The calf stage is a critical period, as newborns are particularly vulnerable to infections of the ruminant digestive system. The development of the ruminant lower gut microbiotaGlossaryView allMicrobiota
A microbiota is the whole of the ecosystem (bacteria, yeast, fungi and viruses) living in a specific environment. Intestinal microbiota was previously called “intestinal flora.” in this calf’s immune transition is crucial to ensuring the calf’s healthy development and optimizing immune function (Du W. et al., 2023).

How is the calf’s immune transition a critical event for the ruminant digestive system?

The calf’s immune transition represents an immune challenge in calves, with potentially major consequences for the health of the ruminant digestive system.

• At birth, immunity is passive, thanks to the antibodies provided by colostrum (Hulbert L.E., Moisá S.J., 2016).
• After two weeks, the calf acquires active immunity by producing its own antibodies and immune cells (Hulbert L.E., Moisá S.J., 2016).

But the calf’s immune transition transition period is very critical for newborn calves because their immune system is immature (Hulbert L.E., Moisá S.J., 2016), making them highly vulnerable to infections of the ruminant digestive system by various intestinal pathogens, putting them at increased risk of mortality and morbidity (Du W. et al., 2023).

Colonization of the ruminant lower gut microbiotaGlossaryView allMicrobiota
A microbiota is the whole of the ecosystem (bacteria, yeast, fungi and viruses) living in a specific environment. Intestinal microbiota was previously called “intestinal flora.” is therefore essential to promote the establishment of the ruminant intestinal barrier function and the maturation of the immune system, and to improve the resistance of newborn calves to these pathologies of the ruminant digestive system (Du W. et al., 2023).

The development of the ruminant lower gut microbiotaGlossaryView allMicrobiota
A microbiota is the whole of the ecosystem (bacteria, yeast, fungi and viruses) living in a specific environment. Intestinal microbiota was previously called “intestinal flora.” in calves is a parameter of intestinal, metabolic and immune health for the ruminant digestive system

Calves rapidly establish a complex microbiota after birth (Du W. et al., 2023). The lower gut microbiota has a significant impact on the host immune system, and its presence early in development can have lasting effects on  lower gut health in adults (Du W. et al., 2023).

• Bifidobacterium, one of the earliest and most abundant bacteria to colonize the neonatal ruminant lower gut, synthesizes polysaccharidesGlossaryView allPolysaccharides
  Succession of several sugars molecules. capable of inhibiting the growth of pathogens, helping to build the intestinal barrier role.
• Lactobacilli increase the total concentration of serum immunoglobulins and can also inhibit the growth of pathogenic bacteria in the ruminant digestive system by lowering the pH and competitive attachment in the lower gut.

The importance of establishing the ruminant lower gut microbiota for short and long-term health has been widely demonstrated (Du W. et al., 2023), so if you would like to learn more about the management of the ruminant lower gut microbiota with probiotics, click here.