When it comes to nutrition, an abrupt change in the piglet’s digestive system happens when transitioning from milk to solid food. During the weaning period, gut bacteria and digestive enzymes are not fully developed, the intestinal barrier is weak, and the immune system is. Pathogens, such as enterotoxigenic E. coli, can take advantage of the piglet’s compromised situation, proliferate rapidly in the intestinal tract, and cause scours. As a highly contagious condition, scouring in weaned piglets is a costly and significant health concern for the swine industry
This issue commonly occurs in pigs weaned between 14 and 28 days of age. It is caused by several factors, including weaning sociological stress, nutrition, and environment all affecting digestive health. With that in mind, weaned piglets can eat and digest good amounts of solid food in the post-weaning period if they receive the right ingredients and nutrients, as well as kept in the right environmental conditions. The following nutritional strategies can help to improve gut health and reduce the incidence of scours at weaning time.
Protein choice
Proteins of low digestibility are more likely to be fermented by pathogens in the gut. The amount of protein that can be fermented in the large intestine should be minimized to reduce the risk of diarrhea.
Instead, inclusion of high-quality, highly digestible protein sources improve pigs’ post-weaning performance. These can include milk by-products such as skim milk and whey concentrate, as well as processed soy proteins with low anti-nutritional factors, which have been shown to increase feed intake in piglets. Milk proteins also contain several bioactive compounds with many potential health benefits. Bioactive compounds consist of growth factors that are present in milk to promote the development of the neonatal gut.
Carbohydrate choice
The pig intestinal tract harbours a diverse population of bacteria, which provide important protective effects against pathogens. These bacteria also carry out many metabolic functions including digestion of plant carbohydrates (fibres) that are otherwise undigestible by digestive enzymes.
Piglets must be fed an optimum level of non-digestible but fermentable carbohydrates (soluble fibre). Beneficial bacteria, such as lactobacillus, can break down carbohydrates as the main energy source for their maintenance and growth. This carbohydrate fermentation process produces short-chain fatty acids (SCFA) – mainly acetate, propionate, and butyrate. SCFA reduce the pH in the digestive tract, which results in fewer undesirable bacteria in the gut. SCFA benefit the pig, providing an additional source of energy, supressing potential pathogen growth, and inhibiting inflammation
Fat choice
Nursery pigs’ ability to digest fat are lower than those of growing pigs. The lower activity of pancreatic enzymes, particularly lipase, after weaning is the main cause of this condition.
Polyunsaturated fatty acids are the preferred fat source for young pigs. Vegetable oils are more digestible than animal fats. However, extracted oils are not bound to any cellular material. As such, free fat can form a layer in the stomach, causing a reduction in feed intake via changes in satiety signaling. Fat contained within raw materials has a higher proportion of bound and less free fat. In our trials, replacing free fat with bound fat has resulted in linear improvements in pig performance suggesting that fat type can influence satiety signaling and feed intake.

Enzyme choice
Insufficient enzyme production results in incomplete digestion, excess nutrient flow to the hind gut, and pathogenic bacteria overgrow. Adding exogenous enzymes to the young pigs’ diet reduces the viscosity of the digesta and provides an opportunity to overcome the animals’ limitation in enzymatic digestion.
Different types of enzymes—mainly xylanases, phytases, mannanases, and proteases—are available on the market, each working on specific substrates. The effects of enzymes are more prominent when diets are formulated below animal requirements or when pigs are exposed to health or environmental challenges.
Feed additives
Due to legislation moving to limit the use of antibiotics in animal husbandry, industry researchers have tested the efficacy of several non-medicated feed additives to support pigs in their defense against pathogenic bacteria. The scientific community and producers have devoted the most attention to fermentation derivatives, essential oils (plant extracts), and organic acids.
Fermentation products: Specific fermentation products offer health benefits to pigs, such as providing nutrients, preventing pathogen adhesion to host cells, interacting with host immune systems, and affecting gut structure (such as Diamond V® SynGenX®)..
Phytogenic additives: Selected plant extracts (essential oils), dried spices, and herbs have anti-inflammatory and antibacterial effects. They can also increase sensorial stimulation, palatability, and encourage early feed intake which is critical in the post-weaning period (such as Delacon™ Products). .
Organic acids: Organic acids lower the pH in the pig’s digestive tract. They also offer the following benefits:
· enhance the digestibility of proteins and the absorption of minerals
· improve the shelf-life, taste, and smell of the feed
· enhance palatability and increase feed intake
· promote the development of gut membrane cells
· have antimicrobial properties
Feed processing conditions
Physical (e.g. grinding) and thermal treatments (e.g. starch gelatinization) of feed prior to animal consumption have many nutritional benefits including increased nutrient availability, improved nutrient utilization efficiency, and inactivation of anti-nutritional factors such as trypsin inhibitors. Anti-nutritional factors reduce nutrient absorption and cause allergic reactions in the gut. The pelleting process also reduces pathogen exposure.
Conclusions
Producers should devote special attention to the weaning period in pigs to manage potential health problems. A high-quality starter feed supports digestive health during this period. Such diets support a healthy gut through careful selection of highly digestible ingredients and by reducing the negative effects of protein fermentation in the pig gut.
The inclusion of moderately fermentable fibres, together with research-proven additives, reduces the growth of harmful bacteria and the incidence of intestinal disorders in pigs. Since pigs typically experience a drastic reduction in feed intake during weaning, producers should choose highly palatable and digestible feed ingredients to enhance intake and digestibility for the newly weaned piglet. •
— By Kathryn Price, PhD,
Swine Nutritionist, Cargill