Mating ewe lambs - an option for your farm?
Damian Costello, Sheep Specialist, Teagasc Animal & Grassland Research & Innovation Programme, Mellows Centre, Athenry, offers key advice in regard to mating ewe lambs.
It’s safe to say that mating ewe lambs to produce their first litter at one year old does not suit every sheep farming system. However, research carried out at Teagasc Athenry indicates that, when managed correctly, maternal breed replacements lambing down at one year old can produce 1.2 more lambs during their lifetime compared to the more traditional system of ewes producing their first lambs as two year olds.
In this article, we look at some of the practical considerations in saying yes or no to mating ewe lambs.
Extra management required
From a practical viewpoint, a few key questions need to be answered before deciding to mate ewe lambs:
- Can I manage ewe lambs as a separate group for appropriate nutrition from pre-mating right through to next year’s breeding season?
- Am I happy to lengthen my overall lambing period?
- Can I provide the labour and supervision required at lambing as well as having adequate facilities?
You need to be answer yes to all three to consider mating ewe lambs.
Ewe lamb liveweight at mating
This is a critical factor with a good rule of thumb being the ewe lamb being at least 60% of their potential mature weight when being joined with the ram. If the typical mature weight of say Belclare cross ewes is 75kg, then ewe lambs need to be over 45kgs at joining. Some more terminal sire breeds would have an 85kg average mature weight, meaning they need to be 51kg plus at mating time. As well as carrying out the usual physical checks to select suitable replacements, lambs that don’t tip the scales at the required cut-off weight should not be mated.
Planning for mating
Ewe lambs tend to be susceptible to toxoplasmosis, as they are less likely to have developed any natural immunity from exposure to the pathogen. Consult your vet well in advance of mating if considering vaccination, as it needs to be ordered and administered a month in advance of joining rams.
The ram effect works well with ewe lambs to compact mating once they are kept out of sight/sound/smell of any male sheep for the previous six weeks. Then 14 days pre mating, a teaser ram or aproned ram is introduced to ewe lambs for two days and removed. If carried out correctly, 70% can be lambed in two weeks and 90% lambed after three weeks.
Mating management
It is common practise to delay ram turnout to ewe lambs for two to three weeks after mature ewes are joined. As with mature ewes, the use of raddle is recommended to monitor activity and changing the raddle colour weekly is useful in predicting lambing date.
Where possible, it is best to use mature rams to mate ewe lambs, as they tend to be more active than ram lambs in seeking ewes to mate. It is critical to select sires known for ease of lambing.
In order to avoid a prolonged lambing period, as well as having a uniform group of lambs next spring, the duration of mating for ewe lambs should be only three to four weeks. In practical terms, rams are often removed from ewe lambs on the same day rams are taken away from the mature ewe flock.
Management post mating
It is critical that ewe lambs in early pregnancy are on a plane of nutrition that allows them to continue growing and gaining weight. This can generally be achieved with high quality grass, but supplementation with 300g/head/day of concentrates may be needed in adverse weather or where grass supply or quality of grass is limited. As previously mentioned, running ewe lambs as a separate group right through to next year’s mating is key to the success of the system. It is important to pregnancy scan and use the results to plan the appropriate late pregnancy feeding regime.
OviCast podcast
Dr Tim Keady featured on an episode of the OviCast podcast to discuss joining ewe lambs and some of the factors that influence its success. Listen in below:
Also read: Sheep farmers' views on labour wanted