By Denice Rackley
Few things are more satisfying to livestock producers than witnessing new life begin. Slimy, soaking wet, wobbling legged lambs who nose dive as they attempt to stand. Finally, on their feet nuzzling the wrong end of mom in search of the fist meal – we anticipate the arrival of lambs for months.
Autumn’s crisp mornings will arrive before we know it, the cool breezes and increasingly earlier sunsets remind us summer is on the downhill slide. Each fall sheep producers are faced with a decision that impacts every other choice for the next year – “When should I put a ram with the ewes?”
“From a profitability standpoint the single most important decision you can make is when to lamb. That is because the costliest animal to feed is the lactating ewe,” says Dr. Bob Leader, DVM.
Lambing generally falls into two categories – shed lambing in winter or pasture lambing in spring. There are breeds of sheep you can manage intensively to have multiple lambings in a year, and some sheep breeds will successfully lamb in the fall, but this discussion will deal with lambing one a year in the more traditional lambing seasons (Dec-May).
Ewes begin to cycle as day length shortens. Most ewes have two heat cycles a month (every 15 to 18 days for 24 to 48 hours) and will lamb in about 5 months (average 128 days). Deciding when lambs should be born will tell you when the rams need to enter the ewe pasture.
How do you make a choice between winter and spring-born lambs? Let’s look at some of the pros and cons of both systems. In the Midwest, winter lambing means lambs will need to be born in a barn or at least have access to shelter, while spring lambing can be accomplished on pasture.
The most significant advantage of winter shed lambing is that every part of the process can be managed, and the flock is close at hand to make management more effortless. Pasture lambing, when ewes are out grazing, means they have feed at their feet. Chores are simpler, but intervention and management are not as easily accomplished.
Shed lambing is more labor-intensive. Feed and water are brought to ewes and pairs housed inside. The barn is bedded and cleaned. Families require adequate space so new mothers can separate themselves and their lambs from the flock to enable bonding and decrease the chance of mis-mothering.
Once a ewe has lambed, she and her lambs are moved into a separate pen or jug. The ewe can be observed making sure she accepts all the lambs; her bag can be checked, ensuring she has two functional teats and sufficient milk supply. Tail docking and taggings are easy while lambs are penned. Bonding occurs without the possibility of interference. Most producers who use jugs, allow the family to remain for 24 hours. If there are triplets or problems, the family can stay longer. The family is then moved into a mixing pen that holds several families of similar ages for further bonding. This slightly larger area ensures the ewe and lambs can locate each other, and all is well before moving them into a paddock with more families.
Shed lambing also works well for bottle-lambs, which are an inevitable fact that accompanies raising sheep. Bottle or bum lambs need a well-bedded draft-free pen separate from the ewes and lambs. Once trained to a bottle, they don’t require much extra time, their bottle can be hung for them while you do other chores. Bottle lambs can be introduced to grain early. Growing well on grain will reduce the chance of bloat and reduce cost since milk replacer is expensive.
Shed lambing systems are, by their very nature, labor-intensive. Checking ewes and lambs every couple of hours, carrying feed to individual pens, and cleaning and bedding pens require time. Mis-mothering potential is higher because ewes are unable to distance themselves and their lambs very far from other ewes. Mortality is typically highest in the lambs’ first 30 days, so keeping a close eye on lambs and ewes can be beneficial and allow early detection and intervention if problems arise. Shed lambing can increase the chance of mastitis in ewes and pneumonia and scours in lambs, but keeping the barn clean, draft-free, and not overcrowding improves health and mothering ability of ewes.
Reduced cost of infrastructure is possibly the most significant advantage to pasture lambing. Flock size is not limited by how many ewes can be placed inside during lambing. The largest hurdles for those considering pasture lambing are the weather, depending on the ewes to take care of the lambs without much assistance or intervention, and the increased chance of predation. Mothering ability is genetic. If we keep marginal ewes and their ewe lambs, we increase the work for ourselves. Pasture lambing makes those marginal ewes easy to pick out and cull problems from the flock, making our flock more self-sufficient.
Waiting until soil temps are above 45 F, and there is plenty grass available for the ewe and her lambs to remain where she chooses to give birth, will add to your success. Having shrubs or woods for a windbreak and shelter is a great asset. In parts of the east and Midwest where spring rains can last for days, more substantial shelter may be needed. Natural shelter is usually sufficient for newborn lambs, though a contingency for foul weather is helpful. Lambs can withstand cool or even cold temperatures if they have a full belly, but continual rain can lead to health problems.
Checking for new lambs fist thing, through the day, and at dusk is typically sufficient to catch any problems that may occur. My personal experience is ewes that are kept on pasture all year, will birth lambs right before dawn, and during daylight hours as natural adaptation to avoid predation.
Lambing in the spring takes advantage of improved fertility for both the ram and ewe. Delaying breeding until the middle of the breeding season can result in a 5 to 10 percent increase in the number of lambs born. Spring born lambs can benefit from spring, summer, and fall forages, significantly decreasing the cost of finishing.
Predators, parasites, and dealing with unpredictable spring weather maybe the three largest challenges with pasture lambing.
Predation and parasites can be a significant challenge when pasture lambing and raising lambs on pasture. Guardian animals are an added expense, but the added peace of mind knowing the flock is protected is well worth the cost. Guarding livestock is instinctual behavior. Choosing a guardian from a parent who works successfully in a similar management style will give you a better chance of success. The selection and raising of a guardian is key to having a dependable watchman caring for the flock.
Parasites can be another complication when lambing on pasture. Maintaining forage levels above 4 inches will reduce parasite exposure as will rotation of pastures and allowing adequate pasture rest for your particular area and forages.
Rotational grazing and raising livestock on pasture is as much of an art as it is science. No two years are identical. Heavier soils, humidity, and high temperature will accelerate parasite pressure requiring faster rotations and longer rest periods.
The need to rotate sheep through pastures, bring individuals to a handling facility, or house them temporarily in a barn requires moving sheep. Moving the flock, especially with young lambs, can be easier said than done. The rattling of a grain bucket can turn into a dangerous mob scene with sheep pushing and shoving.
Shed and pasture lambing both have advantages and disadvantages. To choose the system that is right for you, evaluate your individual situation.