Farm Ireland

Thursday 18 January 2018

Rams arrive at Lyons to start progeny test


Dr Tommy Boland

As the year progresses, lamb growth rates will slow down. Over the past fortnight, growth rates have slipped to 160g/day at Lyons.

There are a number of reasons for this; the highest performing lambs have been drafted at this stage, many of the lambs remaining in the flock will be twins and triplets, which have inherently lower growth rates, and grass quality is beginning to slip.

Twenty-six lambs were drafted last week, averaging 44kg liveweight and killing out at 46pc. Grass growth is running at about 40kg DM/ha/day.

The rams for the central progeny test (CPT) scheme began arriving at Lyons last week and training these animals for semen collection is about to begin. These rams will then be used to provide semen for the four progeny test flocks.

These are part of the Sheep Ireland breeding programme, including Lyons, where all the ewes will be bred using laparoscopic AI. All our ewes and ewe lambs were sponged yesterday to synchronise ovulation and will be mated on October 17.

The sponges will be removed on October 15 when the ewes will receive PMSG to increase ovulation rate. The ewes will then be bred to Texel, Suffolk, Charollais, Belclare and Vendeen rams. The stock rams on the farm will be used to pick up the repeats.

All replacement ewe lambs were weighed last week and they averaged 50kg. Assuming a birth weight of 4.5kg on March 12, this gives an average growth rate since birth of 230g/day from grass only. Any lamb not reaching 45kg was removed from the replacement flock and will be slaughtered when finished. The exceptions to this are our mules, grey-face and half-bred ewe lambs, which we don't mate as lambs, and they will be carried over and bred as hoggets.


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On the vast majority of farms, the litter size next spring has been pre-determined at this stage through the ewe breed type and body condition score, with little scope to change either for mid-March lambing. Obviously, management in early pregnancy will still have an impact on conception rates and during late pregnancy on lamb birth weight and vigour.

While the decisions for next year have been made, the longer term can still be influenced by our actions. The recent Food Harvest 2020 report sets a target for a 20pc increase in the output value from the national flock by 2020. This year's price increase has taken care of a lot of this target, but anybody involved in sheep production will understand the price volatility that exists.

Looking at the national sheep flock, there is still a lot of spare capacity. Data from the national farm survey indicates that the stocking rate and weaning rate on the top one-third of farms is only 8.7 ewes/ha and 1.37 lambs/ ewe respectively.

Despite this relatively modest performance, gross profit per hectare on sheep farms would stand up well against most beef systems. Our lamb output is about 0.2 lambs weaned/ewe lower than that in Britain and it has not really changed since the 1950s.

There are various breeds that will give higher litter size, and even within the breeds currently used, there is great scope to increase litter size. For numerous reasons, this is not achieved.

At the launch of the Teagasc Sheep Research and Knowledge Transfer Programme, increased collaboration throughout the industry was highlighted as being critically important in addressing these issues.

Philip Creighton outlined his stocking rate study, to address the optimum stocking rate for ewes of medium and high prolificacy, while we at Lyons are going to examine optimum rearing strategies for triplet lambs, something often cited as a concern as well as determining the intake and production potential of high prolificacy ewes at grass.

Alan Fahey is also examining the potential to select for ewes that will consistently give birth to twin lambs, aimed at reducing the variability within some of the more prolific ewe types.

This work, while only a brief snapshot of the research plans outlined, represents a joint effort within the sheep industry. Many stakeholders have had the opportunity to influence these programmes, further signifying the more coherent approach now under way.

Dr Tommy Boland is a lecturer in sheep production at Lyons Research Farm, UCD. Email:

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