Bob Hendershot State Grassland Conservationist
(Originally Published in Sheep Team Newsletter April 2003)
What is lambing like, for your sheep flock, hours per lamb or lambs per hour? The shepherd’s labor and the size of the lambing barn are the two things that limit the size of most Ohio sheep flocks. Pasture-lambing avoids both of these concerns.
Pasture-lambing is the lambing of ewes on pasture where the ewes and newborn lambs bond without being penned or housed. Pasture-lambing works the best in concert with the peak pasture growth. Spring and fall pasture growth can provide the quantity and quality of feed that the ewe will need during the last part of gestation and early lactation. This greatly reduces the feed cost compared to winter barn-lambing. The pasture provides excellent ventilation and sanitation for the lambs. There is no manure to handle or bedding needed. The late spring lambing season concentrates the lambing into one heat cycle so 90 to 95 percent of the lambs are born within a 17 day window. Expansion is limited only to the forage supply, not to housing or labor.
Weather can be a concern with pasture-lambing. Cold, windy and wet conditions without shelter can be hard on new born lamb survival. Lambing should be planned to start when the chances of favorable weather are greater. Planning to lamb in pastures that have natural windbreaks and sheltered areas especially from the wind would be beneficial if a storm would occur. In bad weather ewes will often go to sheltered areas to lamb. Tagging and recording individual lambs and ewes is more difficult on pasture than in the barn. Pasture-lambing lends itself to commercial operation more so than to pure bred registered flocks.
A Michigan State study showed lamb losses to be similar to barn-lambing. Lamb loss for pasture systems is greater from predators. Black vultures, coyotes and maggots are the main predators. Late season docking and castration can coincide with fly season. Guard animals and other predator control management measures will be needed in most areas.
The grazing system needs to encourage the ewe to stay in her lambing area for one to three days. The are several things that can influence the ewe’s behavior that the shepherd can control. She needs to have enough forage available to her within her 10 to 12-foot diameter lambing area. She needs to lamb when the pasture forage can also provide her all the water she will need for the 1 to 3 days she will be bonding with the lambs. Minimize the disturbance from young inexperienced ewes and older “granny” ewes. Separating the ewe flock into lambing groups is helpful. Lambing first timers as one-group and older granny ewes that try to adopt lambs before they give birth in another group. Granny ewes and poor mothering skills are reasons enough for culling on most pasture-lambing farms. Separating multi-birthing ewes from singles will allow you to put those ewes carrying twins and triplets on the pastures with the most forage growth. The bonding of a single lamb and its mother will take less time thus less forage will be needed for that ewe. Try not to rotationally graze the ewes during the lambing process. Moving the ewes and the newborn lambs will cause confusion and can break the bonding process.
Set stocking a group of ewes in a paddock just before the lambing process and allowing them to lamb on their own. The amount of available forage needs to match the number of ewes and the length of their stay. They should stay a minimum of three weeks. That should allow enough time for the last ewe that lambed time to bond.
Drift-lambing is another pasture-lambing management system. The flock continues the prelambing pasture rotation, but as lambing begins, the ewes that have just lambed are left behind in the pasture where they lambed, and the pregnant ewes are moved on to a fresh pasture paddock every one to three days. Drift-lambing allows for more interactions with the lambing process including tagging and marking individuals. Drift-lambed ewes must tolerate handling of their lambs without running off. This system also allows you to intervene when bad weather or predators may cause a problem. Drift lambing requires a higher degree of skill in both pasture management and sheep handling.
Ewes that have lambed in the barn and born in the barn and bonded in a lambing jug will take some adjusting to lambing outside. They will have the tendency to go back the barn to lamb. Offering the ewe other structures will aid her in feeling more comfortable. Snow fence in the lambing pasture offset every 10 to 12 feet will give her some comfort and her lambs protection from the wind. Good mothering ewes will adapt to pasture-lambing very easily. A ewe that is getting ready to lamb in the barn or on pasture will try to isolate herself and bond .