Healthy gut development, prerequisite for weaning success

A lot of of ink has been spilled on how the pre- and postweaning period is determining the future health and performance of piglets. This phase, often home to many challenges and diseases and first use of antimicrobials will need our full nutritional attention and best management practices if we want to reduce further the antimicrobial use and increase sustainability of our business. 

Neonatal piglets are facing many challenges as they did not get sufficient prenatal maternal immunity and among others also have limited energy supply in the body. To overcome this hiccup, Mother Nature provided the newborn piglet with a high permeable epithelium enabling macromolecular passage of immunoglobulins, vitamins, etc. The effective gut closure normally happens within 24hrs after birth and is being modulated by the colostrum supplied by the sow. Colostrum has several functionalities such as maturing and modulating the intestinal tract and its microbiome by specific prebiotic compounds and other bioactive substances. After gut closure the important function of absorbing nutrients and keeping out pathogens can start. The gut barrier development however does not only comprises the epithelial barrier, transport functions and immune system maturation, it also implies the development and the functioning of the enteric nervous system (ENS). The ENS undergoes a number of important developmental changes in early life including the synthesis of neurochemicals and synapse formation. The ENS is functioning separately from the central nervous system however Moeser et al., indicated that the association between the ENS and the higher centres also plays a key role in animal well-being, health, structure and function of the GIT.

The window of opportunity to develop the gut barrier function lasts until several weeks after weaning and coincides with normal weaning age in nature. However modern weaning happens much earlier compromising this development. In addition weaning piglets are stressed around weaning: change from milk to solid feed, new littermates, new environment, etc. These stressors play an important role in the gut barrier functioning. Stress can contribute to higher permeability of the epithelium and leads to the so called ‘leaky gut’. Translocation of pathogens as a consequence can cause intestinal disorders and need for medical intervention. The leaky gut syndrome is a very important contributor to post weaning diarrhea and it takes several weeks before a compromised gut barrier is restored in its original function. However, by applying appropriate early life interventions we are able to steer neonatal gut development, reduce the risk of pathogen translocation and overcome gastro-intestinal disorders such as post-weaning diarrhea without the use of therapeutic ZnO and with no or very limited antibiotic use. 

Successful weaning starts prenatal by proper sow feeding to ensure a smooth farrowing process and giving birth to vital piglets. These piglets will locate the udder more rapidly allowing them to take in colostrum sooner and in higher quantity. In addition, lastborn piglets, often less vital piglets, are condemned to the rear teats producing 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 important 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., recently indicated that getting used to solid feed in a playful way will ‘train the brain’. The author described it as:  “training for the unexpected hypothesis”, in other words making piglets used to new situations in an early phase and therefore reduce stress occurrence later in life. The authors did not see a higher feed intake before weaning, but after weaning piglets ate more and especially earlier, which is important to maintain the villi structure created before weaning.  

An early creep feed such as Babito^® is especially developed to train the piglets to eat and stimulate their exploratory behavior as the product sticks to the nose of the piglet and contains specific corn flakes allowing the piglets to discover the feed in a playful way. Due to its specific composition it will also develop the gut structure (eg. villi formation) and stimulate enzyme secretion to digest plant based raw materials. This will smoothen the transition to a weaning diet and reduce stress. Recently Babito^® has been enriched with the new START+ concept . This concept contains specific components mimicking the prebiotic oligosaccharides present in colostrum of sows. Research in collaboration with universities showed that START+ has a positive effect on gut microbiome, gut structure and gut barrier function (Figure 1) .

At weaning, it is of utmost importance to maintain the created gut structure, the commensal microbiome and a low epithelial permeability. This demands a multifactorial approach focusing on management and nutrition around weaning. Within the nutritional approach the Aim For Zero program was developed: adapted formulation and targeted functional feed ingredients to keep the gut healthy to reduce the dependency of ZnO and antibiotics. From a nutritional point of view it focusses on applying optimal post weaning formulation, aiming to avoid protein fermentation and steering carbohydrate fermentation. This approach needs to be adapted according to the different genetics as this has an important effect on the formulation strategy to follow. The functional feed ingredient concept is aiming at reducing pathogens, disarming endotoxins and maintaining gut barrier integrity. The latter is being accomplished by specific polyphenols with a strong focus on gut integrity (Figure 2).The combination of START+ around weaning with the Aim For Zero concept after weaning has proven in practice to be very beneficial to piglet health and growth. 

Gut barrier development in neonatal piglets is a complex process and needs to be done in a very short period of time. Weaning stress should be avoided as much as possible as it jeopardizes the gut structure. In addition, effective gut integrity improving interventions and a well-balanced formulation will help to prevent a leaky gut and will be a prerequisite for a healthy weaning process.