News & Advice

Young stock grazers – management for best growth

Jun 2, 2022 | Dairy, Grazing youngstock, Young Stock

Erin Fisher, Veterinarian, Anexa Vets Maramarua

Now that the new batch of dairy grazers have arrived on farm it is time to plan how to optimise their growth to give them the best chance of getting in calf.

When yearlings first arrive on farm they should be weighed, and quarantine drenched. Weighing provides an objective measure of where they are sitting in relation to their target weight. Heifers need to reach 50% of their mature live weight by 12 months of age to trigger puberty prior to mating. This will also have a huge impact on the quality of animal that will leave your farm in a years time as well as the number that will get pregnant early.

Recording weights on MINDA has the advantage that it identifies the animals’ genetic potential for mature bodyweight so the animals target weight can be calculated at any given time.

This year there has been significant facial eczema challenge in some areas, so some of the young stock arriving on farm may have taken a growth check if they have been challenged by this disease. They will need extra support in the way of extra feed and trace elements. 

Important questions to ask the owner before they arrive on farm are: 

  1. When were they last drenched and what product? 
  2. Are their vaccinations up to date? 
  3. Is there a mineral plan in place (copper, selenium, etc)?


Key management areas to ensure good growth rates in your grazers are:

  • Predicting the dry matter intake of dairy heifers is an important part of a heifer rearing program, as maintaining target growth rates over time requires increasing the amount of feed offered to meet the increasing demand. Both maintenance and growth requirements increase as they grow. 
  • If the farm is growing enough good quality grass to meet dry matter requirements, then the heifers should be able to reach their growth rate targets. Often the farm becomes short on grass or the pasture is of poor quality and supplementary feed will be required. Grass silage is often poor quality so a better option for growing heifers may be PKE. Increasing feed intakes will not always make up for low quality feed (low MJME/ kgDM). Just because heifers may not be complaining and are full, does not mean they are growing at target growth rates.
  • Regular weighing is the best way to measure heifer growth and help make decisions on adjusting feed requirements if needed.


Trace Minerals
  • A trace mineral plan is important to ensure the heifers are getting enough copper, selenium and B12 (cobalt) etc. These can be given via injections, boluses, prills (fertiliser), and salt licks, depending on how deficient the stock are, how easy/hard it is to yard and handle the stock, the age of the stock, and cost.
  • A mineral plan will be specific to the farm and the heifers grazing on the farm.
  • Lacking in essential trace minerals has a negative effect on growth rates, fertility and their immunity, which can also make them more susceptible to disease (eg. Yersinia and pneumonia). 


Parasite Control
  • For farms that regularly graze young stock, it is important to have a comprehensive drench plan in place ensuring regular treatments with the right products, otherwise pasture worm challenge can be very high.
  • The yearlings arriving for grazing in May should be 180-220kg and at this stage it can be physically difficult to give them an oral drench, so often farmers will reach for a pour-on drench.
  • Drenches should always be a combination product with at least two active ingredients. These will be more effective than single actives and will slow the development of drench resistance on your farm.
  • An effective drenching program will save money and help achieve better young stock weights. Talk to your vet about what is best suited to you and your farm.

Anexa Vets can help you develop a plan for your young stock, with trace mineral plans, drench advice, target weights and assistance with weighing of animals.

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