Evaluation of tri-plate rapid on-farm culture system to make therapeutic decisions for mastitis cases in dairy cattle
Article excerpt
by Sajjad Ahmed, Jawaria Ali Khan, Muhammad Avais, Muhammad Imran Rashid, Muhammad Asad Ali The empirical use of antibiotics for clinical mastitis is a principal driver of antimicrobial resistance in dairy farming. While on-farm culture systems represent a promising strategy…
by Sajjad Ahmed, Jawaria Ali Khan, Muhammad Avais, Muhammad Imran Rashid, Muhammad Asad Ali
The empirical use of antibiotics for clinical mastitis is a principal driver of antimicrobial resistance in dairy farming. While on-farm culture systems represent a promising strategy for targeted therapy, robust evidence of their efficacy in heterogeneous commercial settings is still needed. We conducted a randomized controlled trial across 16 commercial dairy farms. Cows with clinical mastitis (CM) were allocated to a Positive Control Treatment (PCT) group (n = 57), receiving immediate empirical intramammary (IMM) antibiotics, or a Culture Based Group (CBG) (n = 46), where treatment was directed by a tri-plate on-farm culture system after 24-hour incubation. The cows were considered experimental unit with mixed-effect models within cluster correlation. Data was statistically analyzed using chi square tests, paired t-tests and Kaplan Meier survival analysis via SPSS (version 20.0). The culture-guided protocol enabled a reduction in antibiotic use, eliminating treatment for the 45.6% of CBG cases (no bacterial growth or Gram-negative infections). The clinical cure rates between the groups (CBG 82.6% vs. PCT 75.4%) were not statistically significant (p = 0.28). Similarly, bacteriological cure rates were comparable between (PCT 71.9% vs. CBG 71.7%, p = 0.987). However, the CBG approach revealed significantly lower treatment failure rate (17.3% vs. 24.5%, p < 0.001) with a shorter median time to clinical cure (3 days vs. 7 days, p < 0.001). At the herd level, the strategy was associated with a significant increase in milk yield (+6.94 L/day, p < 0.001) and reduction in somatic cell count (−56.8%, p < 0.001). The tri-plate on-farm culture system is an effective antimicrobial stewardship tool, facilitating a substantial reduction in antibiotic use while accelerating clinical recovery and improving udder health in commercial dairy operations.