The most common way of producing lambs everywhere in the world is once a year. Traditionally that is putting the rams in with the ewes (joining) at a time when the lambs will be born at the end of winter and have better pasture growth ahead of them. Sheep naturally cycle to fit this type of system and are more difficult to get pregnant (in to lamb) outside this natural timing.
Then there are breeds of sheep that generally originate from the tropical regions, that can cycle at any time of the year. They respond very little to changes in day length. Various schemes have developed over the years utilising these breeds of sheep to produce lambs more often. The most common one of these is the 3 lambings per 24 months - ie every 8 months. Another system is the STAR system where it tries to have lambing five times every 3 years.
We began on Caluka Farms with a similar system to the 3 times in 2 years, though a little quicker than that. The problem with it is that there will be times when lambing occurs at the worst time of the year. For us, we have two "not-nice" periods. These are January-February when it is dry and hot, and June-early August when it is cold and wet.
Fortunately we farm in a region where we usually have two springs. It usually begins to rain in March and from then until mid-May, conditions are usually spring like in pasture growth and temperatures can be hot in the early stages to mild and cool the later we get into May. Then we have the normal spring period which for us is late August to early December. This is when most of the pasture growth occurs and there is usually good moisture, and day-lengths and temperatures are increasing.
So in an effort to try and lamb at the beginning of each of these springs, we have entered into the system of lambing twice every 12 months. Gestation is five months. The maths does not work out to have lambs being born at the beginning of the normal spring (late August), but we are setup now to achieve the following dates.
Rams in: 30th Oct - 4th December. Lambs born 25th March - 29th April.
Rams in: 30th April - 4th June. Lambs born 22nd Sep - 27th Oct.
This is using a 35 day joining period each time. 17 days is the average time a ewe will cycle, so two cycles plus one day is 35 days. It is possible we might shorten that to 25 days, but we will let this plan A run for awhile and see how well it works out. We've had lots of doom and gloom comments from visitors, but the first results are in.
So, we have two main mobs of ewes. One we call the Cleanskins because they are near 100% hair sheep or 100% shedding. The other is what we call our Mixed ewes. These are ewes that have more hair/wool remaining on them than we deem necessary to be put into the Cleanskins.
We do have one other large mob and that is the maiden ewe lambs and any dry ewes. We call this mob the Drys. At scanning, these will be drafted into the Mixed ewes, Cleanskin ewes, and Drys (for the maidens, not for the older ewes as they will go to the Culls).
So, in March/April 2022, the Mixed ewes and Cleanskins lambed. We put rams in whilst the last ewes were still lambing. These ewes marked lambs at 120% for the Mixed and 123% for the Cleanskins. Approximately 50% of these ewes were scanned to be wet (in-lamb) again and those have just lambed.
On 19th November 2022, these ewes had their second batch of lambs marked. The Mixed ewes were ~120%, and the Cleanskins 140%. So, those Mixed ewes who lambed twice in the year, produced 240%/year lamb percentage at marking, and 263% for the Cleanskins.
These ewes are in really good condition, the feed is plentiful and they and their lambs are growing really well. The rams have been back in with them for a few weeks now so that the ewes will lamb again in March/April 2023.
The 50% of ewes who did not get back into lamb after lambing in March/April 2022 are also currently with the rams to lamb again in March/April next year. So those ewes are currently running at 120%/year lambing for the Mixed ewes and 123% for Cleanskins. We will see how they perform next year. Because of their excellent condition, good pastures and processes in place to prevent the “not enough starch” scenario again, we are expecting to get >90% into lamb (including the maiden ewe lambs as they are in very good condition and growing rapidly), and better than 130% lambs at marking.
So, a very pleasing result for our first year at trying this. I might have to raise my expectations. We should be able to get >80% of the "twice a year ewes" into lamb as we progress and selecting ewes who can do this, and rams bred from this system. And if we can average 250% lambing from them, then that would be a great result. Watch this space.