Drought: early weaning may be an option

Drought: early weaning may be an option

Friday, December 15, 2017


Well-grown fawns and their mums in mid-February. Photo: Jamie Ward

KEY POINTS

  • Early weaning can be the best thing for fawn growth under drought conditions or when ryegrass/clover pastures have dried off in late summer.
  • Early weaning can also be the best thing for hinds that have lost condition during lactation. It enables them to recover condition rapidly in time for mating.
  • Early weaning is considered to be when fawns are around 75-80 days old, rather than the traditional 90-plus days.
  • Early-wean only if there is enough high-quality supplementary feed and/or forages for your weaners, but not enough for the hinds.
  • Fawns need time to adjust to dietary changes. While they are still on their mums they need to have been introduced to, and have adapted to, the feed they will be eating after weaning.
  • A reasonably good feed source is needed for the hinds to enable them to recover condition.
  • Consider delaying tagging, vaccinations and drenching until fawns are older (to reduce stress).

MAKING A CALL

At a pre-Christmas meeting, farmers in the Mid-Canterbury Advance Party agreed it was very dry and action was needed.

It was agreed that there was emerging competition for high-quality feed between lactating hinds and their fawns, and for fawns after weaning.

‘Levers to pull’ to protect next year’s production were discussed and the idea of early weaning of fawns came up for discussion. Other options across the whole farm system included weaning lambs earlier, selling store lambs or trading cattle or purchasing fewer trading lambs.

The potential and proven benefits of early weaning are:

  • Quality feed is targeted at the stock class that requires it the most and produces the most $ return/kg DM eaten i.e. weaners.
  • Lower hind energy demand. Because hinds are no longer lactating, they use 100% of their feed intake for maintenance and putting condition back on. They are capable of doing this very rapidly.
  • Feed demand by hinds is reduced by 12-20%.

First consider all the implications

  • Draw up a drought plan early. This provides you with options and flexibility. Having a time-line of dates (e.g. if no rain by 25th December) allows you to react promptly and take control.
  • Proactive planning can mitigate the impacts of a dry season, both for this year’s crop of fawns and next season’s reproductive success.
  • Consider early weaning. This may be best suited to extensive farms where supplementary feeding of hinds with fawns at foot is challenging.   
  • If you decide to early wean, set the farm up for it well in advance.
  • If you are breeding weaners for sale and want to early wean, have a chat with potential purchasers about how soon they can take your weaners.
  • If your purchaser expects to feed supplements to the weaners, make sure you will be both feeding the same supplement.
  • Expect a death rate of less than 1%.

How early can weaning be done?

  • Before 75 days is too early, as about two-thirds of a fawn’s diet is still milk.
  • At 75-85 days, well-grown fawns can be weaned, but be cautious.  If you haven’t weaned this early before, start at 80 days. Your weaning and feeding practices need to be top-notch (see below).
  • Ideally, hinds will be running in mobs based on their fawning dates determined by foetal aging scans last winter. This gives you greater confidence about when you can safely wean.
  • If there is a wide spread of fawning dates in a mob, greater caution is needed. But as a rule of thumb, on typical farms, well-grown fawns born on the first cycle can be weaned from mid-February if they have access to quality feed which they are already familiar with.  
  • Early weaning only part of a mob will compromise any un-weaned fawns remaining in the mob. The whole point of the exercise is to lower hind feed requirements and to give the fawns priority access to quality feed.
  • First-fawning hinds typically have fawning dates 10 days later than mixed aged hinds, so need to be weaned later, as should second or third cycle fawns from mixed aged hinds.

What do I need to think about health-wise?

  • Plan your health programme in advance with your vet. This can form a part of a wider deer health review.
  • Minimise stress on the fawns (see below).
  • Review the timing of vaccinations in the light of an earlier weaning date.
  • Yersinia:
    • Minimising stress is key
    • Yersiniavax™ label recommendation is to not start the programme in fawns less than 120 days old.

What do I need to think about nutrition-wise?

Weaner nutrition should be geared around feed consistency and gradual change. Ideally they should be fed pastures that have plantain, chicory or clover providing up to 11.5 -13 MJME/kgDM. In a drought this is unlikely, so aim for at least 10.5 MJME/kgDM (using supplements as required) and pasture covers of at least 10 cm.

Snap-dried feed like clover can still be high energy.

Monitor hind condition. In a drought or in late summer on dry hill country pastures, the body condition scores of lactating hinds can easily drop to 2-5 to 2 or slightly less by mid-February. If this occurs you are probably better off weaning.

Following weaning, make sure feed quantity and quality is sufficient for hinds to recover condition. Target body condition scores should be at least 3 to ensure good conception rates when they go to the stag at around 10 March.

Nutrition summary:

  • Young fawns’ rumens are still developing.
  • Their rumen bug population will be geared to what they are eating while with mum.
  • Before weaning, to reduce nutritional stress, familiarise fawns with at least one feed element that they will eating after weaning (grain, silage, grass). Rumen bugs can take three weeks to adjust fully to a new feed.
  • Some farmers use rumen health products such as pro-biotics and supplement with vitamin B12 to support rumen health through transition periods.
  • If fawns have come off hill blocks where the diet has been largely tussock/brown top or simply low-quality feed, keep them on grass.  If grass volumes are short consider supplementing them with quality hay or baleage. After the first week or two gradually transition them onto improved pastures, specialist crops such as summer rape or lucerne, or concentrates.
  • For more information see the Deer Fact: Drought feeding and management

Minimise stress at weaning

  • The Aitken method can greatly reduce weaning stress. This involves returning the newly weaned fawns back to the paddock where they had been with their mum for a few days before weaning. They settle very quickly so long as the hinds are relocated as far away as practicable. 
  • Where possible, make weaning a single event – especially if weaning early. It will depend on the farm, but consider delaying tagging and health management jobs for a later date, once fawns have settled. This is particularly important on farms where the fawns have not had much previous exposure to human activity (such as supplementary feeding).
  • Consider running dry or surrogate mothers with the fawns after weaning, at a ratio of four to 100 weaners.
  • For more information see the Deer Fact Best practice weaning management and the Hind and weaner feeding app: www.deerfeed.co.nz

This fact sheet was prepared for DINZ by Lorna Humm, with input from Tony Pearse and Jason Archer. While due care has been taken, DINZ cannot take responsibility for decisions based on the content. If in doubt, please seek professional advice.