Triplets don't always have to be trouble
By Monica Ley
Senior Land Services Officer
Mixed Farming Systems
- Employ an accurate and reliable scanner who can identify multiples.
- Managing your mobs in relation to number of foetuses and feeding accordingly will improve ewe condition. Reducing mob size can improve lamb survival.
- Ewes bearing triplets require extra attention and management compared with both single and twin-bearing ewes including more nutrient dense quality feeds.
There has always been a bit of a rivalry between Australia and New Zealand, particularly on the sporting field, but I’m afraid the management of triplet ewes and lambs is where they have us beaten. While the majority of research, trials and management strategies on managing multiples come from over the ditch, a lot can be applied and adapted to the Australian flock. Additionally, with the current high prices for sheep and wool, managing the ewes that are able to wean more lambs in a lifetime than their flock mates would boost the overall productive efficiency of your enterprise.
Triplet-bearing ewes are our most productive animals and have the ability to wean more kilograms of lambs per season, so it makes sense to look after them. Having three lambs and a ewe to look after doesn’t always have to be a hard task if you plan and manage them accordingly both during pregnancy, lambing and lactation.
We are currently seeing an increase in the number of flocks achieving scanning rates of over 200 per cent. This growth in litter size can be attributed to the decline in single-bearing ewes and is offset by an increase in triplet-bearing ewes. One significant differences is that, unlike the Australian sheep industry, New Zealand sheep producers have extensively adopted pregnancy scanning, with the majority scanning for not only multiples, but determining between twins and triplets. This has been made possible through a self-regulating scanning industry.
To best manage triplet-bearing ewes and their lambs, we must firstly know which ewes they are and how many are within the flock. Pregnancy scanning is a great yet largely under-utilised management tool that assists producers to improve profits across meat and wool enterprises, particularly farms with higher stocking rates or with a low supply of paddock feed. While benefits vary with the season, the reproductive rate of a flock and the management of the scanned ewes have the ability to affect the overall flock structure. During tough seasons, maintaining optimal production and identifying weaknesses such as repeat dry ewes allows for them to be identified early and sold off without using feed that could have been better allocated to single, twin and especially triplet-bearing ewes.
The decision to pregnancy scan ewes, either for wet/dry or multiples, depends on the goals of a farm business, and this decision is also usually derived from what is planned to be done with the information. If producers are scanning for multiples, though not managing their flocks according to pregnancy status, the benefits of scanning significantly drop.
Finding and employing a pregnancy scanner who is not only accurate in determining wet/dry, but is also relatively confident in determining multiples and early and late lambing can be essential in a difficult season. This is because the value of scanning increases within droughts or when there is likely to be low feed availability over pregnancy.
While single-bearing ewes are able to lamb in larger mobs, twins and triplets need a much lower density stocking rate to increase their survival. This is due to the fact that not only are smaller mobs of multiple-bearing ewes are easier to manage, but they also have a higher instance of mismothering due to other ewes wandering through the birth-site and adopting the first born lamb of another ewe. Reducing the mob size of ewes carrying multiple foetuses allows them to be able to find their own space to give birth, which can ultimately lead to higher lamb survival.
There has been much debate about the optimum number of pregnant ewes within a mob, though studies indicate that twin-bearing ewes have greater lamb survival rates in mobs of 75-150, with triplets lambing in much smaller mobs of 30-50. Despite single bearing ewes have an overall higher lamb survival rate, survival does decrease as mob sizes increase over 300 head.
While mob size is advised to be smaller to allow for minimal disturbance of the birth site, having fewer ewes per paddock also increases the available feed for dams carrying multiples.
Nutrition and condition
As triplet ewes are growing three foetuses, they require higher quality nutrient-dense feeds compared with single-bearing ewes. While both the membranes and lambs develop and grow in the second and third trimesters, the space available for the rumen is impacted on. During pregnancy with multiples, the volume of the rumen can compress to less than one third of the size of a dry ewe. Due to the reduced stomach space, a triplet-bearing ewe can only consume minimal food and must be able to best use the food that she can eat.
It is vital to ensure that there is the most nutrient-dense feed available to triplet mums, including pellets and concentrates.
Such feeding is not only necessary during pregnancy, but also throughout the lactation period. The body temperature and weight of triplet lambs is generally lower at birth so they require more milk more often than single-born lambs.
Some producers have found benefit in either artificially rearing triplet lambs or grafting the third lamb onto another animal to reduce the overall impact on the ewe. This should ideally be done shortly after birth to ensure that lambs are receiving adequate nutrition for survival and have more chance of being successfully adopted by their new mother.