Journal watch1 April 2026
Author(s): F.M. Lovatt, J.J. Powell, C.A.P. Bastos and I.S. McCrone
Published in: Veterinary Record
Date: December 2025
DOI: https://doi.org/10.1002/vetr.70169
Type of access: Open access (click for full article)
Our summary
The aim of this pseudorandomised controlled trial was to compare the effectiveness of 10% iodine in protecting navel and ear tag sites of neonatal lambs with the effectiveness of a navel barrier solution (NBS), comprising of biopolymer shellac plus low levels of zinc and iron ions that are dissolved in ethanol.
Ten farms with 11 flocks from across England and Wales were recruited for the study, which ran from December 2023 to April 2024.
The design of the study involved lambing personnel alternating between 10% iodine for lambs given odd-numbered ear tags and NBS for lambs given even-numbered ear tags, using the standard methods of application for both treatments. The two treatments being different colours prevented blinding. Data was collected according to usual flock procedures, and records were kept of joint ill and mortality rates, method of navel application, and weight at follow-up. However, due to mortality records and time of death not being accurately reported, absence at the follow-up weighing event was used as a sensitive and objective proxy for death.
A total of 6840 lambs participated in the study, with 3385 receiving the 10% iodine navel treatment and 3455 receiving the NBS navel treatment. The mortality rate for the NBS group was significantly lower at 6.51% (225/3455), while the mortality rate for the iodine group was 8.36% (283/3385). Within the iodine navel treatment group, 880 lambs received a variety of non-iodine ear tag treatments; in the subgroup that had iodine applied to both navel and ear tag sites, the mortality rate was further increased to 9.34%. Another significant finding was the difference between application methods, as lambs with navels that were treated by spraying had an mortality rate of 9.48% (276/2911), compared to the 5.42% (92/1698) mortality rate for navels that were treated by dipping only, and the 6.28% (140/2231) rate for navels that were sprayed then dipped 12 hours later.
Limitations of the study include the lack of true randomisation due to impracticality, as well as the impossibility of operator blinding. Another limitation involved the likelihood of joint ill and mortality rates not being faithfully reported. However, statistical analysis found the number of lambs missing at the follow-up weighing to be suitable as a sensitive and objective proxy for death.
The trial was approved by the Ethics and Welfare Committee of the Department of Veterinary Medicine of the University of Cambridge. The article discloses that NBS technology is owned by the University of Cambridge and licensed by NoBACZ Healthcare; two of the authors are inventors of the technology, with another providing consultancy services for NoBACZ Healthcare.
Take home
The study provides some evidence that NBS is more effective than 10% iodine at mortality in neonatal lambs. It also provides evidence that treating navels and ear tags by dipping as opposed to spraying is a superior application method.
The following may also be of interest
Journal watch: A cross-sectional survey of farmer reported prevalence and farm management practices associated with neonatal infectious arthritis (“joint ill”) in lambs, on UK sheep farms. [RCVS Knowledge] [Online] Available from: https://www.rcvsknowledge.org/resource/a-cross-sectional-survey-of-farmer-reported-prevalence-and-farm-management-practices-associated-with-neonatal-infectious-arthritis-joint-ill-in-lambs-on-uk-sheep-farms/ [Accessed 1 April 2026]
NoBACZ Navel [NoBACZ Healthcare] [Online] Available from: https://nobacz.com/product/nobacz-navel/ [Accessed 1 April 2026]
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