Heifer Rearing

Heifer rearing is a large cost to most dairy farms. To maximise return on the money invested, a system needs to be implemented that ultimately delivers an efficient cow capable of producing to her genetic potential.

Fully growing out heifers by first calving delivers the following advantages.

• Energy is not required for growth during the lactation and can be used more efficiently for milk production.
  
  
• Greater rumen capacity allows them to consume more feed. The resulting higher energy intake can increase milk production and reduce weight loss.
  
  
• Fertility will be better in animals that experience less weight loss resulting in less replacement stock needing to be reared due to better conception rates and less culling of 1^st calvers.Longevity in the herd increases. With less nutritional stress and less bullying from mature cows, heifers are less likely to break down.
  
  
• Udder tissue is still developing in the first lactation. Higher milk yields will increase milk-secreting tissue lifting the production potential for all subsequent lactations.
  
  
• Stocking rate is increased without the cost associated with higher cow numbers, allowing better pasture utilization.
  
  
• Any extra cost incurred to achieve ideal weight can be recovered from higher slaughter value at the end of their productive life.   

There is no one system for rearing calves but the following points are common to most successful systems.

Before birth

By ensuring the cow receives a good transition diet, calving will be easier placing less stress on the newborn calf. Minerals and vitamins in the transition diet enable the cow to supply the calf with sufficient reserves for a strong immune system.

Inoculating cows allows them to pass immunity on to the calf through colostrum.

Colostrum

To achieve immune protection calves must receive sufficient colostrum as soon as possible after birth. Calves should ideally get at least 2 litres within 2 hours of birth and equivalent to 10% of their birth weight within 12 hours.

Milk

Calves should be fed milk at 12% of their birth weight (±5L for Holsteins and ±3.5L for Jerseys) or equivalent milk replacer. Length of milk feeding can vary from 6 to 12 weeks but to achieve optimum growth rates calves should weigh at least 110Kg for Holsteins and 85Kg for Jerseys before they are weaned off milk.

Concentrates

Pellets should be introduced within the first week; although intakes are low the fermentation of carbohydrate is important in starting rumen development. High quality protein is also required for good frame development; calves should be started on a high protein pellet like Barastoc Calf Rearer Pellets, which should be fed until calves reach 140kg. After which Barastoc Heifer Developer Pellets should be fed until the calf can maintain an average growth rate of 0.6kg/day from pasture or forages. Heifer Developer Pellets should be reintroduced if a drop in feed quantity or quality limits growth below 0.6kg between 3 and 9 month or below 1kg between 9 months and calving. These growth rates are required if a heifer is to grow to her optimum size by 2 years old. Exceeding these growth rates is also not desirable as excessive fattening can lead to early puberty, preventing her growing out completely.

Roughage

Straw should be available from a week old. Fibre is important for developing the rumen volume and muscle tone. Straw also dilutes excess protein in the rumen. Once calves are old enough to utilise rumen degradable protein, higher feed value roughage in the form of hay can be introduced.

Even after weaning straw should be available when high protein pasture is being fed.

Water

Water should be made available as soon as dry feed is introduced into the diet.