Importance of herd management in loose housing systems in the social behavior of dairy cows

In five loose housed dairy herds three different kinds of herd management were tested in two variants with respect to frequencies of agonistic social behaviour. Treatments were (1) a short (0.5 h) and a long (3 h) fixation time in the feeding rack, (2) single and group (3 animals) introduction of new heifers into the herd and (3) an open and a closed outdoor yard during nighttime. The investigated agonistic behaviour patterns were: pushing and chasing. The herds were observed in the evening after milking during one four-hour period starting one hour after opening the feeding rack when testing treatment (3) and immediately after opening the feeding rack when testing treatment (1) and (2). Statistical analysis were carried out with the Wilcoxon signed-ranks test for matched samples. Effects of fixation time differed inconsistently and were not significant. In 3 out of 5 farms the frequency of agonistic behaviour was lower, when cows were restrained 3 h in the feeding rack compared to 0.5 h. In two of these 3 herds, the animals had the possibility to drink water from bowls directly at the feeding rack, in the third herd the food was silage which has a higher water content. Therefore in these herds, the agonistic interactions at the drinking facility in the stable after opening the feeding rack was low. Contrary, in the two other herds, with dry feed (hay) and no drinking bowls at the feeding rack, frequency of agonistic behaviour was higher after the long restraint which might be due to higher competition at the drinking facilities. Agonistic interactions per cow as well as per new introduced heifer were lower (p < or = 0.05) when only a single heifer was introduced to the herd compared to the introduction of a group of 3 heifers. The frequency of agonistic social behaviour of horned dairy cows that had access to a yard at night was significantly lower compared to the situation when the yard was closed over night (p < or = 0.05). This may be due to the higher space allowances per cow but also to the additional structuring of the locomotion area.