Feeding piglets after weaning remains a challenge for most producers, and the reasons for post-weaning anorexia are many and complex. The general consensus is that weaned pigs do not eat because of radical changes in their feeding behavior, and feed form and composition after weaning. Before weaning, the sow was responsible for feeding piglets at frequent intervals, and communal liquid feeding was, thus, the norm for piglets. After weaning, the piglets are faced not only with a stressful physical and social environment, but also with the decision of when and how much to feed themselves. To make things worse, where water was provided before in conjunction with solid matter in sow’s milk, now the weaned pig needs to distinguish between thirst and hunger and also to realize that these needs must be satisfied via separate media — dry feed and water. A low-quality environment and poor health status certainly do not help an already affected appetite.
But why is ensuring a high feed intake during the early post-weaning period so important? Research has repeatedly demonstrated that low feed intakes during the early post-weaning period severely limit future growth potential, increase temperature and management requirements, intensify morbidity and mortality, and reduce turn over of facilities. The following generic rule may be applied to understand this issue:
For every 100 grams of extra feed intake per day during the first week post-weaning, body weight increases by at least 2 kilograms at the end of the fourth week post-weaning.This has a dramatic effect on overall performance during the growing-finishing period as pigs that barely maintain their weaning weight during the first week may take an extra 10 days to reach market weight compared to pigs that grow at their pre-weaning gain rates (about 200 grams per day) during the same period.
Early-weaned pigs require about 250 grams of dry feed per day during the critical first week post-weaning, to maintain their pre-weaning growth rate. Actual feed intakes, however, rarely exceed 100 grams per day during this period, and this is barely enough to maintain body weight at thermoneutral conditions. Fortunately, progress in nutrition and feeding management has equipped producers with an array of measures to prevent starvation and enhance post-weaning feed intake. All or some of the following are used successfully in profitable operations: