Achieving a high percentage of lambs “off mum” takes top genetics and good management, as Gore-based farm consultant Graham Butcher reports.

Sheep farmers like to talk about scanning and lambing percentages, and those that achieve good numbers of lambs weaned off mum often add that one to their repertoire. And for good reason. There is a large range in the percentage of lambs killed off mum and it’s not all related to the farm, stage of development, altitude, aspect, etc.

Much of it is related to genetics and management. Most farmers know what the important factors are but not all farmers achieve good drafts. The difference is probably all about execution. Doing the right things at the right time to make sure it all comes together when lambs hit the ground.

If, for whatever reason, you just can’t get good drafts, the factors in play are still important because they will add to your weaning weights, and that’s good business as well.

You will have seen the AgriHQ graphs in the papers showing average per kg lamb pricing – a five-year average and the last two years – one each for the North and South Islands. A recent South Island graph showed that between late December and early March the average premium available per 18kg lamb was $14 over the past five years. Two years ago it was $17 and last year a massive $25. So, early premiums are very significant.

Another factor is feed savings. We all know that any animal growing fast takes less feed to achieve a given weight. It works that way because the first port of call for a mouthful of grass or milk is to maintain the animal. Once that’s done, the rest of the mouthful goes to growth. If we are underfeeding there’s not much left for growth, most of the feed intake goes to maintenance. So it takes longer and more maintenance feed.

If you take a 28kg lamb at weaning and grow it at about 150g/day it will take an additional 140kg DM to get to a good killable weight. Over 500 lambs, that’s about 300 bales of balage or 6.5ha swedes to put that into perspective. Again, good business to grow very fast.

Then we can look at lower costs for early killed lambs, less work and you get paid for lambs that might have died post weaning. Think about what you could do with the feed saved, the 300 bales from 500 lambs off at weaning. Perhaps provide more feed to lambed hoggets.

To me, if you talk about the scanned percent you are talking about ewe management from weaning to scanning. If you talk about lambing percent you are talking about management to tailing. But, if you talk about percent lambs off mum, you are talking about the whole year’s management.

At a recent Beef+Lamb conference in Gore I led a discussion with two top Southland farmers that achieved outstanding percents off mum who outlined what they were doing.

Ryan Shaw operates 330 hectares rolling to steep country near Ohai with a combination of 1250 ewes (168% tailed), 320 in-lamb hoggets, 190 bulls and 350 dairy cows wintered. He’s only been there four years. In 2018, 75% of lambs were killed off mum at 19.1kg. Remarkable! In 2019, 85% at 18.5kg was achieved. Average lamb price for 2018 was $141 and for 2019, $152. Works lambs are above 36kg and full weaning takes place mid January. Skim drafting is done.

Ryan discussed the key points that help him achieve this.

  • Maximum use of terminal rams.
  • Ewe and lamb rotations, fully fed.
  • Tetraploid grasses for early spring growth, late flowering.
  • Good ewe condition (CS 4).
  • Having a mix of cattle (fewer worms).
  • Drafting from about day 75.

I would add another point: Ryan’s aim is for a Poll Dorset x Texel ewe, with rams of that cross bought.

Lactation ability is critical, and feeding so that ability can be expressed is also critical. The thing about these factors is that we all know about them and it’s not rocket science. It’s all about execution, making a call and then actually putting it in place.

John Lindsay also presented. John runs 1,571ha, including 648ha hill country close to Dipton, with a diverse stock mix of sheep (7500 ewes and 2100 hoggets), breeding cows and deer. All up, about 17,000 stock units.

John runs an interesting breeding policy. There is a base flock of Wairere ewes that are mated to Polled Dorset x Texel rams carrying the Inverdale gene and Loinmax. This provides Inverdale ewe lambs to a flock mated to terminal sires.

The Inverdale flock lambs at 187%, and 84% of lambs are weaned off mum by December 20. Remarkable really.

If we take the Wairere flock into the overall average figures, we get to about 50% off mum at over 18kg.

How does John do it?

He talked about maintaining feed quality by integrating cattle and deer. Pasture grooming needs to start before quality drops off.

Lambing management was also important, with staggered lambing. Flats are intensively shepherded and paddocks split with electric fences into mobs of about 40 ewes. Paddocks are shed off at about 5% left to lamb, and numbers shuffled depending on feed – the “Southland Shuffle”.

Keeping ewe weights as constant as possible and focusing on the bottom end was important. Average weight is not a good measure – you can achieve the target average weight but all that means is that half the flock is underweight.

Triplets are scanned and set stocked two weeks prior to lambing. Twins are added at about three or four days pre-lamb. Stocking rate is about eight ewes/ha, with a 1500kg cover aimed for.

After lambing, cattle are introduced as required, skim drafted every 10 days with a cut-off at 37kg for milk lambs. Balance of weaning is done 20th December.

Pasture renewal critical to this operation.

There are common themes running through Ryan’s and John’s presentations. A very significant one is the genetic makeup of these high performing flocks, with Polled Dorset featuring.

Using a Polled Dorset will increase the size of ewes and probably necessitate removal of wet/dries, but this is a small price to pay.

I believe we underestimate the importance of lactation ability and feed intake for its full expression.

These two farms and farmers show what is possible.

Ryan Shaw lamb production results

  • 2019 season 75% of our lambs off mum at an average weight of 19.1kg
  • 2020 season 85% if our lambs off mum at an average weight of 18.5kg.
  • 2019 average lamb price for the season of $141
  • 2020 average lamb price for the season $152


Single ewe

  • Average birth date: September 2
  • Average birth weight: 5.5kg
  • Days to slaughter: 67 days
  • Live weight: 41.3kg
  • Slaughter weight: 19.84kg
  • Growth rate per day: 534g

Twin ewe

  • Average birth date: September 2
  • Average birth weight: 4.75kg
  • Days to slaughter: 81 days
  • Live weight: 39.4kg
  • Slaughter weight: 18.93kg
  • Growth rate per day: 427g
  • Growth rate per day per ewe: 854g

Triplet ewe

  • Average birth date: September 2
  • Average birth weight: 4kg
  • Days to slaughter: 81 days
  • Live weight: 39.4kg
  • Slaughter weight: 18.93kg
  • Growth rate per day: 437g
  • Growth rate per day per ewe: 1311g