Relationship between teat-end hyperkeratosisat the beginning of dry period and new mammaryinfection rate in dairy cattle

Milk samples in an aseptic manner at the beginning of dry period and three days after parturition from 124 mammary quarters (37 cows) were collected to determine somatic cell count (SCC). All quarters were scored (1 to 5)on the basis of teat–end hyperkeratosis to establish a correlation between the score and new infection rate andSCCs. After the last milking, a commercial intramammary antibiotic was used for all quarters. In this study criticalvalue of 250000 cell/ml was set for SCCs. Samples with somatic cell count lower and greater than this critical valuewere considered healthy and infected respectively. The statistical analysis showed 26.5 % new infection rate and5% cure rate at 3 days after parturition. The score were 1, 2, 3 and greater than 3 for 40%, 36%, 21% and 3% ofevaluated teats respectively. There was signifcant difference between milk SCC at the beginning of the dry periodand SCC of three days after parturition (p=0.0005, r = 0.8) Statistical analysis also showed signifcant differencesbetween teat-end hyperkeratosis and SCC at the same periods (p=0.0005, r = 0.66).There was no signifcant differences between teat score and new infection rate (P>0.05).