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A barn for rearing bull calves for beef production was divided into an open naturally ventilated part (O) and a closed-off part ventilated mechanically and with optional heating (C). Calves were kept individually (I) or in group pens (G) during the first 3 months. All calves were group-housed from 4–6 months of age. Growth rates (g/day) were respectively 671 (O), 656 (C), 677 (I), 650 (G) during the first 3 months and 991 (O) and 979 (C) during the second 3 months. However, arrears in growth were made good during the finishing period. There were no great differences in feed conversion and incidence of respiratory disorders. The mortality rates during the 6 months were 4.4% (O) and 6.3% (C). In both I and G there were 5.6% dead plus culled calves during the first 3 months. The incidence of respiratory disorders was 38.5% for I and 60.0% for G. The impact of tethering on preputial sucking was studied in the group-housed calves. Calves tethered for the first 2 weeks displayed no preputial sucking. It is concluded that calves for beef production can be reared in an open barn. Group-housing is attractive in terms of animal welfare, although it requires more farmer involvement.

Dairy cows can be fed concentrates in feeding stations with automatic feeding systems. This paper discusses factors which may influence the timing of the cows' visits to the feeding station. Factors affecting the dairy cows' behaviour just before and just after the visit, and information which might be used by the cows in deciding whether to visit the feeding station are investigated. An investigation was carried out with a group of 20 lactating dairy cows. In successive 3-week experimental periods the cows were fed concentrates with three different automatic concentrates feeding systems (fixed-7-time, fixed-3-time and variable-time systems). Twenty-four hour behavioural observations recorded the cows' general activities while the number and duration of visits to the feeding station and the intake of concentrates were recorded automatically. The three concentrates feeding systems each gave rise to a typical pattern of visits (total number of visits, and timing of rewarded and unrewarded visits). However, the pattern of general activities was not affected by the concentrates feeding system. The cows' general activities both before and after their visits to the feeding station were significantly affected by the time of the day. However, the cows' possible knowledge about their chances of receiving concentrates did not affect their general activities significantly. The results suggest that the cows fitted their visits to the concentrates feeding station into their normal daily routine. For instance, the cows did not often leave the cubicles solely to pay a visit to the feeding station. It was also not possible to show that the cows spent more time eating roughage after an unrewarded visit to the concentrates feeding station than after a rewarded visit. The cows could have learned the times of the day when concentrates were available and that at certain times they could also expect concentrates when another cow visited the feeding station and received concentrates. However, it was shown that the cows visited the concentrates feeding station throughout the 24-h period, which means that the timing of their visits was not affected by the time of day. The results suggested that, to some extent, the cows responded to information from the feeding station. Rewarded visits were more often and more consistently followed by a visit by another cow than were unrewarded visits. It is concluded that the cows: (i) did not respond to variation over the 24-h period in their chances of obtaining concentrates; (ii) did not always respond to information from the feeding station. The cows apparently chose a strategy of paying regular visits to the feeding station, because the cost for such visits is low and the reward is sufficiently high.

On Dutch commercial farms automatic systems for feeding concentrates in a feeding station are being used increasingly. Various systems have been developed, which differ in the timing and amount of concentrates made available to the cows over a 24-h period. Three types of a fixed-time system and one variable-time system are compared with a traditional system. The fixed-time systems provided a ration of concentrates every 12 h. The starting time of these 12-h cycles varied, hence the fixed-7-time system started at 07:00 and 19:00 h; the fixed-11-time system cycles started at 11:00 and 23:00 h; and the fixed-3-time system cycles started at 15:00 and 03:00 h. The variable-time system continuously added small amounts of concentrates to the available ration per cow throughout a 24-h cycle. The traditional system provided concentrates mixed with maize silage at the feeding rack. The aim of the investigation was to describe the pattern of intake of concentrates, and the possible consequences of the various feeding systems on the cows' general activities such as eating, standing and lying down. Three experiments were carried out, each with a group of 20 lactating dairy cows kept in a cubicle house with a single concentrates feeding station. In each of the experiments, feeding systems were tested during 3-week experimental periods. Behaviour was observed during three 24-h periods in each experimental period. It was found that each of the five feeding systems tested evoked a typical pattern of visits to the feeding station. The number, the duration and the timing of rewarded and unrewarded visits differed between the various systems. The cows adapted to each feeding system, eating all their rations of concentrates as soon as they were made available. Adaptation to the feeding system affected several of the general activities, in particular the time spent at the feeding rack and the time spent lying in the cubicles. With the fixed-11-time system, new feeding cycles started at times when many cows were lying down. Under these conditions the lowranking cows sometimes had to wait a long time before they could enter the station, which resulted in a reduced lying time for them.

Although there is much information available on social dominance in dairy cattle the concept is still regularly discussed. The results of four experiments with dairy cows, together with the relevant literature are used to discuss the influence of housing and management on social dominance. In total, seven groups of dairy cows kept in cubicle houses were studied. Stable dominance relationships appeared to exist, but in 41.1% of all pairs both members displaced each other. It is argued that the housing system (feeding rack and cubicles) and the management (crowding) greatly influence the occurrence of successful displacements by a subordinate cow (‘contradictory displacements’) and of other ‘aberrant’ interactions. The role of social dominance in the daily life of the dairy cow is discussed. The chances of a cow obtaining resources (e.g. food or a lying place) can only be predicted to a limited degree from her dominance value. Various ‘disturbing factors’ (e.g. aberrant interactions, triangular relationships, individual variation in frequency and ‘direction’ of interactions) affect such a prediction. These disturbing factors are the result of the housing and the management at the dairy farm. It is concluded that the described dominance value is the best available because possible alternatives are more difficult to obtain and no more useful.

For dairy cows, a large variation is observed in daily time spent lying down. Individual variations and differences connected with housing or management are known to affect the actual time spent lying. A series of experiments with dairy cows kept in cubicle houses was carried out. We investi-gated the consequences of some details of the cubicle house and of overcrowding on the time spent standing and lying in the cubicles. The aim of the experiments was to obtain information about the significance of cubicles for resting and for hiding. Four experiments were carried out with a total of seven different groups of dairy cows. In the first experiment, the cows were kept in a so-called old cubicle house, which differed in various ways from a so-called new cubicle house in which the other three experiments were performed. In each experiment, a normal situation — with as many feeding and lying places as animals in the group — was compared with an overcrowded situation in which both the number of feeding and lying places was reduced. In the four experiments, overcrowding levels of 50, 55, 25 and 33.3% were tested. To measure the time spent eating, standing and lying, detailed observations were carried out for 24-h periods. Under normal conditions, the cows spent ∼13 h lying and 2.5 h standing per 24 h. In the old cubicle house, under normal conditions, the time spent in the cubicles was lower than in the new cubicle house. This is probably due to two factors: (1) the cubicles were smaller and less comfortable; (2) in the old cubicle house the cows could hide from confrontations with group mates at the feeding rack with its separations between the feeding places as well as in the cubicles. Overcrowding resulted in a reduction in time spent lying in the cubicles and also in a reduced time spent standing in the cubicles in the new cubicle house. It is concluded that under over-crowded conditions, lying is more important than standing in the cubicles. Based on these experiments and on the available literature, it is concluded that lying is important for the cows. This means that cubicles are important for the cows; however the minimum time that the cows need to lie or stand in a cubicle is not yet known. Various factors are suggested which may affect how long the cows need to lie.

The influence of physical stress on the plasma concentration of the acute-phase proteins serum amyloid-A (SAA) and haptoglobin (Hp) was studied in 10 calves. Two different stress levels were created by housing two groups of five calves, each on different types of floor. The stress level was assessed by studying videotapes of the animals, and, subsequently, by quantifying the problems related with moving across the pens and the time the calves spent lying down and standing. Plasma concentrations of Hp, SAA, aldolase, and cortisol were measured in blood samples obtained by jugular venepuncture. Plasma SAA concentrations were significantly (p < 0.001) elevated in animals housed on the floor type associated with the highest level of physical stress, although the concentrations were within the normal range for healthy adult cattle. Hp concentrations were not elevated. The floor type did not alter the stress related biochemical variables aldolase and cortisol. It is concluded that plasma SAA concentrations rise upon physical stress, whereas Hp concentrations do not change. The absence of a significant difference in aldolase or cortisol concentrations indicates that the difference in the level of neuro-endocrine stress between the animals housed on the two floor types is only minimal. Consequently, SAA is suggested to be a sensitive variable to assess physical welfare in calves.

Automatic systems for the feeding and milking of dairy cows are being developed. Research is being carried out into the optimal development of these systems from the cow's point of view. Experiments have been performed where automatic systems for concentrate feeding serve as models for automatic feeding or milking systems. The influence of automatic systems on the daily rhythm and activity of the cows is being investigated. Both the pattern of concentrate distribution and the amount of concentrates delivered per visit can be varied by manipulating the computer program for the distribution of the concentrates. A preliminary analysis of the results of this experiment has revealed that cows respond immediately to those changes in the concentrate feeding system which affect their concentrate intake during the day. The cows took longer to adapt to changes in the feeding system affecting their intake during the night. Surprisingly, changes in the number of visits and in time spent in the concentrate feeding station did not influence the time spent lying or standing in the cubicles. The importance for the cows of understanding how the system functions was investigated by giving acoustic signals to individual cows. Five cows learned to visit the concentrate feeding station after receiving an acoustic signal. In later experiments, the order in which the five cows received their signal was changed and also the time of day at which the signals were transmitted; the cows responded satisfactorily under those circumstances. Behaviour of Cows in Completely Automated Feeding Systems J. METZ and A.H. IPEMA Institute of Agricultural Engineering, P.O. Box 43, 6700 AA Wageningen (The Netherlands)