Mating ewe lambs on the BETTER sheep farms

Lambing replacements ewes as one year olds presents an opportunity to offset some of the replacement cost through an increase in flock output. However, following a difficult grazing season, many producers may have taken the decision not to join their replacements this year.

When managed correctly, yearlings are capable of delivering greater than 0.75 lamb reared per ewe lamb joined.

However, mating ewe lambs may not suit every producer as it requires extra management during pregnancy and post lambing to achieve high levels of lamb performance and ensure the yearling ewe has an opportunity to grow and reach 85% of her mature weight as an 18 month old.

Three of the farmers involved in the BETTER Farm sheep programme – Brian Nicholson, John Kelly and John Curley – have opted to continue to join either all or a proportion of their replacement ewe lambs. With mating nearly finished on these farms, details of what they have done with this year’s ewe lamb flock and some pointers on their management are described below:

Brian Nicholson, Co Kilkenny

All 300 ewe lamb replacements were joined on the 12 October with three mature Ile de France rams for a four week joining period. This year’s replacements were comprised of homebred Texel x Mule (71%) and purchased Belclare x Mule (29%). All replacement ewe lambs were shorn in late August.

John Kelly, Co Wicklow

All 162 ewe lamb replacements retained this year were joined with theree mature Charollais rams, two mature Suffolk rams and one Belclare Ram on the 14 October for a four week joining period. The replacements this year comprised of Belclare-X (70%) and Suffolk-X (30%). These lambs will be shorn at housing in December.

John Curley, Co Roscommon

This season 62 ewe lambs were retained, these were either Belclare-X (60%) or Suffolk-X (40%). From these, the 30 heavier, predominantly Suffolk-X lambs, were selected for mating and were joined with a mature Charollais ram on the 18 October for a three week joining period. These lambs will be shorn at housing in December.

For the three flocks, all ewe lamb replacements were weighed and had their condition score assessed before joining in October. Their weight and condition score at joining is summarised in Table 1.

Mating Management

In all three cases the ewe lambs are managed separately to the main flock during the joining period. In each of the cases the end of the joining period will coincide with that of the mature ewe flock. The farms avoided extending the joining period for ewe lambs into December as it would have had a negative effect on the following season.

The threshold weight which ewe lambs need to attain to reach puberty reduces as the season progresses. In early October the minimum threshold weight to attain puberty is 44kg, by early November this is reduced to 40kg and by early December this drops to 33kg. Therefore, in a situation where all replacements are joined, delaying mating until late November will result in a larger proportion of the lighter ewe lambs being mated. This is not desirable.

Allowing the lambing period to extend into late April/early May will invariable reduce the dry period for the yearling ewe the following year. This, in turn, will reduce the time available to reach the target body condition and target weight prior to joining as 18-month-old hoggets. Additionally, there will be a greater proportion of lighter lambs in each of the systems later in the year by virtue of them being born later.

Experience from previous years

Over the past two seasons we have examined the effects of mating ewe lambs on their weight and body condition score the following autumn as hoggets. Replacement hoggets that lambed as yearlings were 5kg to 7kg lighter and had a condition score of 0.25 to 0.5 less than those that were not mated as ewe lambs. These results emphasises the need to ensure that yearling ewes and rear lambs need to be placed on a good plane of nutrition, not only throughout the later stages of pregnancy and rearing period but also during the post weaning period. The effect on reproductive performance will be examined in the coming season – however, it is expected that the reduction in weight and condition will have a small negative impact on litter size when lambing as two year olds.

Details of the management of these ewe lambs during pregnancy will be presented and discussed in subsequent articles. Additionally, each of these flocks are available for visiting groups during the coming season.

* Ciaran Lynch, Teagasc, Animal and Grassland Research and Innovation Centre, Mellows Campus, Athenry, Co Galway.

Preparation for housing

Darren Carty

Livestock reporter

Poor grass growth and difficult grazing conditions have significantly reduced the length of the grazing season. This week’s Irish Farmers Journal survey shows 43% of respondents will run short of grass in the next 10-20 days while a further 29% will run short of grass by the end of December. While it may be tempting to run ewes over the entire grassland area to prolong the grazing season, doing so will have greater repercussions next spring.

This is because it will cost significantly more to supplement ewes and lambs at grass post lambing than it will to introduce supplementary feeding to ewes in the weeks ahead.

Housing is not an option for all flockowners but even where housing is not available it should not be a reason to give animals’ access to the entire grazing area.

In this case, ewes should be tightened into a defined area where silage/hay or concentrates can be introduced. Where there is access to rough grazing or ewes are grazing hill areas, introducing feed buckets that will also provide minerals can be considered. These buckets, in some cases, work out more expensive than supplementing with concentrates but lend themselves to reduced labour. Housing at this stage will also mean animals will be housed much earlier and for considerably longer than previous years.

Take account of this when calculating the volume of fodder and straw bedding required. In general, a 4x4 round bale weighing about 140-150kg will be sufficient to bed 18-20 lowland ewes or 30-32 hill ewes each week. It is also worth considering footbathing facilities to keep feet problems to a minimum. Race footbaths will cost approximately €150 while a stand-in footbath will cost from €600-€700. Grant aid is available on mobile batch footbaths at 40%, to a maximum spend of €654.02 excluding VAT.

A longer housing period has the potential to increase the risk of disease occurring and spreading if the correct precautions are not taken. Where not already undertaken, sheds should be power washed and disinfected before housing.

Spreading hydrated lime before bedding the shed and also at regular intervals will help limit disease spreading. Ensure ewes have sufficient feeding space of about 200mm where feeding forage ad-lib and increasing to 400-500mm where forage is restricted.