Healthy gut development, a prerequisite for weaning success

Much ink has been spilled on how the pre- and post-weaning periods determine the future health and performance of piglets. These periods include many challenges and exposure to diseases, often resulting in the first use of antimicrobials. To further reduce the need for antimicrobials, full attention to nutrition and best management practices is needed to increase farm sustainability.

Born without sufficient prenatal maternal immunity and with a limited energy supply in the body, neonatal piglets face many challenges. To overcome this setback, newborn piglets are born with a highly permeable epithelium—enabling the macromolecular passage of immunoglobulins, vitamins, etc. The gut closure normally happens within 24 hours after birth and is regulated by the supply of colostrum. With specific prebiotic compounds and other bioactive substances, colostrum is essential for maturing and modulating the intestinal tract and its microbiome.

After gut closure, the gastrointestinal tract’s important function of absorbing nutrients and keeping out pathogens can start. Gut barrier development does not only comprise of structural properties—development of the epithelial barrier, transport functions, and immune system maturation—it also involves the formation and operation of the enteric nervous system (ENS). The ENS undergoes many crucial changes in early life, including the synthesis of neurochemicals and synapse formation. The ENS functions separately from the central nervous system. However, a study indicated the association between the ENS and the higher centers also plays a key role in animal well-being, health, structure, and function of the gastrointestinal tract (Moeser et al., 2017).

In nature, the window of opportunity to form the gut barrier function lasts for several weeks after weaning and coincides with normal weaning age. However, with modern practices, weaning happens much earlier and compromises this development. In addition, piglets are stressed around weaning: change from sow milk to solid feed, new littermates, new environment, etc. These stressors heavily impact the gut barrier integrity and can contribute to higher permeability of the epithelium, leading to a ‘leaky gut’. A consequence is the translocation of pathogens, causing intestinal disorders that often demand medical intervention. Leaky gut syndrome is a huge contributor to postweaning diarrhea and it can take several weeks for a compromised gut barrier to be restored to its original function. By applying appropriate early-life interventions, neonatal gut development is steered, reducing the risk of pathogen translocation and overcoming gastrointestinal disorders. These outcomes can be achieved without the use of therapeutic ZnO and with no (or very limited) antibiotic use.

To ensure a smooth farrowing process and vital piglets at birth, successful weaning starts prenatally with proper sow feeding. These piglets will locate the udder more rapidly, allowing them to take in colostrum sooner and in higher quantity. In addition, lastborn piglets, often the less vital, are condemned to the rear teats that produce less colostrum and milk. Management strategies, such as split suckling, can help the intake of colostrum by the smaller, more vulnerable piglets. As mentioned earlier, colostrum plays an essential role in the gut closure process, protecting the piglet from pathogen translocation.

Besides good colostrum management, training the piglet to eat solid feed is an excellent way of preparing it for weaning. Middelkoop et al., 2019, indicated that playfully transitioning to solid feed will ‘train the brain’. The author described it as, “training for the unexpected hypothesis”. In other words, make piglets face new situations in an early phase to reduce change-induced stress later in life. The authors did not see higher feed intake before weaning but after weaning piglets ate more and especially started earlier, which is key to maintaining the villi structure created prior to weaning.

An early creep feed, such as Babito^®, is specially designed to train piglets to eat and stimulate exploratory behavior. Babito^® sticks to the nose of the piglet and contains specific corn flakes, helping piglets playfully discover the feed. Due to its unique composition, it also helps develop the gut structure (e.g. villi formation) and stimulates enzyme secretion to digest plant-based raw materials, helping smooth the transition to a weaning diet and reduce stress. Babito^® is enriched with START+, a concept containing specific components that mimic the prebiotic oligosaccharides present in the colostrum of sows. Research done in collaboration with universities showed that START+ has a positive effect on the gut microbiome, gut structure, and gut barrier function (Figure 1).

At weaning, it is of utmost importance to maintain the existing gut structure, the commensal microbiome, and low epithelial permeability. This demands a multifactorial approach, focused on management and nutrition around weaning. With these factors in mind, the Aim For Zero program was developed. This program starts with adapted formulation and targeted functional feed ingredients to preserve gut health. From a nutritional point of view, it focuses on applying an optimal postweaning formulation; aimed to avoid protein fermentation and steer carbohydrate fermentation.

This approach is adapted according to different genetics with appropriate and unique formulation strategies based on breed. The functional feed ingredient concept is aimed at:

The latter is accomplished with a strong focus on gut integrity supported by specific polyphenols (Figure 2). The combination of START+ and Aim For Zero around weaning has proven to be very beneficial to piglet health and growth.

Occurring in a small window, gut barrier development in neonatal piglets is a complex process. To prevent jeopardizing the gut structure, weaning stress should be avoided as much as possible. Therefore it is crucial to look beyond the weaning phase and start with the first critical phase, the suckling phase. Here, a sufficient quantity of high-quality colostrum guides gut closure to create a strong epithelial lining, supporting nutrient absorption and pathogen protection. Next, start feeding a ‘playful’ creep feed shortly after birth. By supporting curiosity and change, it encourages better growth and less mortality. These are the first steps towards healthy gut development and successful weaning.