Behaviour of Beef Bulls Reared Together With Lactating Cows and Calves on a Pasture/Meadow Complex

Abstract

The behaviour of two groups of two bulls, lactating cows and calves from the Hereford and Limousin breeds was studied in the artificial pasture/meadow complex "Boyadzhievo" owned by the Research Institute of Mountain Stockbreeding and Agriculture on the outskirts of the town of Troyan. The complex is situated at 610 m above sea level, on a flat terrain with traditional grass. The meteorological characteristics of the late spring were studied, behavioural reactions were studied: grazing, rest, movement and acts of aggression. Natural grassland, which is also the main source of food for the animals surveyed in the pasture complex, was rich in plant species, of which the largest share belonged to the group of forbs (55%), followed by the group of cereals (38%) and leguminous (7%) grasses. Atmospheric conditions and the botanical composition of the pasture had an influence on the ethological reactions of the studied animals. It was found that Index for functional activity (IFA) grazing of Hereford bulls was 0.45455 on pastures, cows – 0.46934 at the time of the experiment and those of the Limousin breed - 0.45448, cows 0.47846. The index of functional activity rest in bulls of both breeds on averages 0.50360 and cows 0.48144.The acts of aggression for the research period were comparatively short: for Hereford bulls and cows 40 and 35 minutes respectively, and for the Limousin breed – 39 and 35 min. The most prolonged acts of aggression were those to motor vehicles, cars passing through and birds, and less pronounced were those to humans, dogs and wild game (foxes).