Interpretive Summary: Dynamic modeling of nutrient use and individual requirements of lactating sows
By Dr. Caitlin Vonderhoe
Nutrient requirements during lactation are highly dependent on feed intake and milk production, which tend to vary between animals. It is common for producers to use a standard diet throughout their lactating sow barn. Unfortunately, this may leave some sows in a negative energy balance, which could potentially negatively affect her subsequent conception. Other sows fed this standard diet may have lower requirements and therefore excrete an excessive amount of nutrients into the environment. A recent study, published by Gauthier et al. in the Journal of Animal Science, “Dynamic modeling of nutrient use and individual requirements of lactating sows” modeled and critically examined the variability of nutrient requirements among individual sows’
Data from two farms were collected and included: sow reproductive and intake parameters, as well as piglet growth performance. The data were modeled to estimate maintenance and milk production costs of each sow and were used to determine nutrient requirements. Specifically, ileal digestible amino acid, metabolizable energy, and mineral requirements, as well as milk production, were estimated using this data. Python-3 software was used to model the data and simulate daily performance—this was subsequently statistically assessed with SAS to determine nutrient requirements for each week of lactation.
In general, sow feed intake, milk energy, and protein output differed between each farm, sow parity, and week of lactation.
This study was able to use the data from individual sows to determine the correlations between performance and nutrient requirements throughout lactation. Approximately 78% of sows entered a negative energy balance, while 22% of sows excreted an excess amount of nutrients into the environment. In this case, it may be beneficial for producers to identify sows in a positive energy balance, and endeavor to improve nutrient intake of the sows in a negative balance. The authors also found significant variation in SID lysine requirements and depended on piglet growth, litter size, and feed intake.
Sow feed intake and milk production significantly affect the nutrient requirements of an animal, and there is a more considerable variation in nutrient requirements of lactating sows compared to growing pigs. As a result, producers may consider using precision feeding practices to meet individual nutrient requirements better to maintain sow welfare and performance.
To view the full article, visit the Journal of Animal Science.