An update on the Making maidens’ weight PDS project

Lamb marking results from demonstration flocks

Despite experiencing one of the best seasons in Central West Queensland during the 2023 lambing period, both mobs of Merino maiden ewes in the two demonstration flocks fell short of our target of >90% lambs marked from SIL maidens.

The 2023 lamb marking results from these flocks are consistent with anecdotal comments from many discussion group members. Results to-date show we were able to get our maidens pregnant, but the challenge lies in keeping the foetuses alive to lamb-marking.

This is why this Producer Demonstration Site (PDS) is so important. Can we find ways to improve lamb marking results from our pregnant maiden ewes? The benefits of achieving this will transfer to the mixed age (MA) ewes which will have a significant impact on the bottom line of our businesses.

Results from Dunblane

#Scanning = ewes pregnant as a % of all ewes in yards at scanning

^Fertility rate = number of foetuses per 100 ewes joined

@Lamb marking = lambs marked as a % of ewes in the yard at lamb marking

*Dunblane MA ewes were only scanned for pregnant or empty

Results from Beaconsfield

Results from members of the discussion group

Thank you to everyone who supplied us with results to include, it certainly adds to the understanding of what’s happening on the ground and assists with identifying where this PDS can benefit producers. Some producers have recorded very good scanning and marking results from their maidens.

Background on PDS project

The challenge in Central West Queensland lies in ensuring our maiden ewes raise their lambs. The disappointing lamb marking results raises the question as to what is causing the lamb losses from scanning to lamb marking.

Merino maiden ewes are well known to be less fertile than their older sisters, the MA (Mixed Age) ewe cohort. A commonly held belief is that maiden ewes typically achieve 80% of the lamb marking results of the MA ewes. Nevertheless, work done by researchers in recent years suggest that this gap in performance has closed. 

Possible causes for this year’s poor performance in the demonstration flocks are discussed below: 

Mismothering

Mismothering with the amount of tall grass (up to 1m) meaning it was very easy for lambs to lose their mothers in the long grass at lambing.  If the ewe was disturbed, then there would have been a very good chance that mismothering occurred. This issue of mismothering may have been exacerbated this year because ewes were able to stay in the one spot as a mob due to the feed available. Hence, as each ewe lambed down, particularly with the twinners, that the newborn lamb had no idea of who was the mother, adjacent ewes contributing significantly to the confusion by calling. Many studies of groups of ewes lambing down over a two to five day period in a sheltered yard, or shed situation report similar issues, with significant lamb loss due to mismothering. Lambs simply run out of energy trying to bond with the correct mother.

Body Condition Score (BCS)

Low BCS is well known to affect the ability of the ewe to successfully raise their offspring. In 2023, demonstration ewes were in excellent BCS condition just prior to lambing. Coupled with 4–6 inches of rain, it is unlikely that low BCS was an issue.

Pasture

• Did the quality of the pasture affect ewe nutrition? Tall cup grass (Eriochloa crebra) was abundant in many pastures this season and whilst it is palatable and nutritious to stock, it produces a lot of stalk that becomes rank.
• There were no poisonous plants noted.
• Pasture quantity was not expected to be an issue in 2023. Ewes that either slipped or lost their lamb at parturition were in excellent condition ie BCS of 3+. It is believed quantity of pastures was not an issue. Ewes lambed down in pastures of well in excess than 3,000kg DM/Ha with a wide range of plant varieties allowing ewes to select a high quality diet.

Environmental issues

Weather effects were unlikely as winter has been mild.

Genetic selection

• Beaconsfield reports that their rams are about average for NLW (Net Lamb Weaned) (ASBV).
• Dunblane reports placing very little real selection pressure for fertility through female selection although all self-bred rams have above average scrotal circumferences as a selection criteria.
• Historically, the use of specially selected AI sires including several leading Billandri sires is expected to have had a positive influence on flock fertility and NLW.
• Recent changes to a new ram source are also expected to improve flock fertility although the introduction of these genetics is too new to influence the yellow tag ewes.

Predation

• Few birds/hawks were seen over lambing flocks on both demonstration flocks. No claw marks were found in any lambs at lamb marking on either demonstration flocks.
• Foxes are rare on Dunblane nowadays.
• There was no evidence of dogs in either flock for over four years.
• No pigs were observed on Dunblane and an isolated sighting at Beaconsfield.

Disease

• Scabby mouth – a severe outbreak occurred at Dunblane in the maiden ewe lambs. Beaconsfield had a mild break out of scabby mouth.
• Camplyobacter – Dunblane ewes were not vaccinated, Beaconsfield ewes were.
• Internal parasites – unlikely, the ewe BCS suggests that this was not an issue prior to lambing.
• Fly strike ­– Yes, Dunblane had a major outbreak in the singles, some mismothering would have occurred here when ewes were breech jetted during lambing. Dunblane twinners were treated before lambing. No issue at Beaconsfield 

Discussion

So, what do we do differently next year and can the lamb marking percentages of maidens be improved in western Queensland?

Below are some questions leading into the management of maidens next season and for the winter zoom session:

• Should we question the accuracy of the preg tester?
• Did predators play a significant role?
• Should we lamb down in smaller mobs?
• Should we lamb down in smaller paddocks?
• Is mismothering contributing to lamb mortality?
• To what extent did the outbreak of flystrike impact lamb survivability?
• Should we test for Campylobacter?

Keep up to date with this PDS project

We have recently created a What App text message chat where producers can discuss anything they are seeing in the paddock or in their flock. Please contact David Counsell (0427 073 606) if you’d like to join. The monthly Leading Sheep newsletter will contain semi-regular updates on the PDS, sign up here. You can also give us a follow-on Instagram @mmwmlapds to keep an eye on what our demo flocks are up to.

Upcoming activities

Are this year’s red tag maidens on track?

The Dunblane red tag maidens, due to be joined for the first time on the 1^st Oct 2023, were weighed on the 20^th May 2023. The average weight was over 50kg, with only 5% of the mob less than 42kg, this mob is on track for an excellent joining.   This is reflective of the excellent seasonal conditions occurring over the past summer.

In fact, the question may be asked, should we or do we consider joining these ewes as ewe lambs?

These ewes will be weighed again in the coming weeks.

Figure 1. Dunblane red tag maidens, May 2023

How are the Dunblane blue tag weaners looking

The average weight of a sample of 150 ewe lambs weaned from MA ewes was 19.68kg, of concern, was the large group of weaners under 15kg.  The age of these weaners was 18 weeks at weighing (from the start of lambing).  If not for the rain (55mm) in early July, these weaners would have faced considerable risks over the next 3-6 months until summer rains arrived. At weaning, the Dunblane weaners were vaccinated but not treated for internal parasites or with preventative flystrike treatment.

Figure 2. Dunblane Blue tag maidens at weaning, July 2023

Upcoming Management reminders

The following are reminders of upcoming management and animal husbandry activities.

• Lamb marking
  • All lambs tail docked and earmarked, males castrated.
  • On the demonstration flocks, female lambs tagged with (non-NLIS) EID tags, male lambs tagged with management tag. Question for discussion, do we start tagging all lambs with NLIS EID tags before it is mandatory, so we don’t need to tag them when we sell them?
  • All maiden ewes wet and dried and results recorded against EID and a sample (20%) of maidens were weighed and condition scored. Wet and dry udder assessment is a useful and quick practice that can help pinpoint whether the losses occurred before or after lambing.
  • Question, do we or should we use pain relief at lamb marking? Those producers involved in RWS accreditation programs will be doing so.
• Imprint feed the lamb weaners (feed ewes and weaners for 2-3 weeks prior to weaning). With El Nino predicted for the upcoming summer and winter looking reasonably dry, weaner growth rates are expected to be depressed as weaners graze the poor quality hayed off Mitchell grass pastures. In case some feeding is required, training the weaners onto supplement (whether cereals or grains) early may save time and production losses if the pasture quality continues to decline. After some recent winter rain it is likely that some forbs and herbs will be cropping up in pastures, with lambs tongues, wild carrot and daisy burr providing short term high quality feed for small ruminants.
• Weaning
  • Wean at 14 weeks from date of first lambing.
  • All maiden ewes condition-scored and female weaners weighed, data collected against EIDs.

• Red taggers on target
  • Weigh red tag maidens regularly to ensure you are on track for a successful joining in late spring.
  • Have in place a strategy to help lighter red tag ewes gain weight to ensure they hit weights targets to have a high chance of falling pregnant during the joining period.

Welcome new members

Anyone wanting to examine the fertility of maiden ewes is welcome to join this discussion group.

We would love more demonstration flocks to be involved. If you are interested in providing data to support this project and come along for the learning journey through discussions specifically relating to your operation, then this is a great opportunity. Please contact one of the organizing committee members if you are interested.

All small ruminant producers whether that be goat, meat sheep or wool sheep producers are welcome. You can expect the benefit of trialing similar strategies to improve your flock management and production in a highly supportive group.

Image 1. One of the demonstration flocks, Dunblane, purchased an auto-drafter to assist with processing animals efficiently through the yards.

Image 2. Imprint feeding of merino weaners at Dunblane, early June 2023. Image supplied by David Counsell.