The Triple Nutritional Challenge of the Post-Weaning Piglet

The transition from sow’s milk to solid feed is one of the most critical periods in a piglet’s life. Weaning combines abrupt dietary, environmental and social changes that often reduce feed intake, disturb intestinal function, and impair digestion. During this adaptation period, newly weaned piglets must efficiently digest and absorb the three main nutrient fractions that drive growth: crude protein, starch, and lipids.

Crude protein (CP) is particularly challenging in the nursery period. The immature digestive system limits secretion and activity of endogenous enzymes, reducing protein digestion efficiency. As a result, part of the dietary protein may escape digestion in the small intestine and reach the hindgut, where microbial fermentation produces metabolites such as short-chain fatty acids, sulfur-containing compounds, aromatic compounds, polyamines and ammonia (Wang et al., 2018). Excessive ammonia can increase intestinal pH and favour the proliferation of potentially pathogenic bacteria linked to post-weaning diarrhoea (Bhandari et al., 2010). Nutritionally, undigested protein also represents lost amino acids that could otherwise support lean tissue deposition and growth.

Starch digestion is also affected. After weaning, endogenous amylase activity decreases before gradually adapting to the cereal-based diet. This temporary limitation may reduce starch hydrolysis, lowering glucose availability for absorption and energy metabolism. The early post-weaning drop in feed intake further compounds this issue, as intestinal development and enzyme secretion are closely linked to nutrient consumption.

Lipid utilization presents a third hurdle. Although fats are dense energy sources, their digestion depends on emulsification, lipase activity, micelle formation, and intestinal absorption. In young piglets, bile salt production and digestive secretions are still developing, which can limit fat digestion and reduce the actual energy contribution of dietary lipids.

Digestion and absorption are closely interconnected. Even when nutrients are adequately digested, post-weaning changes in intestinal morphology, including villus atrophy and reduced absorptive surface area, can compromise nutrient uptake. Nutritional strategies for nursery diets should therefore address not only digestibility, but also absorption and utilization.

For this reason, nutritionists increasingly evaluate tools that support both digestive and absorptive functions. Exogenous enzymes, such as proteases and amylases, may help compensate for temporary deficits in endogenous enzyme production, while technologies supporting lipid digestion and nutrient absorption can improve nutrient recovery from the diet. Overcoming this triple challenge remains key to supporting gut health, feed efficiency and growth performance after weaning.