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Feed is a key consideration in development and well-being of young calves, therefore the quality of feed needs to match your desired outcomes.

The younger a calf is, the closer it’s diet should be to whole milk. Once they’re over four weeks old their digestive system has developed enough that they can cope with a wider variety and quality of feeds, but there are growth and performance impacts that can come from feeding poor quality feeds to young calves.


Whole (bovine) milk consists of 3.3-3.5% protein which consists of 2 types of protein – caseins (~80% of the milk protein) and whey (~20% of the milk protein) proteins.  Both casein and whey proteins are being used to produce calf milk replacers. Caseins are large proteins that curd and are what clumps together and solidifies when you make yogurt or acidify milk.

Whey proteins are much smaller and do not curd. The differences in curding behaviour between casein and whey affect the transit rate of milk replacer through the digestive tract and therefore performance of the calf. Scientific research suggests that a curding milk replacer fed to calves less than 14 days old can;

  • Increase growth rates
  • Develop insulating fat around the organs
  • Lower mortality rates in calves facing bacterial infection

(Information source: Beef+Lamb Research and Development, June 2012.)


Skim or whey powders must have fat added back into them to provide high enough levels of fat. Vegetable fats are cheaper than milk fat therefore the likes of palm, coconut, and canola oils are used.

Combinations of these oils can provide reasonably similar profiles to the composition of milk fats, but they aren’t the same, and the same issues around digestibility apply to fats as well as proteins.

Significant fat digestion in the neonate occurs in the abomasum, and some vegetable fats decrease curd formation, hastening passage into the intestine and reducing digestibility.

Milk fat is also the only fat-containing butyrate, which is important for a young calf’s rumen development. In calves under four weeks of age, it is a good idea to limit high quality vegetable fats to no more than 10% of the fat content in their calf milk replacer.

Give tomorrow’s stock the best start in life today

The importance of feeding good quality colostrum

Calves are born with a naive immune system and have no resistance against bacteria and viruses that can cause disease. Colostrum contains very high concentrations of immunoglobulins (defense proteins), and for the first 24 hours or so after birth a calf’s intestine is porous to these antibodies, allowing the calf to absorb them and transfer the immunity of the mother to the calf.

Rehydration during scours

Calves suffering from scours lose fluids and salts and don’t absorb the sugars they need for energy. This can cause alarming weight loss and dehydration. Therefore, lost fluids and salts must be replaced as soon possible to maintain calf energy.

  • A good quality oral electrolyte (such as Novolyte) at therapeutic levels during the diarrhoea and recovery period is the most efficient way to ensure optimum calf health.
  • Oral electrolytes are lower in energy than milk, so milk feeding should be continued during the scouring period.
  • It’s important to feed both milk and electrolytes during rehydration. Ideally feed 2L of milk followed by 2L of electrolytes. These feeds should be 4 hours apart as the electrolytes can interfere with milk digestion.
  • Use high-quality electrolytes such as Novolyte to ensure a balanced intake of salts and energy.
  • Electrolytes can be offered via a teat feeder, trough, bucket or tube feeder.
  • Warm feeding (38°C) is recommended to increase voluntarily drinking.