If you’re running on a spring lambing schedule, then lambing season is quickly approaching. Proper preparation for lambing on your operation is critical to maximizing your lamb survival rate, and ensuring a low-stress environment for both you and your ewes. Read on to learn more, or refresh your memory, on key areas of preparation for the upcoming spring lambing season.
Pay Attention to Body Condition and Ewe Nutrition
During the last 6 weeks of gestation, approximately 70% of fetal growth occurs. Consequently, this time period is one of the most energetically demanding for a pregnant ewe. It's important to pay extra close attention to your ewe’s body condition. A body condition score of 3-3.5 is ideal. Ewes that are too fat are at increased risk of dystocia as well as pregnancy toxemia, as too much fat in the body cavity makes it difficult to accommodate a full rumen and growing lambs. As a result, the ewe cannot eat enough to meet her energy needs. On the contrary, a ewe that is too thin can also develop pregnancy toxemia and should be given supplemental nutrition to ensure that her lambs will be born at an adequate size and vigor.
The nutritional needs of a pregnant ewe vary depending on her weight and age. Pregnant ewe lambs have higher energy demands than mature ewes, as ewe lambs are growing themselves along with their offspring. In these cases, it is sometimes necessary to feed a high concentrate grain diet, though it’s essential to be mindful of overfeeding.
In addition to energy demands, pregnant ewes require extra attention to certain micronutrients, particularly calcium, selenium, and Vitamin E.
Ewe calcium requirements essentially double during late gestation. Low levels of calcium in her diet can result in milk fever, while too high of a calcium intake can cause urinary tract blockages. In general, grains are a poor source of calcium, and forages, specifically legume hays, tend to be much better. However, calcium can also be supplemented with dicalcium phosphate, bone meal, or limestone mixed into your feed.
Selenium and Vitamin E
Selenium and Vitamin E are passed directly from the placenta to the fetus during late gestation. Low levels of the two can cause white muscle disease, or muscular dystrophy, in lambs and have been linked to poor reproductive performance and retained placentas. Free choice minerals often provide adequate amounts of selenium and Vitamin E to pregnant ewes when added to their grain ration, though producers can also give Se and Vitamin E injections to newborn lambs if a veterinary prescription is acquired.
Check Your Flock Health Plan
Herd health plans should be an ever-evolving system; use previous years' records to identify critical control points and identify areas where you’ve historically experienced issues to prepare accordingly. While it's good to have general protocols in place for issues such as scours, the main areas to consider when evaluating your health plan for pregnant ewes are your vaccination plan, parasite control, and antibiotic protocol.
Vaccination Plan for Pregnant Ewes
No less than 4-6 weeks before lambing, boost your ewes for clostridial disease, pasteurellosis, and tetanus, though keep in mind that ewes that have never been vaccinated, or whose vaccination status is unknown, should receive two vaccinations during late gestation 4 weeks apart. Once vaccinated, your ewes will be able to pass antibodies onto their lambs via colostrum, which can help improve lamb survival rates.
Parasite Control for Pregnant Ewes
Due to hormonal changes and fetal demand for glucose, pregnant ewes endure a period called periparturient rise, in which they suffer a temporary loss in immunity to gastrointestinal parasites. Periparturient rise results in increased parasite egg shedding, and consequently parasite infections in the new lamb crop with inexperienced immune systems. Deworming with effective anthelmintics is, of course, an effective way to combat periparturient rise, though due to the increasing emergence of anthelmintic-resistant parasites, other methods may need to be considered. Studies have shown that an increase in protein intake can lower fecal egg count numbers (FEC), while FAMACHA and body condition scores can be used to assess the need for anthelmintic treatment, rather than taking a blanket approach to your flock. In some areas, it may also be helpful to keep your ewes and lambs in confinement or on dry lots to lower your parasite risk, though western pasture and rangeland tend to be much better in keeping parasite infections lower.
One parasite to pay closer attention to during periparturient rise is coccidia. While not a worm, coccidia is a single-celled parasite that naturally occurs in the sheep GI tract and lives within the cells that line the intestine. During periparturient rise, coccidia oocyte populations increase and lead to shedding into the lambing environment through the ewe’s feces. It may be necessary to feed a coccidiostat to reduce the amount of oocyte being shed into the lambing environment, and potentially aid in the prevention of abortions caused by Toxoplasma gondii, the single-celled parasite that is responsible for toxoplasmosis. And depending on your coccidiostat choice, it could also help increase your ewes’ rumen productivity and efficiency, enabling them to better meet their energy demands through gestation.
Antibiotic Protocol for Ewes during Pregnancy
Administration of antibiotics before or during early gestation may prevent abortions caused by Campylobacter spp. And Chlamydia spp. The FDA has approved the feeding of Chlortetracycline at a rate of 80 mg per head per day, though you must obtain a Veterinary Feed Directive (VFD) from your veterinarian. And as always, it's important to discuss antibiotic administration protocols with your vet to avoid causing widespread antibiotic resistance.
Shearing or Crutching Pregnant Ewes
Shearing or crutching, removing wool from the vulva and udders, can be done about 4 weeks before lambing. Although not 100% necessary, shearing or crutching comes with several benefits such as preventing lambs from latching onto a wool lock or tag when feeding, helping to limit moisture in your lambing facility, making ewes less likely to lay on their lambs, enabling your ewes to take up less space in your lambing barn and around feeders, and cleaner fleeces for newborn lambs. The main downside of shearing or crutching before lambing is that your ewes may require more feed to stay warm.
Prepare Lambing Barn for Lambing Season
Your lambing barn should be prepped and ready well before your first ewe lambs. You’ll need to clean and disinfect your barn and pay attention to identify and eliminate drafts. However, keep in mind that good ventilation is important to keep moisture down and maintain a clean, dry environment. Plan 12-14 square feet per lamb to avoid overcrowding, and if using jugs, enclose a space that is at least 4’x4’ and made of temporary fencing at least 3’ high. Provide clean, dry bedding, and double-check that all lightbulbs are working properly.
If pasture lambing, ewes should be placed on clean, well-rested pasture with access to shelter. In this case, it's still a good idea to set up jugs for problem births, and if possible, plan to rotate pastures after a period of lambing to keep new lambs separated from older lambs to prevent infection.
Stock Up with Equipment and Supplies
Before lambing season begins, it’s a good idea to take inventory of your lambing supplies and identify areas where you’re running low. Ensure you have enough disinfectant, iodine, castration rings, feeding tubes and bottles, marker sprays or chalk, sterilization equipment, milk replacers, colostrum replacers, medicine, etc. And remember that it's necessary to have good lighting in your lambing barn, so check your lightbulbs and stock up with extras. This is also a good time to test and replace your heat lamps as needed, to have a warming area available for lambs in colder conditions.
Establish Proper Staffing Levels for Lambing
Lastly, lambing season usually requires a few extra sets of hands. Ensure that you have adequate staff levels, and plan for potential monitoring around the clock in the case of problem births. Also, ensure that all staff or helpers are well versed in the stages of parturition (dilation, delivery, and shedding of the placenta), and are able to recognize when a ewe may require a level of assistance that necessitates a call to your veterinarian. And remember that pregnant ewes typically give clear signs when they are close to lambing
How to Tell if a Ewe is Close to Lambing
- A few days before labor, the ewe’s vulva will swell and turn light pink to a darker pink (if she has light-colored skin).
- Closer to lambing, the ewe’s udder will feel tight and hard
- Ewes will typically separate themselves from the flock and limit or stop their feed intake; it’s important to spend extra time paying attention while feeding to notice these signs and finish any last-minute lambing preparations
Lambing season is an exciting time for producers, as it signifies the growing and continued success of your operation. And with proper planning and preparation, you can help to minimize the stress to your ewes, your staff, and yourself during this busy season. For more resources on risk management, livestock operation, and agricultural insurance products, visit Redd Summit’s blog and be sure to subscribe to stay up to date on new posts.