Start now for mid-season lamb
On large-scale lowland farms, there should be no problem in using one mature healthy ram for every 60 to 70 ewes, provided there are at least two to three other mature rams in any group.
A well-grown ram lamb can mate around 40 mature ewes without any problems. When purchasing a ram, you should opt for a pedigree ram with a high star rating in the Sheep Ireland index system.
Dr Nóirín McHugh, Teagasc, suggests key reasons to go for a five-star ram:
* Less labour at lambing: on average, five-star rams experience less lambing difficulty, relative to rams of lower star ratings.
* More lambs: five-star commercial ewes recorded in the Sheep Ireland system have been shown to have a higher number of lambs born.
* Greater growth rates: analysis of Sheep Ireland commercial data shows that five-star lambs are on average 1.2kg heavier than one-star lambs at seven weeks of age; this resulted in heavier five-star lambs at weaning (33.61kg), relative to one-star lambs (32.42kg at weaning)
* More efficient ewes: commercial five-star ewes, on average, had a lighter mature weight (68kg) relative to one-star (71kg). At similar levels of production, this will enable increasing the number of ewes in a given flock.
* Long-term gains: genetic improvement is permanent and cumulative, so breeding decisions that you make today will impact future generations of animals in your flock.
For example, if you were to use animals with “good genes”, then the effects of these “good” genes will remain in the flock, but the reverse is also true!
Selecting a ram on stars alone is not recommended; it is important to look at the traits that the ram excels in, but also the traits where a ram may underperform!
Accuracy values must also be viewed alongside the star values. The higher the accuracy, the more information is known about the animal, and the greater the confidence we have that their published index value reflects the true genetic potential of the ram.
It is worth considering what ram breed you will use. This can have a significant impact on the flock output for the future. A maternal ram such as Belclare, Lleyn, or one of the Leicesters (Bluefaced or Border) is used to produce prolific replacements.
A terminal ram is used to produce lambs for slaughter. The most widely used terminal breeds include Suffolk, Charolais and Texel, with Vendeen and Beltex also being popular.
The proportion of the flock that needs to be mated to a maternal sire breed to ensure enough replacements are born depends on your weaning rate.
At least 10 weeks pre-mating, examine rams to allow enough time to improve body condition, address any health problems, and buy replacements and allow these acclimatise to their new surroundings and conditions.
