The common negative comments about triplets are that they often rear fewer lambs than twinning ewes, have a high ewe death rate, or that they wean tiny, worthless lambs. Many farmers have tried to manage triplets on their own and had a poor result, so have returned to not giving them special treatment.
In many flocks the presence of triplets, but not recorded, accounts for what seems like good lamb survival. To not manage tripleting ewes differently from the rest of the flock in most cases is inviting a lost opportunity. It could be inviting a poor result which, in some cases, could verge on being an animal welfare issue.
Tripleting ewes are an inevitable consequence of high pregnancy scannings. The multiple ratios are well-established in nature and are resistant to manipulation. From time to time a breeder will claim to have defied nature, but the reality remains that most of the extra lambs being carried as triplets will lift exponentially from 170% on.
It is not surprising that ewes carrying triplets have higher energy demands than other ewes. This applies before and after lambing. The energy demand from three nearly full-term lambs is about 10% higher than a ewe carrying twins. The challenge for late pregnant ewes is being able to consume enough, and this particularly applies to tripleting ewes. While they cannot really consume more than twins, they cannot tolerate not being fed enough.
Although the same applies to twins, those ewes are more able to buffer feed shortfalls. It is the shortfall of energy intake to match the demand that forces the ewe to use body fat as an energy source. The by-products of this process are toxic and firstly lower lamb viability, then when that shortfall is greater, threaten ewe viability. So the outcome often seen with tripleting ewes is dead lambs and less often, but more so than other ewes, dead ewes.
It is not just that energy shortfall that is a challenge for ewes with triplets. These ewes carrying three lambs into late pregnancy are metabolically delicate. For MA ewes at least their ability to maintain a balanced macro element status is much compromised. That means they are susceptible to metabolic diseases. Mostly magnesium and calcium get out of kilter, causing just the same outcomes as seen with underfeeding. A common cause of this outcome, though, is that these delicate animals are grazed on high-risk pastures as they come into lambing. These are chosen because they are high quality and high covers. Yet we would never calve a mature, Jersey cow in good condition on that pasture because of the risk of her falling over. A triplet ewe has the same risk.
Tripleting ewes are an inevitable consequence of high pregnancy scannings.
This is often a case of being killed with kindness with these ewes and is frequently the cause of a bad outcome when the effort has been made to look after these ewes. The great triplet lamb and ewe survival seen when lambed on herbs such as plantain is due to not just being well fed but being on a balanced diet.
The other feature of ewes with triplets in them is that they cannot tolerate being in light condition. As for the underfeeding, twinning ewes perform best when lambing in condition score three, but many manage being below that. Tripleting ewes cannot, and must be rescued at scanning, because even if they are fed appropriately, being light limits their ability to cope.
There are many reported successful systems to manage triplets ranging from full-on intervention to supplementary feeding to lambing on hills. The economics of the intervention one is so dependent on the lamb price and female shepherd availability. The same applies to supplementing. This has to be approached carefully to avoid still underfeeding and needs to be started early.
Lambing tripleting ewes on gentle hills where they have room can meet lots of the requirements to get a good outcome. With the room there is diet choice, so there is enough feed and it is more balanced than newer pasture swards on flats. As well there are more lambing sites on hills.
Because three lambs have a greater milk demand than two lambs do, maximising the triplet ewe lactation is vital to getting good lambs at weaning. Getting the package right for going into lambing acts as a buffer for what can be offered after lambing. Ideally, though, these ewes need to be on 1200kg/DM/ha covers or more in early lactation. A lactating triplet ewe has a 40% higher demand than a twin ewe, so must be allocated more. Triplet lambs, if one of three, will eat more pasture than their twin mates. Therefore just as important as giving the ewes enough feed is for the lambs to have access to quality feed. The extra ordinary lamb weight gains of triplet ewes on herbs are largely due to the quality of feed that the lambs can consume.
Often managing tripleting ewes is not profitable because too much resource is allocated for too little return. A good outcome does result from good condition ewes on adequate feed that is well-balanced. The cost of doing that will vary from farm to farm, but knowing that weaning 220% or more, consistently, is achievable should be the spur to make any system profitable.
- Trevor Cook, veterinarian, Manawatu.
