Why is lactose so important in calf nutrition?

Lactose is a disaccharide (sugar). Lactose is only present in milk and is composed of glucose and galactose. Mammals feed their offspring milk and young animals have the capability to digest milk directly after birth. On the other hand, newborn animals are not able to digest larger sugar chains (polysaccharides) such as starch. This is mainly due to a lack of digestive enzymes.

The digestion of lactose in calves

Calves have the capability to digest milk directly after birth, thanks to the enzyme lactase which is present in the small intestine. Lactose is hydrolyzed into the sugars glucose and galactose Lactase activity is high in milk-fed calves.

Glucose is preferably taken up in the small intestine. Galactose can be metabolized to glucose in the liver and then slowly released to the blood as an energy source. Thus, lactose provides energy to young animals.

The absorption of calcium

Besides energy, lactose enhances the intestinal absorption of calcium.

Calcium is an important mineral in body tissue and, when deficient, it results in reduced growth and development of the calf. Calcium absorption is enhanced by a lower pH. This is achieved by acid forming bacteria that can grow on lactose.

Lactose is also known to induce the growth of beneficial intestinal microflora, thus limiting the colonization of potential pathogenic flora such as E. coli, Clostridium or Salmonella.

In summary, lactose:

  • Is a sugar (disaccharide) only present in milk
  • Is a pure, natural and unrefined nutrient
  • Is hydrolyzed into galactose, which has a proven importance in maintaining nutritional balance
  • Is an important source of dietary energy
  • Is the only highly digestible carbohydrate source for newborn calves thanks to the enzyme lactase
  • Enhances the intestinal absorption of calcium
  • Is used as a readily available substrate for beneficial bacteria