Dr. Leanne Huber of the University of Guelph delivered a technical and practical presentation at the Manitoba Swine Seminar, focusing on precision feeding strategies for modern sows producing larger litters.
Huber, an Associate Professor in the Department of Animal Bio-sciences, leads research in swine nutrition with emphasis on improving productivity and sustainability through precision feeding. She grounded her presentation in one clear reality: today’s sows produce larger litters, and nutrition programs must adapt.
“We know our sows are producing larger litters,” Huber said. “We have to encourage those sows to produce more milk to support those extra piglets.”
Heavier pigs at weaning perform better in the nursery and typically maintain growth advantages through to market. But Huber stressed that milk production capacity develops before farrowing, particularly during the last 30 days of gestation when mammary development accelerates.
Her research showed that feeding higher lysine levels during late gestation improves subsequent milk production. In trials where lysine supply increased during the final 30 days before farrowing, sows produced more milk in weeks two and three of lactation, indicating improved lactation persistency.
Based on modelling and performance data, Huber suggested that lysine intake during late gestation may need to increase by 15 to 20 per cent above current National Research Council (NRC) estimates for gilts.
“The potential for milk production is already developing before farrowing,” she said.
She cautioned that increasing milk production requires a precise lactation feeding program to support those sows once they enter the farrowing room.
Huber compared standard gestation feeding programs to a targeted top-dressing strategy. Most systems feed a fixed amount of a low-protein gestation diet throughout pregnancy, switching to a higher-protein ration only when sows move into the farrowing room. That timing depends on facility logistics rather than biology.
“The timing of the diet switch is based on labour and facility constraints,” Huber said. “It has nothing to do with the underlying biology of the sow.”
Using NRC modelling, she demonstrated that standard gestation feeding oversupplies lysine early in gestation but under supplies it during late gestation, when fetal growth and mammary development drive higher requirements. In one example, late-gestation requirements exceeded the standard supply by 6 grams of lysine per day.
A practical solution is to top-dress the existing gestation diet with a protein source, such as soybean meal, during the final 20 to 30 days of gestation. Adding approximately 230 grams of soybean meal per day supplies the additional lysine needed without excessively increasing energy intake or over-conditioning sows.
In contrast, traditional “bump feeding,” which increases the total gestation ration, often doubles energy supply while failing to meet lysine requirements.
“We may be over-supplying energy and under-supplying lysine,” Huber said.
She shared commercial data from an Ontario producer who adopted top-dressing.

The farm recorded an additional half pig weaned per sow per year, heavier weaning weights and improved finishing performance. Huber noted that management changes occurred simultaneously, so the improvements cannot be attributed solely to top-dressing, but the results remain compelling.
Huber then shifted focus to lactation feeding.
For years, producers restricted feed intake immediately after farrowing to prevent digestive upset. More recent data challenges that practice. Prairie Swine Centre trials compared sows given ad libitum feed access from day one post-farrow with those restricted for the first two days.
Researchers found no evidence of a feed intake “crash” in unrestricted sows. The sows self-regulated intake during the first few days. While early unrestricted feeding did not increase litter size or weaning weights in that study, broader data show that higher overall lactation feed intake correlates strongly with improved milk yield and heavier litters at weaning.
In parity-one sows, higher feed intake during lactation increased milk production and improved subsequent reproductive performance. Sows that maintained high feed intake weaned 1.5 more pigs per litter in the next cycle and showed shorter wean-to-service intervals.
Importantly, low feed intake during the first week of lactation reduced weaning weights even if intake improved later.
“That first week post-farrow is critical,” Huber said.
She outlined practical strategies to increase lactation intake: frequent feeding, fresh feed delivery, maintaining feeder function and considering diet palatants. Brazilian research showed that flavoured feed increased intake by 18 per cent and improved litter growth rates.
Huber also examined diet composition. Energy and lysine demands change dynamically throughout lactation, yet most systems feed a static ration. Her team developed dynamic feeding programs that adjusted lysine-to-energy ratios weekly and by parity. Gilts and multiparous sows responded differently.
Sows receiving parity-specific dynamic diets produced heavier pigs at weaning compared to those on static programs. However, dynamic systems require blending multiple diets and increase feed costs.
For operations without advanced blending systems, Huber suggested targeted top-dressing in the farrowing room, especially for parity-one sows with lower intake but higher nutrient demands.
She closed with three take-home messages: begin supporting milk production in late gestation; maximize feed intake during the first week of lactation; and consider adjusting diet composition to match changing nutrient demands.
“The more those sows eat, the more milk they make,” she said.
Precision feeding, she argued, aligns biology with management and strengthens sow productivity from gestation through the next reproductive cycle. •
— By Harry Siemens