Pseudorandomised controlled trial of a novel navel barrier solution versus 10% iodine to protect navel and ear tag sites of neonatal lambs

BACKGROUND: During lambing, 10% iodine is often used to protect neonatal navel and ear tag sites. The evidence for its effectiveness is sparse. Recently, a specific navel barrier solution (NBS) was developed. Here, an in vivo field trial compared the two treatments. METHODS: Ten farms reported data from 6840 lambs. The navel and ear tag sites of alternate lambs were treated with usual care-iodine or NBS. Usual care-iodine was 10% iodine for all navels and for most ear tag sites. RESULTS: Mortality was 8.36% for the usual care-iodine group and 9.34% for the sub-group where only iodine was used for navel and ear tag sites. It was 6.51% for NBS (p < 0.004 vs. iodine groups). Mixed-effect generalised linear modelling gave an adjusted odds ratio (OR) for mortality of 0.76 for NBS (95% confidence interval [CI]: 0.63-0.91; p = 0.003). Spraying navels was inferior to dipping them for survival (OR 2.14; 95% CI: 1.11-4.09; p = 0.02). Farmers did not report differences in joint ill between the groups. LIMITATIONS: For practical implementation, the study was non-blinded and pseudorandomised. Non-appearance of a lamb at the week 8 weighing event was taken as a sensitive and objective proxy for death. CONCLUSION: Optimal navel and ear tag site application during lambing efficiently protects against neonatal deaths. NBS is superior to 10% iodine, and dipping outperforms spraying for improvement of lamb survival.