The main factors affecting somatic cell count in organic dairy farming

Preventive management practices are essential for maintaining acceptable udder health status, especially in organic fanning, in which the use of antimicrobials is restricted. The contribution of the following factors to somatic cell count (SCC) was assessed in 788 cows from 15 organically reared herds in northern Spain: milk production, lactation number, treatments applied, selective dry cow therapy and teat dipping routines. The data were examined by linear logistic regression. Lactation number was the main factor affecting logSCC (beta= 0.339, p<0.001) followed in order of importance by milk production (beta= -0.205, p<0.001), use of alternative treatments (beta=0.153, p<0.001), selective dry cow therapy (beta=0.120, p=0.005) and teat dipping routines (beta=-0.076, p=0.028). However, the model only explained 17.0% of the total variation in SCC. This variable depends on factors other than those considered here, amongst which udder infection is probably one of the most important. Nonetheless, the study findings enabled us to determine the contribution of the main management factors that should be taken into account to improve udder health status on organic farms.