Lambing season: Controlling losses can add profit
When dealing with significant lamb mortality, it is important for producers to identify why those losses are occurring, according to a North Dakota State University Sheep Specialist.
“Don’t stick your head in the sand,” Reid Redden cautioned producers during a recent webinar on lamb losses. “When lambs are dying, take a proactive approach, find out why those losses are occurring and develop a new preventive management system.”
In most operations, a loss of 10 to 20 percent of the lambs born is normal, but Redden said producers should always be looking for ways to save more lambs using less labor.
One of the biggest factors in lamb losses is birth weight. Twin and triplet born lambs also have a greater mortality rate than single-born lambs, he added. The larger the lambs are, the more likely the ewe will experience dystocia. With multiple lambs, they are more likely to become tangled up making it harder for the ewe to deliver them unassisted.
Once the lambs are born, Redden said producers need to make sure the lamb receives as much colostrum as possible within the first 12 hours of birth.
“There is no such thing as too much colostrum,” he explained.
The lamb isn’t born with all the antibodies it needs to fight off disease, so it is crucial that it receives colostrum within the first 12 hours of birth before the digestive tract can no longer absorb it.
Colostrum also contains fats and proteins to help the lamb get off to a good start.
Producers will also want to ensure the ewe is bonding with the lamb, so when they are turned out with the rest of the flock, the two stay together.
Redden said he likes to keep ewes and their newborn lambs in a lambing jug for one to two days after birth, so he can make sure they are pairing up. After that, he moves them to a small area with approximately 10 to 12 other ewes and lambs for a week, before turning them about with the rest of the flock.
Producers need to make sure their ewes have good genetics and a good maternal behavior score, Redden said.
“They should have good temperament and the ability to want to take care of their lambs,” he added.
Another cause of death in newborn lambs is pneumonia.
“There is no cure for a weak respiratory system in sheep,” Redden said.
When lambs and ewes are confined in a barn during cold winter months, belching and coughing from the ewes, plus the urine significantly reduce the air quality in the barn, he explained.
“It is important to get that contaminated air out to reduce the number of pneumonia cases in lambs,” Redden added.
Some research has been conducted creating a negative ventilation system in the lambing barn, which significantly helped reduce pneumonia cases, Redden shared.
When the lambs are born in the spring when it is warmer, they can be born in a bigger, more open barn and in areas where they are less confined.
“In this situation, it is not compromising the lamb’s respiratory system by putting them in an area where air quality is significantly compromised,” he said.
Other lamb diseases
Producers also have an important job of keeping lambing jugs clean to reduce the incidence of scours.
Between two to four days of age, lambs can contract scours from E. coli contamination if the lambing jugs aren’t kept clean of manure.
“It is really important to keep the jugs clean, especially between ewes and lambs,” Redden explained.
The Dubois station has done some research showing that adding chlorate salts to feed can reduce the E. coli population in sheep, but the salt isn’t approved for use in sheep at this time, Redden noted.
Other ways to prevent lamb mortality are preventing navel illness by clipping the cord two inches from the navel and treating it with iodine to kill bacteria and dry up the navel.
Lambs also need to receive vaccinations to prevent entertoxemia. Redden recommends giving the ewe an injection two weeks to one month prior to lambing. The lamb should also receive an injection at 10 to 12 weeks and six to eight months.
Lastly, Redden encouraged producers to stay on top of their parasite control program in ewes and lambs once they are turned out to grass. Ewes should be wormed after lambing, before and after going to grass and as needed during the grazing season, he said.
It can be normal to see two to three percent of the lambs born as stillbirths, commented North Dakota State University Sheep Specialist Reid Redden.
“If the number gets much higher than that, I would have a diagnostic test done to find out why,” the sheep specialist said.
Diseases like chlamydia, vibriosis and toxoplasmosis can all cause stillbirths, abortions and weak lambs.
“Chlamydia is caused by a pathogen that is transmitted through the placenta and birthing fluids,” Redden said. “Unexposed ewes, including ewe lambs, have a high rate of abortion around 20 to 30 percent, whereas previously exposed ewes have a much lower rate of abortion, around zero to five percent. A high rate of weak and unhealthy lambs can be a sign of chlamydia in a sheep flock.”
He continued, “We recommend that shepherds add feed-grade antibiotics to late-gestation diets to treat ewe flocks diagnosed with chlamydia. Vaccines also can improve resistance to the disease; however, they are not 100 percent effective and do not provide lasting immunity.”
Vibriosis is caused by bacteria transmitted through birthing fluid. Redden recommends feed-grade and injectable antibiotics to treat the disease during an outbreak and vaccinating the ewes annually prior to breeding and during mid-gestation.
Toxoplasmosis is typically spread through feed contaminated by cat feces or birthing fluids. Although no effective treatment is available, Coccidiostats can be added to the ewe’s diet during gestation to prevent the disease, he said.