Farm Ireland

Thursday 22 March 2018

Ensure ewes are in good body condition when off to the ram


Andrew Kinsella

Whether it is the higher flock replacement cost or perhaps the prospect of good lamb prices again next year, sheep farmers seem to be more focused on flock mating management this year.

More on this later, but the first question that each sheep farmer should ask is "what is the most appropriate lambing date for my situation?" May and June lamb prices over the past few years are still insufficient to cover high concentrate feeding costs. This means that you should aim, instead, to have your lambing date coinciding with spring grass growth.

It does not make sense to lamb in early February and then to run out of grass resulting in costly meal feeding and still only secure July lamb prices.

There is possibly a place for farmers with a low sheep stocking rate to lamb early, but always consider the impact of this decision on grass supplies and the impact it may have on other follow-on grazing stock. It is also worth remembering that (in the absence of sponging) an earlier lambing date is generally associated with a longer lambing spread.

I had several phone calls last January about low litter sizes and high numbers of barren ewes at scanning. Some of these cases, especially with younger ewes and ewe lambs, may have been due to toxoplasmosis and the low availability of the vaccine last year but I am convinced that a good number were due to ewes being in poor condition at mating.

Ewes should be have good body conditioning going to the ram, with a condition score of 3.5-4.0. Ewes in poor condition should be given preferential feeding and those that do not recover over an eight to 12 week period should be culled. Ewes in poor condition will respond to flushing (good grass for 3-4 weeks pre-mating and during mating) by having an increased ovulation rate and litter size.

However, in my experience, particularly with mating from mid-October on, ewes in poor body condition (while responding to flushing) are unlikely to gain sufficient weight coming into the winter and are most likely to be in poor condition at lambing time. Looking back over the past years, the one group of sheep that I find to be neglected most are hogget ewes (two teeth) that have been retained as replacements but not mated in their first year.

They are often fed forage only during the winter months, put well away from the yard on one of the poorest fields for the summer, treated with a long acting pour-on for fly control and left to their own devices until August, when they are joined with the flock.

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Their comrades which have been bred as ewe lambs or which have been retained for the ewe sales often fare better. Hogget ewes should be at least 80pc of mature weight, or around 65kg for most flocks, at mating. In summary, ewes should be in good body condition going to the ram and should be maintained on good pasture during the mating period and for about four weeks afterwards.

In our own situation, we operate a closed flock and ram lambs are the only animals that are purchased. They are dosed and vaccinated with Heptavac P+ immediately on arrival and a second vaccination is given four to six weeks later. Like the ewes, rams must be in good condition before the start of mating.

Other pre-mating practices routinely carried out include:

•Vaccinating hogget ewes with Toxovac.

•Dipping all animals during September every second year to prevent infestations of lice and ticks. Vetrazin and Click act specifically to prevent blowfly and have no activity against lice and ticks.

•Inspecting the feet of all ewes and rams at least one month pre-mating, paring if necessary and then foot-bathing.

•Dosing the ewes with cobalt sulphate three weeks before ram let-out and again at let-out. Wicklow is well known for being cobalt deficient.

•Using the ram to compact mating. The rams are removed from the ewes around six weeks pre-mating and are then reintroduced 14 days before ram let-out into a field adjoining the ewes but separated by electric fencing. Some people would argue that this is unnecessary as all our ewes should already be cycling by the time we are letting out the rams on October 21. But I believe it has some effect and it does not cost anything.

•Raddling the rams at let-out by pasting the brisket. This is to ensure that rams are mounting the ewes and that mating is progressing in a normal fashion.

Andrew Kinsella, former sheep specialist with Teagasc now sheep farming in Wicklow

Indo Farming

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