INFLUENCE OF AGE, GENDER AND SIRE LINE ON YOUNG CATTLE BEHAVIOUR TRAITS

The aim of this study was to test effects of age, gender, and sire line on dairy cattle behaviour. We have analyzed results of ethological tests for 40 Holstein breed animals (23 males and 17 females), offsprings of three sires. Maintenance behaviour were observed at the age of 90, 130 and 170 days. Behaviour in the maze was conducted at the age of 119 days, an open-field test was applied at the age of 124, 168, and 355 days. The social behaviour was determined by feeding on 155th day of the age. The times and the number of periods in all activities of maintenance behaviour were changing significantly (P<0.001) according to the age. The total time of lying, lying with ruminating, ruminating, feeding was increasing from the age of 90 days to the age of 170 days, on the other hand the time of standing was decreasing. The times of total lying, lying with ruminating, total ruminating, feeding were increased, and time of standing was decreased from the age of 90 days to the age of 170 days. Calves spent more time lying on the left side than on the right side. The number of ruminating periods was increasing according to the age. Eating periods were decreasing from the age of 90 to 170 days. The most of lying periods were recorded at the age of 130 days. The differences between sex were found in total time of lying, lying on the right side (P<0.05), and the males rest longer and had more periods of lying than females. We have found differences in times of feeding (P<0.001), total lying, standing (P<0.01), and lying on the left side (P<0.05) according to sire by comparing behaviour of the calves. Sire genotypes were significantly manifested in period number of total lying (P<0.001), lying on the right side, feeding (P<0.01), and standing (P<0.05). Males stood in the first part of maze longer than females (P<0.001), also length of total standing was longer by bulls (P<0.01). Heifers took shorter time to leave the maze than bulls (P<0.05). Sire lineages significantly differed in times of standing in the first part of maze and maze leaving. We did not find any significant differences either among sire lineage groups or between genders in locomotor behaviour measured by the number of crossed squares in open-field test. During all observations were more mobile heifers. No significant differences were found between males and females in social behaviour. The sire line influenced only the number of total duels (P<0.001). We found significant positive relationship between live body weight and time of staying in the first part of maze (r=0.3957**), time of maze leaving (