Relationship of Udder, Flank and Lower Leg Hygiene Scores with Elevated Somatic Cell Count and Prevalence of Subclinical Mastitis in Dairy Cow

Aim: To examine the association of udder, flank and lower leg hygiene scores with elevated somatic cell count (SCC) and risk of subclinical mastitis (SCM) in dairy cows in Nepal.

Study Design: Longitudinal.

Place and Duration of the Study: National Cow Research Program, Chitwan, Nepal; from September, 2019 to March, 2020.

Methodology: Eighty (Holstein Frisian, Jersey and Lulu) SCM-free cows were enrolled in the research and a single observer obtained the duplicate hygiene scores of said body parts on one (clean) to four (extremely dirty) scale. The individual SCC was analysed fortnightly and the data were transformed at log10 base. The effect of animal cleanliness on SCC and risks of SCM were statistically analysed using ANOVA by GLM (univariate); SPSS (version 25). Likewise, the association of hygiene score with SCC and risks of SCM were performed by Pearson’s correlation analysis and prevalence of SCM was assessed by Chi- square test.

Results: Mean hygiene scores were 2.39, 2.21 and 2.25 for udder, flank and lower legs, respectively. Majority of animals (UHS- 41.3%, FHS- 36.3% and LHS- 38.7%) had score 2 or 3 on all three body parts. The results showed a significant association (P<.001) between poor hygiene scores and increased SCC, with dirty udders, flanks, and lower legs linked (P<.001) with higher SCC and a greater incidence of SCM. Further, cleanliness in these areas significantly influences udder health, as evidenced by increased bacterial counts and SCM prevalence in cows with poor hygiene scores. These findings highlighted the importance of maintaining dairy animal hygiene to reduce the risk of SCM and to improve milk quality. Cleanliness of the udder and associated areas was vital for minimizing pathogen exposure. These findings also proved a strong correlation among poor hygiene scores and elevated SCC, which was associated with an increasing load of major bacteria (both contagious and environmental) and a higher prevalence of SCM.

Conclusion: Keeping dairy cows clean, especially around the udder, can significantly reduce the risk of SCM and ensure sound UH and milk quality. Further research is needed to optimize hygienic management for enhancing udder health in dairy cows.