18th May 2011

This year there have been dire warnings about mass hatchings of Nematodirus battus – a roundworm that can cause havoc in a group of naïve lambs.  Larvae that have over wintered in the soil (they can survive the hardest winter), hatch en masse during a warm spell following a cold snap, causing profuse watery scouring in lambs.

Faecal Egg Counts can’t detect them at this early stage of their lifecycle, and once the lambs are infected they can quickly die from dehydration.  To make the situation even more complex, lambs may also be exposed to coccidiosis, which has pretty much the same symptoms (but an FEC will detect coccidial oocysts).

 

 

The recommended precaution is to avoid turning lambs out onto pastures that have carried lambs during the previous 2 years, which brings me on to the subject of field rotation – a real challenge to the smallholder with limited acreage. 

At Green Farm we have 7 separate paddocks and fields, which sounds a lot until you start planning seasonal grazing for the different groups of sheep:

•  Breeding ewes + their lambs in Spring

• Replacement ewes,
  (previous year’s ewe lambs that will join the breeding ewe flock in autumn)
• Rams

… then take into account the fact that we have had virtually no rain since February  so the grass is exceedingly sparse!  In May, we shut up the hay field, so that takes us down to 6 paddocks.  Then when the lambs are weaned in September, we have two further groups to cater for:

• Fattening ewe lambs
• Fattening ram lambs (because we don’t castrate, they have to be managed separately)

Next, we have to factor in grass growth rates, and sward height: at this time of the year the ideal height for the ewes and lambs is 4-6cm, so out comes the topper when it starts getting out of hand.  Later in the year, the weaned lambs will do best on pasture that’s closer to 8cm, while the ewes will dry off more quickly on sparse pasture … until, that is, they’re ready for flushing on lush grazing!

Ah, one other factor – we have horses.  Great big horses that gallop around trashing the paddocks! 

So, you see, it can be quite a headache providing good, clean grazing throughout the year.  To add yet another level of complexity, last year we experimented with keeping some of our ewe lambs back to grow on as hogget, that is, a female or castrated male sheep between 12 – 24 months (at which point the meat from a ewe is called mutton).

It proved to be a great success, the meat was wonderfully lean, tender and flavoursome – and our customers have asked us to produce hogget again next year, as the eating quality is superb.  Great feedback, but it means more winter grazing!