetuses’ vital organs such as the brain, intestines or lungs may be adversely affected. Even if pigs look normal at birth, they may still be physiologically underdeveloped.