Nutrition in the pre-weaning period needs to achieve adequate growth rates while balancing milk intake against rumen development to get the calf weaned successfully.

Historically, it was recommended to feed milk at 8%-10% body weight as milk each day, but there are several reasons why feeding at the higher range of 13%-15% of the calf’s body weight each day is now considered optimum. For a 40kg calf, that equates to 6l/day (containing 750g of milk replacer) divided into two equal feeds for at least the first four weeks of life:

  • If all calves are fed the same amount of milk, then heavier calves may not get enough to even maintain their weight and lighter calves will be too full and be slower to consume concentrates.
  • Heifers that grow faster before weaning calve earlier and have higher milk producing potential.
  • This higher level of feeding also provides a buffer for when dietary energy demands are higher, such as in cold weather. For example, at 0°C, calves need about 50% more energy just for maintenance and keeping warm.

    • The colostrum 1,2,3 rule is best practice for the newborn calf, followed by transition milk (milk from milkings two to six) for up to three more days on farms where there are no underlying cow health issues, such as Johnes’ disease.

    After the initial first four days, calves should be offered whole milk or good-quality milk replacer. Whole milk, no waste milk, milk with antibiotic residue or high SCC milk shouldn’t be fed.

    When choosing a milk replacer, select a good-quality concentrated whey protein or skim milk replacer. The only legal requirement for declaration on the milk replacer label is that ingredients have to be listed in descending order of inclusion, so the purchaser can only get a rough idea of the quality of the milk replacer from the oil, protein, fibre and ash content.

    Higher quality ingredients are generally more expensive and good performance cannot be expected from milk replacers containing lower quality ingredients.

    In summary, the following specifications are a useful guide:

  • Protein content: 23%-26% (predominantly dairy protein sources).
  • Fat content: 16%-20%.
  • Ash content: 7%-8%.
  • Fibre content: Maximum of 0.1%. (a high fibre content suggests use of plant proteins).

    • The above information is only a very limited guide for a basic assessment of a milk replacer and is not meant to replace the advice of a nutritionist.

    Practical considerations:

  • Start feeding milk replacer once the calf has received adequate colostrum and transition milk (generally at three to four days old).
  • Reconstitute milk replacer at a concentration of 125g/l of mixed milk by adding 125g of powder to 875ml of water to give one litre of mixed milk at 12.5% milk solids. Use scales to measure the powder correctly and ensure consistency. Feed calves milk that is at body temperature (37-39°C).
  • Maintain a high standard of cleanliness throughout the preparation and feeding process.
  • Consider milk replacer as a feed, meaning ad-lib clean water is essential from day three for proper rumen development and solid feed intake.

    • Inadequate nutritional intake (or any other stressor) has a negative effect on the immune system of the calf and leads to a greater risk of developing pneumonia and other diseases like calf scour.

    How to recognise a calf with pneumonia

    Initial signs of pneumonia may be non-specific, such as:

  • Being ‘off-form’.
  • Dullness.
  • Reduced feed intake.
  • Hollow sides.
  • Fever (over 39.5°C).

    • Other signs may include increased respiratory rate, coughing, watery discharge from the nose and eyes. Advanced signs include pus-like nasal discharge and severe respiratory distress.

    Careful observation of calves when they are resting is required, as these signs may not be as obvious when the calf is feeding. If you suspect calf pneumonia, consult your veterinary practitioner as an early diagnosis is essential for a successful outcome.

    How to recognise a calf with scour?

    An intestine that is not functioning properly causes the calf to lose salts and water in the form of diarrhoea, or custard-like faeces, usually a yellow/brown colour, but some can be black or have a red tinge if blood is involved. The initial damage to the gut is caused by bugs (parasites, viruses and bacteria). Clinical signs include:

  • A dirty tail.
  • Hunched back.
  • Calf separated from rest of group.
  • Dull and depressed (head down).
  • Hollow abdomen.
  • Increased temperature.
  • Reduced appetite.

    • As with pneumonia, early diagnosis will have a better outcome. Continue to feed scouring calves normal amounts of milk or milk replacer as long as they will drink, but do not stomach tube.

    All scouring calves need an additional 4l per day of a good-quality oral rehydration solution to replace lost fluids. These should be given in addition to, and separate from, the milk feeds (for example, at lunchtime and again late in the evening).

    It is safe to give these fluids by stomach tube if the calf is not drinking, assuming you are competent and confident with the technique. In the event of an outbreak, or if the calves aren’t responding to treatment, you should contact your veterinary surgeon.

    Animal health tips for January

  • Stock up on supplies for calving season:

    • –Disposable plastic gloves (long and short).

    –Gel and paper towels.

    –Calving ropes (minimum two pairs).

    –Calving jack.

    –Calcium bottles or boluses and magnesium.

    –Disinfectant for navel.

    –Easily accessible clean water.

    –Two 3l bottle with a teats (a separate one for feeding sick calves).

    –Stomach tube (without cracks).

    –Calf tags, notebook or phone app set up to record the calving information.

    –Calf jackets or infra-red lamp for cold weather.

  • Ensure sheds are clean and that straw is easily accessible.
  • Colostrum (fresh or frozen supply from a reliable source) and brix refractometer to test.
  • Make sure your milking machine has been serviced in last 12 months.
  • Develop a Herd Health Plan for 2023.
  • Monitor cows and heifers close to calving for mastitis as they are at higher risk of picking up infection at this time.