No, I am not referring to your trusty Kohler or Toto. Flushing is shepherd lingo for increasing a ewe’s nutrition in the weeks leading up to breeding in order to trick the ewe into releasing a larger number of eggs. Most of the sheep literature we have read, and a number of Soay breeders we know, report higher multiple birth rates if flushing is part of the pre-breeding regime. The concept is straightforward: ewes ovulate more readily and release more eggs if their bodies sense that times are good, that food is plentiful, and so it seems a good opportunity to raise a larger litter. As I understand it, commercial breeders use flushing routinely. They must have a high ratio of multiple births to make sheep-raising financially viable.
Here is how it works from the shepherd’s standpoint. Two weeks before you put your breeding groups together, start feeding your breeding ewes a little something extra along with their normal diet of grass or hay. We use a product called “ewe/lamb ration” from our favorite feed store. It is 14 % crude protein. COB (corn, oats, barley) or other pelleted feed with 9 % crude protein is another alternative. If you don’t mind the hassle of soaking beet pulp pellets (also 9% crude protein) every day, you can use that as well.
The goal is a gradual and modest increase in the ewes’ “nutritional plane” — to boost them slightly from where they start. If they are already fat, flushing probably will not help and it might be counterproductive, because really fat ewes are reported to have lower fertility rates. But if your ewes, like ours, are starting to complain about the quality of the late-summer grass in your fields, or you are down to the last few sorry bales of last year’s hay, the increased nutrition should have the desired effect.
We start with 2 ounces per ewe per day and gradually increase that amount to 4 ounces by the end of the first week. You do not want to change your ewes’ diet abruptly for at least two reasons: their rumens need to adjust to the change in composition of the material to be digested, and apparently if the new stuff passes unprocessed into the intestines, the ewe is at risk for scours. In other words, ramp up rather than change abruptly.
How do these numbers play out? Here are a few examples:
# ewes Days 1&2 3&4 5&6 7 8-14
1 2 oz 2.5 oz 3 oz 3.5 oz 4 oz
4 8 oz 10 oz 12 oz 14 oz 1 lb
8 1 lb 1 lb 4 oz 1 lb 8 oz 1 lb 12 oz 2 lb
Stay at the increased level for a second week (days 8-14), then put your your ram(s) with your ewe(s) for breeding. On the day you begin breeding, start tapering off the goodies gradually until you quit supplementing them at all after two more weeks. In other words, four weeks total of supplementation, gradually up, gradually down.
For the same reasons flushing is designed to increase the number of ova released, it also encourages the ewes to start ovulating a little sooner, which may put them in sync, and that in turn may concentrate your lambing so it does not drag on for weeks.
Most books recommend a second trick to get your ewes ready for action, i.e., getting them to cycle well. If your pasture situation and prevailing winds allow it, place your ewes near or at least downwind from the rams. The smell of the rams (and believe me, they smell at this time of year) helps trigger cycling, as does the shortening of the days. If you can put your ewes in a location adjacent to your rams – a stout fence and a view block separating them – all the better. That way, the rams also can smell the ewes and get charged up. But – and this is crucial, you must have sturdy fence and you really should use view blocks.
Will you agree with me that these pictures of some of our 2008 twins provide yet another reason to flush your ewes — the sheer pleasure of looking at the little ones together?
If you flush your ewes, you’d best get your lamb kit ready because before you know it, lambs will begin arriving two by two to entertain you.
For now …