One thing is certain, within a sow herd there is constant change. Simply by the fact that a sow moves from one parity to the next brings forth a change. Small changes in litter size can have a big impact on the lactation demands placed on a sow. Appetite, feed nutrient density and delivery in both gestation and lactation can influence the female’s body condition and subsequent reproductive cycles and litters.


The goal within the breeding herd is to maximize productivity and longevity by minimizing wide fluctuations in body condition from one reproductive cycle to the next. That’s a tall order.


While ongoing genetic selection has led to high-lean, fast growing progeny, it also produced leaner sows with lower appetites.


This is a concern in late gestation when sows need to provide sufficient nutrients to support fetal and mammary growth, as well as during lactation when significant sow weight loss can negatively impact subsequent farrowing rate, litter size and litter quality. You can’t afford to underfeed sows, but there’s also a downside to overfeeding, both from a productivity and cost standpoint.

Late-gestation Feeding

There are almost as many ways to feed sows as there are types of sows. The important point is to find what works best for your herd but also to be willing to make changes as needed.


One of the methods focused on improving reproduction is bump feeding, which increases daily feed intake in late gestation.


Some producers embrace this strategy, others do not, yet others haven’t tried it. Past research suggests that bump feeding improves piglet birth weight in gilts but generally not in sows. This is likely because the bred-gilt is still maturing and continues to have greater nutrient demands.


“Research also has shown that increasing feed intake in the last week of gestation increased colostrum production,” points out Mark Knauer, swine reproductive specialist at North Carolina State University. “Simply, more nutrients are available to the sow to use towards colostrum production.”


That fact drove Knauer to conduct a study to look at the effect of bump feeding on piglet quality. “Colostrum is vital to getting piglets off to a strong, healthy start,” he adds. “So, strategies that increase colostrum production should help minimize pre-weaning mortality.”


Knauer set up the study, in collaboration with the North Carolina Department of Agriculture Tidewater Research Station, and randomly sorted 67 Parity-2 Landrace/Large White sows into one of two feeding groups. One group received 4 pounds of feed per day from day 100 of gestation to farrowing, while the other group received 6 pounds. Diets were formulated to 0.68 percent total lysine and 1,354 kcal of metabolizable energy per pound. All other nutrients met or exceeded National Research Council 2012 requirements for swine.


Sows were housed in individual gestation stalls with natural ventilation and ad libitum access to water. They farrowed in late June 2015. Piglets were identified and weighed within 1 day of birth and at 21 days of age. All reproductive traits were calculated as those of the biological dam.


Piglet Results

According to the study, bump feeding in late gestation did not impact total number of piglets born, total litter birth weight, average piglet birth weight or birth weight coefficient of variation when compared to sows fed 4 pounds a day.


However, benefits surfaced at weaning. Bump feeding improved the weaned litter size, litter weaning weight, average weaning weight, weaning weight coefficient of variation and piglet survival. Add it all up, and the bump feeding treatment tended to wean more quality weaned piglets— those weighing more than 7 pounds— compared to sows fed 4 pounds a day, Knauer says.


Sow Results

Knauer monitored sow body condition throughout gestation and lactation using the body condition caliper positioned at the last rib. Sow caliper scores of 9-11, 12-15 and 16-18 correspond to traditional visual body condition scores (a 1 to 5 scale) of 2, 3 and 4 respectively.


“On average, sows lost body condition from day 100 of gestation to farrowing and from farrowing to weaning,” Knauer says. “However, sows that were bump fed lost numerically less body condition from day 100 of gestation to farrowing and significantly less from day 100 of gestation to weaning.”


“Sows that were bump fed lost numerically less body condition from day 100 of gestation to farrowing and significantly less from day 100 of gestation to weaning,” Knauer says.


Take-home Message

Even though the current study suggests that bump feeding in late gestation does not increase piglet birth weight in multiparous sows, it can improve sow body condition as well as the number of quality weaned piglets.


More quality pigs at weaning means more quality pigs move through the grow/finish phase. “The relationship between piglet quality and finishing performance is clear,” Knauer says. “Greater piglet quality reduces wean-to-finish mortality and improves growth.”


Past studies have focused on a 25-day bump, increasing feed on day 90 of gestation to farrowing. Knauer evaluated a 15-day bump, which tightened up the time commitment and cost. “A 7- to 10-day bump, starting on day 105 of gestation and on to farrowing, may be sufficient,” he adds.


The strategy is easy enough to implement. “Everyone should consider applying bump feeding, unless your sows are over conditioned,” Knauer says. “The important point is that the producer must have quality labor who will adjust feeders up at the right time and adjust them down again before the next group of sows comes into the room.”


Establish Body Condition Targets

Optimal body condition is key to sow productivity and longevity. That requires personnel who are committed to accurately assessing the sow’s body condition and then making the necessary feeding adjustments.


“There are tools to help optimize your sow herd body condition,” says Mark Knauer, North Carolina State University. “The point is to find one that you like, be sure your personnel are trained and that it’s used.”


The traditional visual body scoring system uses a 1-to-5 scale, where 1 is excessively thin, 3 is ideal and 5 is  excessively fat. However, because the score is somewhat subjective, the results can vary, so training is critical. Free posters are available through the Pork Store at


Kansas State University developed a method using a rear flank-to-flank measurement taken with a cloth tape measure to estimate body weight. The equation = 26.85 x the flank measurement (in inches) = sow weight (in pounds). The weight is used with an ultrasound backfat measurement to estimate feed intake through the Gestation Feeding Guidelines. Go to under “Gestation Feeding Tools.”


North Carolina State University researchers designed the Sow Body Condition Caliper, which quantifies the sow’s topline as a representation of the amount of fat and muscle it’s carrying. Placed across the sow’s topline at the last rib, the caliper provides a reading of “thin, ideal or fat”. “It takes about 5 seconds,” says Knauer. You can see it in action at For a free caliper, email Knauer at


Frank’s Note

The sow is the engine of the pork production system as it is responsible for the output, whether you’re in the business of supplying weaned pigs or market hogs. There are scores of inputs that influence the sow’s output— genetics, feeding regimens, equipment, management, health—just to name a few. Equipment is one such input that may remain in place longer than its useful life. Specifically, it may no longer fit today’s larger, leaner and more productive sows.


Keeping sows fed and comfortable is important throughout their productive life, whether that’s in the farrowing room or the gestation house. It involves a multi-pronged approach. The feed delivery system has to ensure that the correct amount of feed is available; the feeder must allow the sow to eat comfortably; the diet has to deliver the correct nutrients effectively and efficiently; and the management must ensure that each sow is in proper condition to accommodate the current and future litters.


Farmweld offers a range of products to accommodate the changing needs of today’s pigs from the gestating sow to the market hog. Whether the need is for gating, flooring systems, farrowing crates, piglet creep areas, feeders or waterers, Farmweld provides guidance and service to ensure your system keeps running smoothly.


The quality of our materials, manufacturing and personnel is priority one. You can rest assured that Farmweld products are durable and designed to stand up to the rigors of today’s larger hogs, which is not only a good investment but also provides a safer environment for the animals and workers.


If you have questions, give us a call at 1-800-EAT-PORK (328-7675) or use the contact form or LiveChat on our website.


Frank Brummer, President, Farmweld, Inc.


Full Gestation Feeding Story

Our equipment specialists are ready to answer any and all of your questions.