What to consider when planning a compact calving system

A key aim for any beef farmer is to produce a live calf from every cow each year. Compact calving periods are therefore vital for a productive and profitable herd.

Helen Rogers, a vet and director at Friars Moor Vets, says that before farms start shortening their breeding period there are important planning stages to undertake.

One major requirement for removing the bull is a safe pen or field to keep it in.

It is also important to be strict and make a note on the calendar reminding you of the required bulling period.

See also: 9 tips on buying a bull and getting him off to a good start

Step 1

Identify and remove problems

  • Aim for a 12-week (four cycles) block for cows and a six-week (two cycles) block for heifers. You can always shorten your cow block to nine weeks (three cycles) later and if you sell/finish heifers that don’t get in-calf in six weeks you will ensure a fertile herd going forward.
  • Cull cows recorded as calving outside the target period last year. Culling 5-10% is normal.
  • If late-calved cows are in-calf, consider selling them in-calf or with calves at foot and retain more replacement heifers if necessary.
  • Check you have enough maiden heifers to replace your late calvers. Consider using AI and female sexed semen to boost numbers.
  • The target is to calve 65%-plus of cows in the first three weeks and 95% by the end of the second cycle.
  • For those with spring and autumn blocks, manage these as two separate entities, rather than moving cows with poorer fertility between blocks.

Step 2

Body condition score and nutrition

Forage should be analysed to aid ration design and maintain optimal body condition of cows and bulls throughout the year. Silage D-value affects the supplementary concentrates required to stop cows losing condition.

Condition scores should ideally follow the following trends:

Spring calving: Weaning 3.0; calving 2.0+; mating 2.5

Autumn calvers: Calving 3.0; mating 2.5; turnout 2.5+; weaning 2.5

Tasks for maintaining condition





  • Ration cows for winter and group according to which cows need to gain/lose condition
  • Group cows based on their condition score and feed accordingly
  • Consider housing first lactation animals with thin cows


  • Make sure spring calvers are going to calve at the right BCS and gauge what to feed autumn calvers after mating
  • Cows can be regrouped and rations altered


  • BCS spring calvers to maximise fertility and avoid overthin/fat cows. Autumn calvers can be moved to grass according to body condition
  • Best pastures can be used to add condition to the leanest cows
  • Autumn calvers could be weaned early if they are in poor condition
  • High quality grass offers an energy boost and can bring animals back into heat faster


  • Assessing weaning condition helps achieve target condition score at calving
  • Group cows on condition
  • Offer priority grazing/feed for thin cows. Very fat cows should have grazing tightened up, be weaned later or be housed and fed a diet higher in straw

Step 3

 Disease control and health plans

  • Make sure infectious diseases are under control with herd testing and discussion of results with your vet.
  • Meet trace element needs, as these can be related to early embryonic death and poor calf health.
  • Blood sampling can identify deficiencies. This should be done two months prior to calving.

Step 4

Bull management

  • With less time to breed, it’s vital that your bull is working well and that you act if he isn’t.
  • Early pregnancy diagnosis four to six weeks after bull turnout can identify if a bull has not been working. Later pregnancy diagnosis allows empty cows to be sold before housing.
  • Mixing known early and late calved cows can mean the bull’s workload is shared out. If you group all early calvers together, make sure you have enough bull power available (target one bull for 30-40 cows).

Bull condition

  • Bulls should have locomotion, testicles, sperm and penis assessed and be at a BCS of 3.0 when they are given a pre-breeding examination ten weeks before breeding. A vet can do this for about £87-£140 (ex VAT) depending on numbers tested.
  • Quarantine bought-in bulls for four weeks and acclimatise them for a further four weeks as it takes 60 days for semen production to take place.
  • Exercise is important for bulls. Simple measures such as placing feed at the opposite end of the field to the water trough can achieve this.

Bulling time

  • Give bulls extra attention. Ensure they are serving cows effectively. Record cow numbers and heat dates and if multiple animals are in heat three weeks later, there could be a problem with the bull.
  • Don’t overwork a young bull. Mature bull-to-cow ratios are often advisable at 30-40 cows per bull. Young bulls may serve only 20-25.
  • Rotate bulls if possible or undertake pregnancy diagnosis early so infertile/sub-fertile sires can be identified.

Step 5

Breeding methods

  • Shortening your breeding period may present an opportunity to benefit from synchronisation and artificial insemination (AI) to increase the number of calves born in the first three weeks of calving.
  • Good conception results using intravaginal progesterone-device synchronisation regimes in maiden heifers are typically 60-70%, and 100% conception is possible.
  • Maiden heifers must be at target bulling weight and should have a reproductive tract score (to identify if ovaries are cycling) and pelvic area assessed before being selected as a candidate for synchronisation.

Costs of breeding methods compared


Approximate cost


Natural service

£55 a calf born (30 calves) or £33 a calf born (50 calves)

Based on a bull purchase cost of £4,000, a cull value of £1,200 and an annual cost of £700 a year for four years. Winter feeding and bedding costs at £360, summer grazing at £100 and fixed costs of £500, giving total costs of £1,600/year

AI and synchronisation

£85-£115 a calf

Synchronisation drugs will cost about £35 a cow (ex VAT), vet time to inject/inseminate cattle £40-60 a cow and semen £10-£20/straw (dependent on your handling facilities and throughput)

Teaser bull

Procedure costs approximately £100 (ex VAT and drugs) or an epididymectomy achieves the same goal for about £80 (ex VAT and drugs)

Additional costs of rearing, grazing and vaccinating the teaser should be considered

Heat detection technologies

Variable. Includes farmer times observing heats, tail paint and more expensive and sophisticated technology.

Defra’s latest farm productivity grant offered £3,825 for base units (transmitter/receiver/software) and £98 for foot/collar tags

Benefits of compact calving

  • Labour Less time supervising calvings. Fewer late calvers means calf size is controlled, minimising dystocia. Calves are more uniform and easily managed.
  • Feeding Optimising cow BCS is easier as their dietary requirements and lactation/gestation stages are more alike.
  • Health: Longer calving periods offer pathogens more time to build up in sheds and older calves to pass disease on to younger, more susceptible animals.
  • Herd fertility Heifers born earlier in the calving period have more time for growth to reach target bulling weight (60% of mature cow size) by 15 months to calve at two years old. Reaching puberty earlier means heifers can have cycled multiple times prior to the start of breeding, increasing conception rates.
  • Calf value Higher average weaning weights and less weaning checks in bigger calves.