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Supply level of grass to decide date for weaning

Lambs born before St Patrick's Day are coming up to weaning time. Grass supply level will influence whether you should delay or advance the weaning date.

If grass was plentiful, and lambs were thriving, my inclination would be to leave lambs with their mothers for a bit longer. You can try to get more of them off to the factory before the stress and growth check that comes with weaning.

But if grass is scarce and you have some nice aftergrass, rape, typhon or stubble turnips coming available, then I'd wean.

The issue of weaning stress in calves was important enough to trigger the Suckler Welfare Scheme. Lambs too, take a setback at weaning and suffer stress and weight loss.

Even kill-out rates in the factories seem to take a nosedive once lambs are weaned.

The weaning setback is reduced if the lambs are creep feeding on paddocks ahead of the ewes, or even more so if the lambs are on a dry creep feed.

Flock owners with yearling hoggets will be anxious to wean to give the young ewes a chance to gain condition for the mating season. Still, it is preferable that even the lightest of the lambs in the flock will be over 20kg liveweight at weaning.

It is reckoned that a ewe's milk yield peaks at three to four weeks and that by eight weeks 75pc of the ewe's lactation yield will be fed. At 12/14 weeks, only the better milking ewes will be making a significant contribution to the lamb's growth.

While it might not be a prblem this month, mastitis and blind teats on the next lambing can be a problem in weaned ewes especially in hot muggy weather with lots of flies.

In bygone days sheep farmers used to milk weaned ewes in an effort to reduce the mastitis threat. I heard of one farmer with a good sheep race and sorting gates, who lets the weaned lambs again suckle the ewes one last time about three days after weaning.

Immediately post-weaning some people will house ewes on hay or even straw to reduce their milk.

This starvation can be overdone and you can trigger a type of tetany in weaned ewes.

One of the benefits of weaning is that you can tighten ewes to a confined area at over 20 to the acre. On an all-sheep farm, this is a time you can close up for a cut of silage.

Immediately after weaning the area where you put the lambs must be well fenced.

I don't like having entire ram lambs around from early to mid-September. Assuming a gain of about 1.1kg a week from early July, I would like to castrate any rams that are less than 35kg at weaning.

Even then I would like to see the rams run separately from ewe lambs. Take care when castrating in hot weather. Once the burdizzo clamps shut, open it immediately. Some people give a preventative long acting antibiotic at castration. Weaning is usually accompanied by a worm dose plus a treatment for cobalt.

Some flock owners are prepared to let their weaned ewes lose weight and condition so that the ewes can be flushed in the run up to mating.

This is reckoned to stimulate extra ovulation and increase next season's lamb crop. Others reckon that it is the condition of the ewe per se at mating that influences the lamb crop size rather than the fact that she is gaining weight.

The latest Scottish research indicates that both flushing and good condition at mating can influence the lamb crop size.

This suggests that you can tighten up weaned ewes provided they are well fleshed but that thin ewes should be put on better fare.

However, nobody wants overfat ewes at mating. They seem to be the least productive when it comes to conceiving next season's lamb crop.

John Shirley is a drystock farmer in Rathoe, Co Carlow

Indo Farming