Winter Conference Workshop Preview: Accelerated Lambing and Selective Breeding
December 20, 2012 -- Webmaster
This article comes from the NOFA/Massachusetts 2012 December Issue Newsletter
By Sam Anderson
A heavy January snow is coming down as you roll down the driveway. You are on your way to a nice evening party, the kind you need to dress up for, and you feel like you’re looking pretty sharp for a sheep farmer. You instinctively look out the window at a group of ewes as you pass, the ones scheduled to lamb in May. One ewe is standing out in the snowy field by herself, sniffing at the ground. Your heart sinks: this can only mean one thing. The party will have to wait.
Ten minutes later you are out in that field, bundled up in your barn clothes and coveralls, carrying two nearly-dead lambs back to the barn as their mother follows. There aren’t any pens open for them—those are all occupied by the ewes that were supposed to lamb in January—so you set the frozen lambs on a towel in the hallway, dry them off, set up a heat lamp, mix up some warm colostrum, and feed it to them through a stomach tube. After an hour, with numb fingers and toes, you finally watch the lambs sit up, revived, as their mother licks at their backs. Alright then, you think: off to the party!
Lest I appear to be overselling the benefits of accelerated lambing in the following paragraphs, take the above (a true story—that partygoer was my mom, 20 years ago) as a disclaimer: If you want to get into accelerated lambing in the Northeast, this is what you’re in for.
On most New England sheep farms, ewes follow a pretty regular annual schedule: lamb in the spring, nurse your lambs until late spring or early summer, and then take it easy until breeding season rolls around in the fall. This is generally the easiest, most straightforward system for the sheep and the farmer, and only partly because you don’t have to mess with winter lambing. Unlike many domesticated animals, sheep and goats’ breeding cycles are still very seasonal. Without human interference, a ewe’s biological clock will tell her sometime in late fall that it’s breeding season (the ram’s biological clock is a bit less picky, believe it or not), so that her lambs will be born about 21 weeks later, after the threat of winter weather.
For many breeds of sheep, this calendar is somewhat hard-wired, and the farmer may not have much choice but to have a single spring lambing season each year; but there are some breeds which are more likely to successfully breed out of season, such as Dorsets, Merinos, Polypays, Katahdins and Finnsheep. Producers raising these breeds can select for “non-seasonality” as a production trait to encourage it in future generations. This opens up the possibility of having a winter or fall lambing season—and the possibility of having lambing seasons in winter, spring and fall. This is accelerated lambing: a system involving multiple breeding and lambing seasons, enabling each ewe to at least occasionally lamb twice in the same year.
Now, thinking back to the first paragraph, a valid follow-up question here would be: “But why?” Why would the sheep farmer voluntarily subject herself to three or even five lambing seasons every year? Wouldn’t you want to avoid having to go out to the barn at night during a blizzard? There are other concerns, too: Won’t this be hard to pull off without feeding at least a little bit of grain or really high-quality hay? Won’t I need to have a barn or other shelter for winter lambing? Won’t I need to do more recordkeeping? (Yes, yes, and yes.)
Accelerated lambing is not for everyone. It involves more work, more management skill, and more feed costs. But it also involves more lambs, which means more profit—without having to expand the flock. For the farmer who is serious about tracking and improving flock genetics, it also means more data, which leads to faster improvements in traits like growth efficiency, mothering success, or inherited resistance to internal parasites.
This is all accomplished by shortening the amount of time between a ewe’s lambings. For example, whereas a ewe is expected to lamb once every 12 months in a regular single-lambing system, she might be expected to lamb once every 8 months in a three-season system (e.g. February, June, and October lambings). The goal is for the ewe to lamb three times in two years, or an average of 1.5 lambings per year. The more intensive five-season STAR lambing system, developed by Cornell University, asks ewes to lamb even more often, with the goal of five lambings in three years (1.67 lambings per year). When these systems work, they pay dividends; but it’s not easy. When I say that STAR lambing “asks” ewes to lamb five times in three years, I mean that. Through careful planning, management, and genetic selection, you can ask a ewe to lamb more often—but you can’t tell her to. Ultimately, it’s up to the ewe’s body to decide; all the farmer can do is make the conditions as favorable as possible.
So how do you make it work? And how do you decide whether accelerated lambing makes any sense for you? For that, you’ll have to come to the Accelerated Lambing and Selective Breeding workshop at the NOFA Winter Conference on January 12. If this falls in the middle of your own January lambing season, don’t worry: you don’t need to dress up, and we won’t mind if you show up smelling like the barn.
Sam Anderson is the Livestock Program Coordinator at New Entry Sustainable Farming Project and will be presenting Accelerated Lambing and Selective Breeding at the NOFA/Mass Winter Conference at Worcester State Universiry on Saturday, January 12, 2013.