Genetic selection for increased litter sizes has increased the demand for the lactating sow to produce milk. Mammary gland development occurs during three distinct phases: between 90 days of age and puberty, during the last third of gestation, and during lactation[39]. Any interventions aimed at increasing mammary development must be implemented during one of these periods in order to be effective.
We recently found that increasing the dietary amount of the amino acid, lysine between days 90 and 112 of gestation, increased the amount of mammary parenchymal tissue (milk-producing tissue), with the added benefit of increasing piglet birth weight (Farmer, 2022; unpublished data).
Others have shown that piglets from sows fed lysine above estimated ‘requirements’ during late gestation also had greater growth rates during the suckling period[6], indicating greater milk yield by the sow. Clearly, the lysine ‘requirement’ used in our feed formulations is too low to maximize mammary development during late gestation and consequently, milk production in the subsequent lactation period.
Therefore, we plan to determine the amount of dietary lysine needed to maximize these outcomes to improve the milk production potential of sows, the birth weight and growth rates of offspring, and pre-weaning piglet survivability. These data will also improve the accuracy and precision of nutrient requirement models for gestating sows, which will have feed cost benefits.
Generating lysine recommendations that maximize mammary development during late gestation, milk production in the subsequent lactation period, and piglet survivability constitutes an ‘improvement to swine industry practices’.
