Problems in weaned piglets are rarely caused by a single factor. Nutrition shifts from sow’s milk to solid feed, the environment changes from the farrowing room to the nursery, and the social group changes from familiar pen-mates to a mixed group. These three stresses occur together, and the gut is often the first organ to run into trouble. Pig farms are familiar with “gradual transition,” but interpreting it as “taking longer to switch feed” addresses only half the issue. What truly determines success during the first two weeks after weaning is the “foundation” established by creep feeding before weaning and the “pace” set during the first few days after weaning.
The goal of creep feeding is not “how much feed the piglets consume,” but to build their gut’s adaptation to and familiarity with solid feed. Starting at around 7 days of age, introduce the feed by mixing it into a paste and applying it to the piglets’ mouths or the sow’s teats. Use their imitative behavior to encourage feeding, and offer it 4 to 6 times a day. The target is for each piglet to consume an average of 50 to 100 grams of creep feed per day before weaning. This amount may not seem large, but the stimulation it provides to the intestinal epithelium is the foundation for a smooth transition later. There is also a more concrete industry benchmark: when weaned at 21 days of age, a total feed intake of 400 grams allows the intestinal surface to develop relatively fully before the complete transition to solid feed; an intake of 600 grams at weaning at 25 days of age is considered an ideal level and can significantly reduce post-weaning diarrhea. For piglets that have not been properly creep-fed, the gut is almost “starting from scratch” when it encounters solid feed after weaning. By then, the risks of diarrhea and weight loss are already elevated, no matter how gradual the feed transition is.
After weaning, the approach is “stabilize first, then change feed.” Continue feeding creep feed for 1 to 2 weeks after weaning so piglets can first settle into a familiar taste and digestive profile. Then gradually transition to nursery feed at ratios of 20%, 40%, 60%, 80%, and 100%, over a transition period of at least 7 days. The purpose of this gradual progression is to allow the gut microbiota to adjust as the available substrates change, rather than suddenly removing all the old nutrient sources on a single day. Reducing sow’s milk and increasing creep feed for 2 days before weaning, then continuing to feed creep feed for 3 to 5 days after weaning before starting the transition to nursery feed, is another approach that fits with this process. Both approaches share the same principle: creep feed continues to serve as a “buffer feed” for a period after weaning, rather than being replaced by nursery feed on the day of weaning.
Environmental management also plays a part in the transition. At weaning, follow the “remove the sow, leave the piglets” approach, keeping piglets in their original pen for 3 to 5 days to reduce anxiety caused by sudden environmental changes. Maintain the temperature in the nursery at 26 to 28℃, lowering it by 1 to 2℃ each week during the first 2 weeks after weaning, until it stabilizes at 22 to 24℃. Keep humidity at 60% to 65%. These figures and the feed-change schedule are two sides of the same logic: feed changes reduce nutritional stress, while the environment and original pen reduce environmental and social stress. If either is managed in isolation without the other, the weaning syndrome will still emerge at the weakest link. The “gradual” nature of the weaning transition essentially means staggering the three types of stress over time, not simply slowing the pace in the nutritional dimension.