On-farm storage of livestock vaccines may be a risk to vaccine efficacy: a study of the performance of on-farm refrigerators to maintain the correct storage temperature

摘要

Livestock vaccines (LV) are often stored on-farm, in a refrigerator (fridge), prior to use and little is documented about the storage conditions during this period. As the quality of a vaccine can be impaired by storage at an incorrect temperature, the present study aimed to evaluate the on-farm performance of farm fridges to maintain the correct storage temperature. From January to August 2014, temperature data loggers were placed on selected farm fridges used to store LV (n?=?20) in South-West England. Temperature recording data was available from 17 of the 20 farms. Fifty-nine percent of farm fridges had at least one temperature recording above 8?°C, 53% had at least one recording below 2?°C and 41% at or below 0?°C. Internal fridge temperatures attained 24?°C and dropped to ??12?°C as an absolute maximum and minimum respectively. Fridges tested spent an average of 16% of the total time recorded above 8?°C. Time of the year significantly influenced the percentage of time above 8?°C. External and internal temperatures were found to be positively correlated (p?