LIETUVOJE VEISIAMŲ JUODMARGIŲ GALVIJŲ SERVIS PERIODO TRUKMĖS IR JĄ VEIKIANČIŲ FAKTORIŲ ANALIZĖ.

Objective of the study was to performe analysis of days open in Black and White breed cattle population in Lithuania and to estimate factors influencing the days' open. Influence of breed, line, age at the first calving and lactation, and influence of days open on cows' productivity was tested. Statistical analysis was done using data on reproduction traits from 2001-2003 year. The highest influence on days open had breed of cows (1.1%, P<0.001). It was estimated, that with increment of lactation the days open have tendency to decrease. The influence of lactation on number of days open explains 0.4% of variation (P<0.001). Other factors explains 0.2% (P<0.001) of each parameter variation. There is positive correlation (0.16) between days open at the first lactation and days open at the other lactations' (P<0.001). The largest productivity was shown by cows with days open more than 150 days. [ABSTRACT FROM AUTHOR]