sow reproductive cycle feeding

Phase feeding has been embraced by the wean-to-finish sector where six, eight or even 10 diet changes are standard practice today. Perhaps that’s because it’s easy to see the physical changes in a growing pig and connect the logic to making nutrient adjustments.


The breeding herd presents several more challenges. Genetics, parity, litter size, body condition all influence the sow’s dietary needs. Customizing feed delivery can be a challenge depending on herd size, housing arrangement, equipment and staffing. But phase feeding in both gestation and lactation is a critical step toward more effectively managing the reproductive cycle and boosting sow longevity.


The bottom line in phase feeding is to meet the animal’s nutrient needs. “To provide the sow less when it needs less and more when it needs more,” says Sam Baidoo, associate professor at the University of Minnesota Southern Research and Outreach Center, Waseca, Minnesota. Baidoo and his graduate students are in the process of researching phase feeding in gestation and lactation.


Too often a single diet with constant amino acid and energy levels is fed throughout the gestation period, Baidoo notes. Consequently, some sows will be underfed and some will be overfed. That’s a problem from a cost and feed efficiency standpoint, but it’s also a problem for the growth and health of the litter as well as the health and functionality of the sow.


“With sows, the production cycle is connected,” Baidoo points out.


“You start with a gilt. It’s bred and goes through gestation, farrowing, lactation and then moves through the cycle again. It’s all connected; if there’s a shortage or an effect in one stage, it will show up in the next one.”


Feed for a Purpose

“In both gestation and lactation, we feed sows for a purpose,” says Baidoo. “In gestation, the purpose is to optimize embryo survival and growth, develop the sow’s milk production abilities and optimize body condition. In lactation, it’s to maximize milk production, help piglets grow and maintain sow body condition in preparation for the next cycle and sow longevity.”


In response to today’s larger, leaner, more productive sows the National Research Council (NRC 2012) increased the gestation energy requirement by 10 percent over NRC (1998), but that’s just to accommodate body maintenance. A sow’s nutritional requirements increase significantly from early to late gestation.


The priority during the first 4 weeks is to maximize survival of quality embryos. The nutritional demands of the sow are low because the body’s response to pregnancy is minimal. At 5 to 11 weeks, the fetuses develop and grow, the sow builds body weight and mammary cell development begins. The last 5 weeks of gestation is when fetal growth, mammary development and sow body condition kicks into high gear. (See graphic below.) In fact, fetal weight increases by five-fold and mammary protein content increases by 27-fold during the last 4 to 6 weeks of gestation.


Naturally it’s important to increase the amount of feed that a sow receives as piglets grow regardless if that’s in the gestation or lactation period. “It’s not just about pounds of feed,” Baidoo says. “We need to think more about nutrient density of feed.”


Research shows that a sow’s energy requirement increases by 25 percent to 35 percent from early to late gestation. So, if the diet remains constant, a negative energy balance in late-gestation is likely, which means piglet birth weights, sow condition and milk production could suffer. At the same time, too much energy (or too much feed) can produce a fat sow, which will cause feed intake problems in lactation.


Lysine needs increases about two-fold during the late-gestation period. For example, research shows that sows need higher protein levels beginning on day 69 of gestation. Providing higher levels prior to that would produce no benefit and simply increase cost. Matching the need with supply provides the added advantage of reducing nitrogen excretion in manure.


Target Three Phases

Baidoo recommends dividing both gestation and lactation into three phases. For gestation that would be 0 to 49 days, 50 to 84 days and 85 to 110/115 days. The overall lysine requirement during gestation is 0.6 percent, but feeding levels of 0.4 percent, 0.6 percent and 0.8 percent in the respective phases, better meets the sow’s nutrient
needs. Baidoo adds that the same pattern applies to other nutrients, including crucial amino acids such as threonine, tryptophan, methionine and isoleucine.


“In the week following farrowing, piglets don’t demand that much milk,” Baidoo says. “But as piglets grow, milk production peaks around 7 to 18 days. Nutrient requirements will be extremely high, and we don’t want the sow to utilize body tissue to produce milk.”


Divide lactation into three phases regardless if the weaning age is 18 days or 28 days. For example, the breakout could be 0 to 7 days, 8 to 14 days and 15 to 21 days. For the 1 percent lysine lactation diet requirement, the phase-feeding application would be 0.8 percent in the first phase, followed by 1 percent and 1.2 percent respectively.


Prioritize the Individual

Of course these recommendations are not absolute. “The point is that not all sows are the same, and they should be treated accordingly” Baidoo says. “Any sow-feeding program has to start with the genetics supplier’s recommendations, but the phase-feeding philosophy is universally applicable.”


Many other factors influence a sow’s dietary needs. There’s the parity factor, with Parity 1, and to some extent Parity 2, sows needing higher nutrient levels than older sows because they are still growing. There’s the litter factor, a sow with 12 pigs requires more feed and nutrients than a sow with 10 pigs. And there’s the body condition factor. For a sow with a body condition score of 1 or 2 the first priority is to feed to recover body stores.


Applying phase feeding to the breeding herd can be a challenge, but It starts with knowing the body makeup of the sow, specifically weight and backfat. “I know that producers will not weigh every sow, but they need to weigh some sows sometimes— preferrably upon entering and leaving the farrowing room,” Baidoo says. Backfat also should be measured periodically.


More practical options are to routinely score sow body condition, whether that means visual scoring, using a caliper or a tape measure. There’s an abundance of guidance available, including within the Pork Quality Assurance program.


Electronic sow feeding (ESF) systems and their ability to program settings for individual sows make phase feeding easier in gestation. “Provided you’re able to train the animals and manage the system,” Baidoo adds. “It requires more attention than individual stalls.”


Top dressing feed for sows in individual stalls is an option. An all-in/all-out farrowing room also helps with phase feeding. Because the sows are in the same production phase at the same time, the whole room can receive the same phase diet. Another prospect, if the feeding system has two hoppers, is to have a high-nutrient diet and a low-nutrient diet and blend the feed offering according to the animal’s need.


Baidoo is an advocate of feeding lactating sows two or preferably three times a day to pique the animal’s interest and stimulate consumption. “Today’s hyper-prolific sows are lean, which is somewhat a selection against appetite, so whatever we can do to increase feed intake is beneficial,” he adds.


Remember, the goal in the breeding herd is to increase sow longevity, litter size and weaning weight. “If we are able to do these three things, we’ve won,” Baidoo says, “and phase feeding can help.”


Frank’s Note

Whether a weaned pig is destined for grow/finish or the breeding herd, the production process is a series of interconnected moving parts. Genetics, nutrition, health, facilities, management and much more, all affect the outcome. Actions or events that occur in one stage—good or bad—will impact the animal in the next.


The breeding herd is a prime example of that kind of production flow. Gilt preparation establishes the foundation for reproductive success. Once the gilt enters the breeding herd, breeding and gestation management flows into the farrowing room. There the goal is to get the most high-quality pigs out the door without jeopardizing the sow’s body condition. The interactions within the farrowing room influence the sow’s next reproductive cycle, and so it continues.


With today’s larger, leaner sows producing more and larger piglets, it’s logical that some management strategies need an adjustment, such as phase feeding sows to better meet their needs. Phase feeding throughout gestation and lactation not only benefits sow productivity, but also the animal’s well-being and longevity. On the cost side, the producer maximizes his feed dollar, which boosts his opportunity for profit.


Farmweld takes the same approach in designing and manufacturing our products. Our commitment to durable materials and high-quality manufacturing minimizes maintenance needs as well as operation costs for producers. Designing products for efficient and easy installation ensures the job is done right and on time. Our new A-Crate™ design maximizes the room available to the nursing sow without robbing alley space. Workers have easy access to the sow and litter, making piglet processing, daily observations and animal care efficient.


It all adds up to sow comfort, health and well-being, as well as more piglets that grow into full-value market hogs.


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.


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