Sheep farmers have been advised to pay particular attention to the ewe lambs they choose as replacements on their farm.
At a recent Teagasc BETTER Farm Sheep Programme walk, Teagasc’s Michael Gottstein touched on the important factors farmers need to consider when selecting replacements.
“You need to be thinking about a breeding policy and how you are going to get your flock replacements,” the Head of the Sheep Knowledge Transfer Programme said.
Gottstein posed a number of questions to the sheep farmers in attendance:
- Have you a breeding policy or do the ewe lambs arrive on your farm by chance?
- Do you just go out and pick certain ewe lambs because they look nice or because they have grown well?
- Do you keep the ewe lambs that are left at the end of the year that have failed to finish?
- Do you see a fancy pen of ewe lambs in the mart and end up buying them?
- Does your breeding policy dictate what ewe lambs are keep as replacements?
For farmers breeding their own replacement ewe lambs, he said, Teagasc recommendations suggest that a replacement rate of 25% should be targeted.
“When we have gone out to farms who are signing up to the BETTER Farm Programme, we look at the age profile of the ewe flock.
“We are seeing big fluctuations; some years people tend to keep 25-30% replacements and the next year they might only keep 15%,” he said.
Keeping a consistent replacement rate is important, he said, as it allows farmers make culling decisions and remove any under-performing ewes from their flock.
Another important area that the Teagasc representative touched on was ram choice. This can vary from farm-to-farm.
“It’s important that rams deliver females on the ground that are going to do the job – whether that’s milk yield, number of lambs, good feet or udder placement.”
As 50% of the resulting lambs will be rams, it’s important that the ram also carries some terminal traits to ensure that these are easily finished.
Steps to identifying replacement ewe lambs
Selection starts before the ewes go to the ram, Gottstein said.
“You need to pick out the ewes that you want to breed replacements from and you also need to choose a ram that is going to bring the genetics that you want.”
On the number of ewes joined to the ram to breed replacements, he said: “The percentage of lambs that you as a farmer need to breed is a function of your litter size. The lower the litter size of your flock, the higher the number of ewes you need to breed.
“We would generally recommend that you need to keep about 25%+ replacements every year. If you have a very high litter size you will probably get away with breeding 30% of your ewe flock to maternal sires,” he said.
Once the ewe lambs are on the ground, the next step is to identify which ones may be suitable to keep as flock replacements.
This animals can be identified at birth through the use of a marker tag or ear notch.
Lambs that come from high-genetic rams and prolific ewes should be identified.
“The important thing is to identify lambs at birth that are born unassisted; get up and suckle; and are born to ewes with good milk and mothering abilities. It’s also important that they have the required genetics.”
At weanling, he said, farmers should choose the best of the lambs identified at birth to become future replacements. Those that are consistently lame, have insufficient growth rates or a dirty for long periods should be avoided.
“At weaning time, you are going into pick lambs that have grown very well. If you are mating ewe lambs,you want to pick lambs with a minimum liveweight of 45kg at six-months-of-age,” he said.