New label for Lincomix offers flexible dose rate for M. hyo
Michael Senn, DVM, recently talked with editors of Pig Health Today about the new flexible dosing claim for a popular feed medication and, more important, what it means to US pork producers and swine veterinarians battling mycoplasma in their herds.
Q: The feed medication Lincomix® (lincomycin hydrochloride) has been used for decades to reduce the severity of pneumonia in pigs caused by Mycoplasma hyopneumoniae (M. hyo). What’s new with the product?
MS: The product hasn’t changed, but its label has — most notably, the dose rate and indications for use.
Lincomix can now be used at the rate of 100 to 200 grams/ton for 21 days for reducing the severity of respiratory disease associated with M. hyo. Previously, the rate was 200 grams/ton for 21 days for reducing the severity of pneumonia caused by M. hyo.
Q: What’s the practical significance of the changes?
MS: Lincomix is still the only feed medication labelled for reducing the severity of M. hyo. The new label gives veterinarians more flexibility while reducing costs for producers if the lower dosage is appropriate for the problem at hand.
In addition, Lincomix is still approved for controlling ileitis due to Lawsonia intracellularis at 100 grams/ton for 3 weeks or until signs of ileitis disappear. Because the Lincomix dose rate for ileitis is now the same as the minimum dose rate for M. hyo, one product can be used to address two diseases when needed.
Q: Does the new Lincomix claim affect the withdrawal time?
MS: No. There is still a zero-day withdrawal period for Lincomix.
Q: The lower dosing option is a plus, but is it effective?
MS: Yes, it is. We recently conducted a study involving more than 1,600 pigs at eight US swine operations. From 28% to 76% of pigs on each site were positive for M. hyo.1
When Lincomix was fed at 100 grams/ton for 21 days, treated pigs had reduced lung lesions and coughing scores at 21 days compared to controls. The Lincomix groups also demonstrated better average daily gain, feed efficiency and final bodyweight compared to untreated controls. The differences were significant (p < 0.05). Treated pigs were nearly 4.2 pounds heavier than non-medicated control pigs at the end of the 21-day period (Figure 1).
Q: M. hyo has been around a long time. Why is it still a problem?
MS: It’s estimated M. hyo is present in more than 50% of US herds.2 It remains a top cause of pneumonia.3 It can occur in young pigs but usually affects finishing-age pigs, when producers have already made a considerable investment in those animals.
M. hyo is a tough organism to control because it targets the respiratory tract cilia and can persist for weeks. Some pigs don’t show signs of infection but can still infect other pigs. M. hyo not only causes poor feed conversion and growth, it increases susceptibility to other respiratory infections, and it is a component of porcine respiratory disease complex.
Q: What else can be done to improve M. hyo control?
MS: You need to take an integrated, holistic approach using other tools available in addition to in-feed medication use. Vaccination can help reduce M. hyo shedding in the nursery and potentially reduce vertical and horizontal M. hyo transmission.3 Some veterinarians advise administration of a long-acting injectable antimicrobial to young pigs. In addition, the introduction of replacement gilts must be carefully managed — and maintaining good biosecurity is imperative.
Q: How can Zoetis help producers achieve optimal results with Lincomix and compliance with veterinary feed directive (VFD) regulations?
MS: Through our STOMP® diagnostics program, we collect samples and have them tested at independent labs for M. hyo detection to validate the need for Lincomix. We help determine the best age for Lincomix administration. Our nutritionists can design feeding protocols that include Lincomix with each operation’s budget in mind. We can help train herd caregivers and feed-mill staff and conduct feed assays at our Customer Analytical Support Laboratory. Overall, our program is designed to ensure VFD compliance and reduce M. hyo’s economic impact.
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Caution: Federal law restricts medicated feed containing this veterinary feed directive (VFD) drug to use by or on the order of a licensed veterinarian.
1 Data on file, Study Report No. A121C-US-14-150, Zoetis Inc.
2 Thacker EL, Minion FC. Mycoplasmosis. In: Zimmerman JJ, Karriker LA, Schwartz KJ, et al, eds. Diseases of Swine, 10th ed. Oxford, UK: Wiley-Blackwell; 2012:779-797.
3 Galina L, et al. A Contemporary Review of Mycoplasma Hyopneumoniae Control Strategies. (2016).