• Evaluation of hydrated lime as a cubicle bedding material on the microbial count on teat skin and new intramammary infection

      Gleeson, David E (Teagasc (Agriculture and Food Development Authority), Ireland, 2013)
      In two experiments, the effect of applying hydrated lime as a cubicle bedding material on the microbial count on teat skin and new intramammary infection were evaluated. In experiment 1, dry dairy cows (n=60) were assigned to one of three cubicle bedding treatments for a 5 week period. The treatments applied were: Hydrated lime (HL), HL (50%) + Ground limestone (50%) (HL/GL) and GL. In experiment 2, two teat disinfectants products chlorhexidine (CH) and iodine (I) were applied to teats at milking in conjunction with two cubicle bedding materials with lactating cows (n=60) for a sixweek period. The treatments applied were: HLCH; HLI; and GLI. The HL treatment had significantly more teats (P<0.001) with no Staphylococcus spp. or Streptococcus spp. bacteria present compared to GL. There were no differences observed between treatments for California Mastitis Test (CMT) score at calving or somatic cell count (SCC) post-calving. In experiment two, the HLI treatment tended (P<0.08) to have lower bulk milk SCC than the GLI. The average bulk milk SCC over the trial period was 68,000, 54,000 and 83,000 cells/mL for HLI, HLCH and GLI, respectively. The incidences of medium-term teat changes were numerically higher with HLI and there were no differences in the mean hyperkeratosis score between treatments. The mean teat hyperkeratosis scores on day 42 were 2.2, 2.1 and 2.1 for HLI, HLCH and GLI, respectively. The HLI treatment had lower levels of Staphylococcal and Streptococcal bacteria on teats compared to GLI (P<0.001). Hydrated lime could be successfully used as cubicle bedding material for dairy cows if used at the recommended rates with either chlorhexidine or iodine based teat disinfectants.