NUTRITION ▶▶▶
Improving microbiota while preventing inflammation
Gut health is multi-factorial and complex and depends on the environment, farm management, feed and housing changes. For pork producers, it is a major concern due to its impact on growth performance, animal welfare, economic sustainability and consumer concerns. With use of antibiotics being challenged, the development of alternatives is a must.
BY PAULINE POURTAU, BUSINESS DEVELOPER, WISIUM T
he intestine is the largest interface between an ani- mal and its environment. An intact intestinal barrier is thus essential in maintaining gut health and pre- venting tissue injury and several diseases. The intes-
tinal barrier is formed by enterocyte membranes, tight junc- tions, secreted mucus and immunologic factors, such as tissue macrophages. Dysfunction of this barrier can be caused by different types of stress (e.g., physiological, pathological, psychological, phar- macological) and can lead to increased intestinal permeabili- ty. Increased permeability to endotoxins, a component of the walls of Gram-negative bacteria, causes local or systemic in- flammatory reactions, or both. The immune response can then promote more serious conditions. Hence, assessing barrier integrity is of the utmost importance. The gut microflora is an integral part of the digestive system, which is colonised by an abundant and taxonomically diverse microbial community. Because each species of organism in the intestine has different metabolic capabilities, the relative proportion of different species of organisms changes in re- sponse to a variety of factors including age, diet composition, rearing environment and possibly genotype. To avoid the overgrowth of pathogenic bacteria in the gut leading to dis- eases, maintaining a well-balanced microflora is also essential.
Piglet weaning Intensive piglet breeding generates critical periods where
30 ▶PIG PROGRESS | Volume 36, No. 8, 2020
gut health is highly challenged, including the modification of the gut microflora leading to a higher risk of overgrowth of intestinal pathogenic bacteria. At weaning, piglets face multi-factorial stresses and challenges in a short time: • Adaptation to the feed intake: One of the main tar- gets for farmers is to ensure that piglets eat properly after weaning. The longer they go without eating at weaning, the higher the risk of diarrhoea. The drop in feed intake is likely to cause difficulties achieving growth requirements, due to reduction of the villi height and thus nutrient ab- sorption area, and to mobilisation of fat and muscle reserves.
• Adaptation to the feed distribution: Piglets need to move from suckling milk at the sow to a solid feed.
• Feed composition changes: Piglets’ feed changes from milk containing lactose to a prestarter feed containing mainly plant-based raw materials (with new nutrients as starch for example).
• Adaptation to a new environment: Piglets are separat- ed from the mother and move from a farrowing crate to a post-weaning pen, with possible variation of the microflora present in the environment.
All those changes require physiological and immunological adaptations that are non-visible. For example, weaning pre- sents the first encounter between piglets and some new raw materials. Consequently, this creates a risk of a gut microbio- ta imbalance involving diarrhoea and a loss of performance. That is why it is important to pay attention to the modulation of the digestive microflora. Furthermore, animals have to adapt their enzymatic system in order to digest these new raw materials, which is an im- portant physiological change. At first, the piglet’s organs will consider new feed as an antigen. Piglets also have to adapt their immune system in order to accept this new feed. As 70–80% of the immune cells are located in the gut, that adaptation can generate local in- flammation and oxidative stress. In contact with antigens, macrophages induce the production of pro-inflammatory
PHOTO: WISIUM/SHUTTERSTOCK
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