Erfassung der Futteraufnahme im Rahmen der Stationsprüfung potentieller Besamungsbullen

Abstract. Title ofthe paper: Recording of feed intake in stationary testing of potential AI bulls
This study was performed in order to estimate correlations between feed intake, eating time and daily gain in young bulls and in order to estimate genetic parameters for feed intake in successive testing periods aiming at reduction of costs for testing. Data were collected from 269 Station tested potential AI bulls of German Holstein. In the testing period beginning with the 112th and ending with the 312 day of life, bulls consumed 5.1 kg roughage in 125 minutes per day and increased their weight by 1,300 g daily. The heritability of feed intake was 0.42, of eating behaviour 0.40 and of daily gain 0.62. Between feed intake and eating behaviour no relationship could be observed. Hence, an indirect measurement of feed intake is not possible. The high genetic correlation between feed intake and daily gain of 0.96 is no reason to replace feed intake recording because of a promising relationship between feed intake and health of dairy cows. Because of a delayed Start of 32 % of all tested bulls a shortening of the test period should be orientated to the last testing periods. In the last testing period, the heritability of feed intake was 0.65 and the genetic correlation between feed intake in the last and in the whole test period was high with 0.88. Hence, the test period could be shortened favouring intake measurements between 263rd and 312th day of life.