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Jess' Diary - Serving Heifers

Jess' Diary - Serving Heifers
By Jessica Charlton 2 years ago

Give priority to serving heifers.

Rearing heifers is a costly business, to receive a significant return on investment heifers must calve at 24 months or less, get in calf quickly, calve without difficulty, produce well and get back in calf.

Serving heifers at the right age, frame and body condition is perhaps one of the most important stages of the animal’s life and has a huge impact on future profitability and lifetime performance. Live weight is a much better indicator of when heifers commence oestrus activity (cycling) than age, as heifers that are well grown commence cycling at an earlier age than their lighter herd mates and get in calf quicker. Research shows that heifers that are heavier at first calving have the potential for superior reproductive performance. Heifers should be suitable for breeding at 13 months old and calve at 22-24 months old, calving at this age has been proven to be the most cost effective and profitable time to calve heifers.

To produce well grown heifers suitable for serving at 13 months old the management practices must be in place from day one, this means providing the heifer with:

  • Good quality colostrum within 6 hours of life
  • High quality milk replacer (Wynngold Bloom or Turbo Start)
  • High quality palatable starter (Wynnstay Start N Wean)
  • Step down weaning (minimum of 8 weeks, and be consuming 2kg starter)
  • Appropriate post weaning ration (Straw and Heifer 600 or Rearer 18)

A body condition score of 3 is important in bulling heifers

A heifer should weigh 55% of the herds mature bodyweight at first service, this way the weight is unique to the farm and its genetics. If the average Holstein cow weighs 680kg then the ideal serving weight for that farm would be 374kg, but this will alter depending on breed, for example we serve our cross bred heifers at 320kg. To achieve this, they must grow at an average of 0.8kg/day. Monitoring weights is vital, it allows us to know where the heifers are up to and if they are on target. We weigh heifers every three months, this enables us to closely monitor not only the growth rates but the body condition of the heifers and make any nutritional changes necessary. They should be at a body condition score of 3 at service, and not over fat as this will decrease fertility, lean growth is key.

Syncing heifers

As we are a spring calving unit all of our heifers are synced using a CIDR programme and fixed time AI. As the heifers are reared away from the grazing platform handling to serve cannot be practically done off natural heats. For conventional systems working off natural heats is just as effective, but heat detection is absolutely key and should take priority. We have 4 Angus bulls to 100 heifers and expect a conception rate of 60-65% to first service and anything not caught is got by the bull. Whichever system you use, timing is key. Do not lose too much time with heifers as the age can quickly creep up, especially if there are other jobs to get on with, serving heifers should be a priority.


Heifers are one of the costliest enterprises on the farm and improving performance is key to maximising profits and herd performance.

Jess Charlton

Calf Specialist

Jess joined Wynnstay as a Calf Specialist in January 2017 having previously worked at Walford College teaching Agriculture.  She currently lives on a 400-cow spring calving dairy unit in Shropshire with her partner.

Follow Jess on Twitter @charltoncalf1 or contact the Wynnstay Calf Team.

Posted in: Dairy Farming