Lambs are thriving despite the mini ‘drought’ here in the east

GRASS growth at Lyons in the week to May 4 ranged from 42kg to 59kg DM per ha per year at Lyons. Our ewes are now in the eight or ninth week of lactation so a ewe plus twin lamb unit has a daily feed demand of 4.4kg DM per day. At a stocking rate of 12.5 ewes per ha, this equates to a daily feed demand per ha of 55kg DM per ha. The daily demand (ewe plus lamb) is reduced to 3.9kg DM per day if the ewe is rearing a single lamb.

April was a rather dry month for us, with rainfall of just under 20mm for the entire month, or less than 40pc of our normal for the month, so things are starting to dry out currently and grass growth rates are impacted - especially on the higher ground, with shallower soil.

This follows on from a dry March also and we only received 50pc of our normal combined March and April rainfall. None of this means we will continue to have a dry year, but it does pose some short-term challenges.

On the positive side, sheep really enjoy dry weather and especially dry grass. Lamb growth up to five weeks of age was a very respectable 325g per head per day. This is without concentrate supplementation, and with swards grazed down to a postgrazing sward height of 4mm in the first rotation.

Average ewe body condition score at five weeks post-lambing was 3.1, which was down from an average of 3.4 at lambing time. One of the keys to successful pasture-based sheep farming (without concentrate supplementation in early lactation) is having ewes lambing down in the correct body condition score (3-3.5). This gives an energy supply, which is stored within the ewe’s own body, that she can utilise to maximise the benefit of grazed grass, which is often (very) high in protein, especially where nitrogen fertiliser was applied.

My view on concentrate supplementation, is much like my view on many external inputs into our sheep production systems, ‘As little as possible, but as much as necessary’.

In other words, if something is needed, use it; if it is not needed then, don’t use it. The feedback I receive on these articles is always welcome and frequently interesting. Some observers state that I promote the overuse of concentrates, with the levels of concentrates we feed during late pregnancy, and other observers tell me that I am opposed to concentrates, by not recommending their feeding in early lactation. My opinion, which is formed on the basis of the research we and others have conducted, and on the experience of feeding sheep, is it is easier to feed concentrates to housed pregnant ewes, than it is to feed ewes with young lambs at foot, outdoors.

Grass supply

Obviously, all of this is dependent on having sufficient grass supply available at turnout to meet the demands of your animals.

Two weeks ago, we had all ewes and lambs through the handling for foot bathing and a nematodirus dose. This year we used Albex. This dose was applied based on the Department of Agriculture parasite forecast.

We have approximately 20 ewes rearing triplets at Lyons this year which is down form 50 ewes last year. Many of our ewes that would otherwise be rearing triplets had one lamb removed for another experiment. The plan is to wean these lambs onto redstart in late May/early June, depending on growth of the redstart crop which was sown approximately 10 days ago. This is an area of the farm, which does desperately need rainfall. The area of redstart sown is much greater than that required for the triplet lambs, so a section of the main flock will also use this area.

The next month will be based around maintaining grass quality and the grazing rotation, harvesting silage, and tracking parasite levels in the lambs.

Prof Tommy Boland is a lecturer in sheep production at Lyons Farm, UCD. @Pallastb tommy.boland@ ucd.ie