Meal timing is emerging as an important factor in nutrition, yet its role in livestock health, performance and gut microbiome remains largely unexplored.

• When we eat matters: nutrition research increasingly shows that meal timing can influence metabolism almost as much as what we eat.
• Livestock chronobiology remains largely unexplored: pigs, cattle and poultry share with humans the same circadian architecture and hormonal axes.
• Meal timing may affect the gut microbiome: understanding these rhythms could open new avenues for improving feed efficiency and intestinal health in livestock.

There is a discovery that in recent years has swept through medicine and nutritional science, earning a place even in everyday conversation: “when” we eat matters, metabolically, almost as much as “what” we eat. The chronobiology of nutrition has accumulated over two decades an impressive body of research on humans, from intermittent fasting to the synchronisation of meals with light-dark cycles. And yet, if one steps across the door of a barn and asks the same question, that is “at what time does this animal eat, and what happens if that timing is disrupted?”, one finds oneself facing an almost untouched field of research.

From humans to livestock — and back

The transfer of scientific knowledge from human to livestock species has been enormously important and will continue to be so for this sector. But is necessary to underline that is not a one-way street, for example the techniques of oestrus synchronisation and embryo transfer, developed in cattle to meet the demands of genetic improvement, provided the conceptual model from which human reproductive medicine was born, a genealogy that clinical practice tends to forget, but that animal scientists know well.

Returning to the field of nutrition and chronobiology, pigs, cattle and poultry share with humans the same circadian architecture and the same hormonal axes. An animal housed in a shed with constant artificial lighting and continuous access to feed lives in a state of potential chronic desynchronisation between its biological clock and its environmental signals. The unexplained variability in performance among genetically homogeneous animals fed the same diet may be concealing a chronobiological component that has been systematically overlooked. This line of research seeks to uncover the effects of microbiome chronobiology.

The microbiome and meal timing

Recent studies in humans show that intestinal bacterial communities oscillate rhythmically over the course of twenty-four hours, altering their composition and metabolic activity in synchrony with meal timing. Disrupting that synchrony, as occurs in shift workers, impoverishes microbial diversity and compromises immune and digestive function.

In animal husbandry, where the gut microbiome is recognised as a crucial determinant of feed efficiency and intestinal health, no one has yet asked whether nocturnal or continuous feeding protocols may be unintentionally destabilising the very ecosystem that costly probiotics and prebiotics are meant to optimise. It is a straightforward question that deserves an answer. Only in recent years have studies begun to emerge with promising results. We will be hearing much more about this.

Source: Newsletter EAAP n.295