Abstract: In this study,a selected principal component evaluation model for the udder traits was established by analyzing the correlation between udder traits of different parities and the correlation between udder traits and lactation performance in Mediterranean buffaloe.The study was helpful to breed high-yielding buffalo with excellent udder characteristics.A total of 123 Mediterranean buffalo with 1 107 records were employed in this study,the correlation analysis was performed using SAS 9.2 CORR process,and the selected principal component evaluation model was established using PRINCOMP process.For 1-4 parities,the 270 d milk yield increased with the increasing parity.At 1 to 2 parities,the front teat length were extremely significantly positively correlated to the hind teat length (P<0.01).There was a significant positive correlation between the front teat length and the hind teat length at 3 parities and above (P<0.05).At 1 to 4 parities,the teat area was extremely significantly positively correlated with the front teat distance,front and hind teat distance,as well as hind teat distance (P<0.01).Additionally,the front teat distance was extremely significantly positively correlated with hind teat distance (P<0.01).At more than 4 parities,the front and hind teat distance was significantly positively related to the milk yield and milk protein (P<0.05),and extremely significantly positively related to the milk fat (P<0.01),at the same time,the area of the teat was significantly positively related to the lactation performance (P<0.05);At 1st to 2nd and 4th parities and above,there was a very significant positive correlation among milk production,milk protein and milk fat (P<0.01),and there was a significant positive correlation among lactation performance at 3rd parity (P<0.05).The selected principal component evaluation model was Y=0.2631x1+0.1186x2+0.0862x3+0.0796x4+0.1039x5+0.0042x6-6.9689,in formula,x1,Front teat length;x2,Hind teat length;x3,Front teat distance;x4,Front and hind teat distance;x5,Hind teat distance;x6,Teat area.This study further revealed that there was a strong correlation among udder traits in different parities of Mediterranean buffalo,and the correlation between teat length and lactation performance was affected by parities.

Key words: Mediterranean buffalo; udder traits; lactation performance; selected principle component; assessment model