Hoof trimming resulted in compensatory growth of the hoof, reduction in heel bulb hardness and increasing size of middle part of the sole. A regular hoof trimming can make better weight bearing surfaces and earlier detection of the injuries that finally resulted in reduction of lameness in the herd. In phase one of this current study, information of hoof trimming based on trimming 100-120 days after parturition (Group I), immediately before drying (Group II), high locomotion score cows (Group III) and cows with long toes (Group IV), were recorded in 10 dairy farms in 5 provinces of Iran. In phase two 40 cows were selected in groups I, II and IV in one dairy farm. Toe length of the forelimbs in different digits was measured in selected cows immediately before trimming. All data reported descriptively and also compared in different groups using t-student test, and p values under 0.05 revealed as significant. In phase one, information of 9580 cows were collected. Total of 31933 trimming and checking for possible injuries were done during this period. The average of 3.33 times a year cows referred to trimming chute during this programme. In earlier studies 2, 3 and 3-4 times of annual hoof trimming was suggested to be done in a herd. In phase two the toe length in each group recorded as 85.5±7.1 mm in group I, 87.4 ±7.2 mm in group II, and 87.6 ± 5.9 mm in group IV. A significant difference recorded between group I and other groups (P<0.05) as the longest toe length recorded in group IV. Based on a minimum required toe length of 80 mm for supporting underlying tissues, 15.38, 7.8 and 2.5 percent of cows in groups I, II and IV respectively had toe length less than 80 mm. Results of study indicate that risk of over trimming is higher in group I. Keywords: Hoof trimming, Cow, Toe length, Timing.

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