The effect of post milking test dip and suckling on teat skin condition, bacterial colonisation, and udder health

The teat skin of cows was scored (1 : smooth as silk; 2: smooth; 3: slightl y rough; 4: rough; 5: cracked; and 6: sores) by trained technicians who mov ed their fingers down the barrel of the teat with a light touch. Technician s ranked the same population of teats in the same rank order, but their mea n values differed by half a score which probably could be related to the sk in condition of their own fingers. Half udder experiments were carried out for 6 months at 4 farms with 35 to 52 cows each. A postmilking teat spray w ith 10% glycerol improved teat skin condition (p<0.10) compared with no tea t spray. A postmilking teat spray with 120 ppm chlorine dioxide did not inf luence teat skin condition compared with no teat spray. No differences in u dder health could be proven between treatments. Control studies revealed th at 10% glycerol as an emollient of a postmilking teat spray improved teat s kin condition within 3 weeks from being slightly rough to being smooth for lactating cows (p<0.05) but not for dry cows having smooth teat skin. Neith er glycerol nor chlorine dioxide influenced absolute number of bacteria on teat skin after a challenge with Streptococcus uberis and Staphylococcus au reus but half life of S, aureus on unsprayed teats was longest (p = 0.05). Suckling made teat skin more rough than machine milking. Nevertheless, suck ling lowered the number of esculin positive bacteria on the teat skin. We c oncluded that the condition of healthy teat skin (scores 1-4) has no influe nce on bacterial colonisation in the absence of cracks and sores (scores 5- 6).