The objective of this research was to determine the correlation of udder volume and nipple size with milk production of Holstein Friesian dairy cows at PT. Naksatra Kejora, Temanggung Regency, Central of Java. The research was conducted on October 1 to November 30, 2018 that used 35 lactation Holstein Friesian cattle with lactation period 1-5 and lactation months 1-10. The research method was carried out by observational method. The parameters measured were udder volume, nipple volume, nipple circumference, nipple length and milk production. Data were analyzed using correlation analysis, multiple and simple linier regressions, where the volume of udder and nipple size as independent variables (X) and milk production as dependent variable (Y). The results showed that there was a significant correlation between udder volume and milk production and there was no correlation between nipple volume, nipple length and nipple circumference with milk production. It can be concluced that udder volume was the most appropriate variable to predict milk production with equation of Y =3.375 + 0.166X (R 2 = 0.704) in morning milking.

This research was completed at PT. Naksatra Kejora, Temanggung Regency, Central Java Province, Indonesia using 31Holstein Friesian cows (lactation period I-V and lactation month 1-10). The observational method was used in this study. The parameters measured were teat dimensions (teat volume as X1, teat circumference as X2, and teat length as X3) as independent variable and milking efficiency (milking time duration / milk production as Y) as dependent variable. Data obtained were analyzed using correlation, then using linear multiple regression to predict the milking efficiency from teat dimensions. Analysis of variance was used to test the significance of model. The result showed that there was no significant relationship between milking efficiency with teat volume (R = 0.070), teat circumference (R = 0.226) and teat length (R = -0.090). The multiple regression model was Y = 1.141 + 0.003 X1+ 0.050X2- 0.092 X3 (R2 = 0.236, no significant P = 0.061). It was concluded that it was difficult to predict the milking efficiency from teat dimensions on Holstein Friesian cow in Temanggung Regency.