Özet:

The effects of teat measurements and milk production on the onset of subclinical mastitis in dairy cows. The study was conducted on 287 cows. Most of the experimental animals were raised on five dairy farms but sone of the cows were the animals which were brought to the clinics of the Veterinary Faculty for the reasons of other than mammary problems. A total of 13 measurements were taken once from each of the lactating cows. Milk samples were taken from each of the teats for California Mastitis Test and the results were evaluted as pozitive or negative. A total of 157 cows were rated as CMT+ out of 287 animals. This result may indicate that subclinical mastitis (SCM) is wide spreed among the cows. The chi square tests revealed that the differences among the five dairy breeds for the incidence of the SCM were highly significant (P< 0.01). The highest CMT+ readings were found in the Brown (68 %) and the lowest in the crossbreed (17 %) genotype groups. This may be due to the heterosis effect in the crossbred group. No statistical difference was found between hand milked and machine kmilked cows. As the number of lactations were increased the rate of CMT + readings were also increased (P< 0.01). The avarages for the teat diameter, teat length and daily milk yield were higher for tine cows with CMT + then CMT - groups (P < 0.01). The distance from teat end to the ground was lower in the CMT+ group. The differences between upper and lower diameter of the teats were 0.40 cm in CMT+ and 0.30 cm in CMT - groups, indicating funnel shaped teats are more susceptible to subclinical mastitis. İt was concluded that the incidence of SCM is common among dairy cows in Ankara area. The increases in lactation number and milk yield make the mammary gland predisposed to the SCM. Periodical screaning tests should be performed for the detection and treatment of the subclinical mastitis in cows

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