WATCHING OVER EWE: Helpful tips to combat death loss in sheep
April 16, 2015
There's an old adage that gets trotted out from time to time, especially in the spring: "lambs are born just looking for a place to die." This statement is less true now than in previous generations, however, shepherds looking to decrease death loss may find there are still some tips worth investigating as they supervise flock health.
A major reason for sheep's reputation of fragility, according to Dave Ollila, sheep field specialist from SDSU Extension, is the comparison to cattle. "Apply the management of cattle to sheep and you will be disappointed," he says. "Sheep are very respondent to good management — much more so than cattle." The more time and resources a producer commits to his flock, the better the results. It's all about expectations, he says. "If you buy sheep cheap, use them to follow cattle, and don't do much else, you will lose a lot more. That's low input managing, but it can still be profitable on a good lamb producing year."
Max Matthews, current president of the South Dakota Sheep Growers Association, and lifelong sheep operator, as well as a sheep shearer for over twenty years, agrees, "Every producer knows his limitations. The key to managing a flock is deciding what those limitations are [in terms of] time and money, and making management decisions from there."
If an operator is looking for new strategies to decrease death loss, both men agree a good place to start is supplemental feed. Making sure the ewes are getting optimal nutrition all the way from breeding to weaning can vastly influence outcomes — in fact, it may be the single greatest way to increase yield. Matthews says, "There is a saying, 'a pound of corn a day can work wonders,' and I have found that to be true." Because 70 percent of a lamb's pre-birth growth takes place in the last 45 days of gestation, it is especially essential to provide adequate caloric intake during this time. Depending on the grain and hay prices, the cost of producing a better conditioned ewe (and subsequently a healthier lamb with a significantly higher survival rate) is offset by the increased profit when the lambs go to market in the fall.
The "Flushing Effect" is another benefit of more intensively managed nutrition. By upping the caloric intake of ewes in the two weeks before breeding, producers prime the ewe to make more eggs, thus resulting in a higher lamb yield. A common mistake with this technique, however, is to stop too soon. Ollila says, "The higher level of nutrition must be maintained into breeding season to prevent the ewes' bodies from sloughing off the additional embryos." This means continuing to provide as much as 25 percent more feed in the 30-45 days following the introduction of the ram.
Choosing an appropriate time and place for lambing is another major variable in flock health. Confinement lambing has many benefits, and usually results in better outcomes than pasture lambing. However, it is only an option for those who have the facilities to do so, and does have drawbacks. Namely, it encourages the spread of disease, as ewes and lambs are kept in close quarters and moved through the jugs. It also requires significant monitoring and is very labor intensive for the operator.
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If confinement lambing is not an option, or is not desirable, Ollila suggests separating ewes into smaller bunches and making sure to provide plenty of cover in the pastures where they will lamb. Then he says, "Stay away!" Unlike cattle, it is better not to check if you can help it. Intervention usually results in a panicked ewe, and can easily cause mother and lamb to become separated.
Thankfully, not all management decisions have to be resource intensive. Matthews has seen a significant decrease in death loss from making one change: not letting the ewes get old. Matthews says culling at a designated age, whether they look good or not, has significantly impacted his flock's overall health. "Used to be we'd keep older ewes if they look good in the fall. Well, those were the ones we'd find dead in the lot come winter." In addition to saving winter feed costs, selling in the fall while the ewe is in good condition results in extra cash flow.
Pasture management is another factor to keep an eye on, especially in the spring. The presence of toxic plants such as death camas and cockleburs can kill sheep quickly, and there is no treatment once the plant is ingested. According to Dr. Sandra Holcomb, DVM with the Metzger Holcomb Animal Clinic in Spearfish, a sheep suffering from poisoning will demonstrate neurological signs such as staggering, walking strangely, or simply laying down. Regularly monitoring the pasture for these deadly plants, and expunging them before they have a chance to spread, is the key to preventing death loss from toxicity. Checking along drainage ditches, creeks, or dams, is a good place to start if you suspect a toxic plant infestation.
Holcomb also warns against the dangers of pregnancy toxemia. This metabolic disease stems from drastic dietary changes, and is often seen during times of stress, because it results from a drop in blood sugar. In pregnant ewes, Holcomb recommends close monitoring of feed around events such as shipping or shearing. "Don't lock them off of feed for more than a few hours, especially if it is hot," she says.
Finally, there is another old adage to keep in mind while making management decisions: "an ounce of prevention is worth a pound of cure." Deworming and vaccination regimes are two way to stave off disease and decrease lamb mortality. Ollila and Holcomb both strongly recommend regular deworming — if possible, deworming should be done as often as four times a year. Vaccination recommendations vary. Ollila suggests all ewes be given overeating shots two weeks before lambing so they can pass on immunity to their lambs. Holcomb adds that the overeating vaccine is available with the tetanus vaccine included, and recommends this addition for all lambs. She also suggests vaccinating all lambs against sore mouth. "The symptoms of sore mouth usually show up right around the time you want to take them to market, so it can significantly impact your bottom line." She adds, "If you've seen it before, you'll see it again, and it is very contagious." She also strongly recommends that in cases of large death loss, a vet be consulted immediately to determine the cause, so, if need be, a specific vaccination program can be started.