01/10/2025
Lambing and kidding is right around the corner! This post does a fantastic job explaining selective deworming around the time of parturition. If you have questions regarding dewormer product selection please reach out to us!
Also, this Maryland Small Ruminant Extension page has great content, follow it to see more!
THE PERIPARTURIENT EGG RISE (PPER)
by Susan Schoenian
Sheep & Goat Specialist Emeritus
University of Maryland Extension
Though it’s winter, internal parasites should never be far from the minds of sheep/goat producers. In our Mid-Atlantic climate, we usually enjoy a “break” from worms, but spring will be here before too long, along with the resumption of worm life cycles.
The two groups of sheep/goats that are most susceptible to parasitic infections are lambs/kids less than six months of age and periparturient females. Lambs/kids are vulnerable for obvious reasons: their lack of immunity and lower volume of blood.
Though variable, sheep/goats develop immunity to parasites with age and exposure. However, ewes/does suffer a temporary reduction of naturally acquired immunity around the time of lambing/kidding. This is called the periparturient egg rise. (PPER) and it results in ewes/does having higher f***l egg (worm) and oocyst (coccidia) counts.
The magnitude of the PPER varies by species, breed, genetics, age, production stress, and season. The periparturient period usually starts about two weeks before parturition and extends for up to 8 weeks after. Thirty days is often the peak of egg counts. Some ewes/does may exhibit clinical signs of parasitism during this time, but mostly the higher counts become the primary source of parasitic infection for naïve lambs/kids.
In the past, it was recommended that all ewes/does be dewormed prior to lambing/kidding (or shortly thereafter). Due to the development of drug-resistant worms, this is no longer recommended. Instead, females should be selectively dewormed based on certain criteria.
Selective treatment includes deworming ewes with FAMACHA© scores of 4 or 5 and does with scores of 3 or higher. Thin ewes/does (those having body condition scores of 2 or less) should also be dewormed. Obviously, any ewe/doe with “bottle jaw” (or other clinical signs) should be treated. When selectively deworming, be sure to use an effective drug or (unmixed) combination of dewormers (from different chemical classes).
On the other hand, there is usually NO reason to deworm ewes/does in good body condition, with good FAMACHA© scores, especially those with singletons. Females nursing multiple offspring and/or producing more milk are under greater nutritional stress and may benefit from deworming. This includes mature ewes with 3 or more lambs, yearling ewes and does with 2 or more offspring, and high producing dairy females. Yearling (first-time) mothers are more susceptible to the PPER and are additional candidates for potential deworming.
Deworming isn’t the only strategy for countering the PPER. Research has shown that increasing the protein content of the late gestation ration (by about 30%) can reduce f***l egg counts. Protein sources with higher percentages of rumen bypass protein should be favored. Feeding BioWorma® during the periparturient period may help to reduce (re)infection of pastures with infective worm larvae.
The PPER is less pronounced in cooler and/or drier months. Lambing/kidding in the winter or fall can reduce the magnitude of the PPER and its influence on pasture contamination. Keeping animals confined (zero grazing) during the periparturient period will practically eliminate worm issues. Along with good hygiene, coccidia can usually be controlled by feeding a coccidiostat during late gestation. (and in the creep ration).
Long-term, the best strategy for controlling parasites in small ruminants is selecting more resistant breeding stock. It is especially important that flock/herd sires be low egg shedders and not require deworming, as they influence the genetics of far more offspring than females.
Originally published in the Delmarva Farmer
https://americanfarm.com/articles/delmarvafarmer/the-periparturient-egg-rise-shepherds-notebook-3/
