In the present study, we tried to investigate if farm mates affiliate with each other and if the number of farm mates influences social and maintenance behaviours of cows in
communal pastures.
2. Materials and methods
2.1. ObserÕation sites Ž
. Two herds of cows were observed in the Onikoube communal pasture 38
8N, 1408E Ž
. and the Nanashigure communal pasture 40
8N, 1418E at 300–500 m and 550 m altitudes, respectively, in northeastern Japan. Both pastures consisted of artificial
Ž .
grasslands and woodlands. Orchard grass Dactylis glomerata L. and broad-leaved
Ž .
trees maple Acer spp. and oak Quercus spp. dominated in artificial grasslands and woodlands, respectively. The Onikoube pasture and the Nanashigure pasture were
divided into 10 paddocks of 59.3 ha and eight paddocks of 69.6 ha, respectively. Cows in the Onikoube pasture were observed in a paddock consisting of artificial grasslands of
6.8 ha and woodlands of 0.2 ha, and in the Nanashigure pasture in a paddock consisting of artificial grasslands of 10.3 ha and woodlands of 0.6 ha. There were two watering
places and some mineral blocks were supplied for cows in each paddock. The paddock in the Onikoube pasture was flat while the paddock in the Nanashigure pasture was
hilly.
2.2. Animals Ž
. A total of 80 Japanese Black heifers and cows 1–17-years-old mean s 7.5-years-old
from 38 farms were turned out into the Onikoube pasture at the same time without their Ž
. calves from 11 May to 12 October in 1995 Table 1 . Fifteen cows 3–5-years-old were
selected as focal animals from the Onikoube herd: five cows from five farms which turned out one cow each, five cows from three farms which turned out two cows each,
Table 1 The number of farms which turned out cows and the number of cows from each farm into the Onikoube
pasture and the Nanashigure pasture during observation periods Number of cows derived from each farm
Total 1
2 3
4 5
6 7
17 The Onikoube pasture
No. of farms 19
8 4
4 2
– 1
– 38
No. of cows 19
16 12
16 10
– 7
– 80
The Nanashigure pasture No. of farms
9 14
4 8
4 –
– 1
40 No. of cows
9 28
12 32
20 –
– 17
118
four cows from three farms which turned out four cows each, and one cow from one farm which turned out five cows. One hundred and eighteen Japanese Black heifers and
Ž .
cows 1–20-years-old mean s 6.6-years-old from 40 farms were turned out into the Nanashigure pasture at the same time without their calves from 12 May to 6 November
Ž .
in 1997 Table 1 . Twelve cows 3–8-years-old were selected as focal animals from the Nanashigure herd: four cows from four farms which turned out two cows each, two
cows from one farm which turned out three cows, one cow from one farm which turned out four cows, one cow from one farm which turned out five cows, and four cows from
one farm which turned out 17 cows. Only three yearling heifers had not experienced any grazing and the remainder had experienced previous grazing in the Onikoube pasture.
About one-third of the cows, including all focal animals, had experienced previous grazing in the Nanashigure pasture.
There were no differences among farms in rearing methods during the non-grazing period. Cows were kept in single pens or tied in stalls. They were sometimes released
into the arena as a group in each farm in good weather during the non-grazing period.
2.3. ObserÕation The two herds were observed for 5 days from 26 to 30 July 1995 in the Onikoube
pasture and for 4 days from 12 to 15 July 1997 in the Nanashigure pasture. The weather varied between fair, cloudy, and foggy and average temperatures at 8:00 were 27.5
8C in the Onikoube pasture and 22.9
8C in the Nanashigure pasture during the observation periods.
The three observers simultaneously followed three focal cows on each observation Ž
day, respectively 15 focal cows in 1995 s 3 observers = 5 days; 12 focal cows in .
Ž 1997 s 3 observers = 4 days . Each focal cow was observed for 8 h from sunrise 4:30
. in 1995 and 4:00 in 1997 on one of the observation days. The ethogram used for
recording is shown in Table 2. Ž
. The nearest neighbour’s number, her posture standing, recumbency, and walking
and the distance to the nearest neighbour as multiples of the cow’s body length were recorded at 10-min intervals in principle. These items, however, were not checked
repeatedly if the nearest neighbour relationship with the focal animal did not change: Ž
animals, the spatial relationship, and posture. Posture standing, recumbency, and
Table 2 The ethogram used for recording
Behaviour categories Behaviour types
Grazing Ingestive
Stand resting, stand rumination Rest
Recumbency resting, recumbency rumination Walking
Move Head throw, head butt, fight, escape
Agonistic Allogrooming, rubbing, physical contact
Affiliative
. Ž
. walking and maintenance behaviour grazing, resting, and rumination of the focal cow
were recorded at 1-min intervals. Social behaviour was observed continuously. The Ž
number of occurrences of agonistic head throw, head butt, fight and escape from .
Ž .
aggression and affiliative behaviours rubbing and physical contact , except allogroom- ing, and the time spent allogrooming were recorded. The performers and receivers of
social behaviour were identified.
2.4. Statistical analysis Whether focal animals chose farm mates as the nearest neighbours and allogroomed
with them was analysed using the binominal test. The data on the frequenciesrcowrhour of agonistic and affiliative behaviours except
Ž . allogrooming and the total duration s rcowrhour of allogrooming were a skewed
distribution. This data was subjected to square root transformation after an addition of Ž
. 0.5 and then analysed statistically Martin and Bateson, 1986 . The mean distance to the
nearest neighbour, the frequency of social behaviour and the mean duration of mainte- nance behaviour were analysed using a one-way analysis of variance to examine the
effect of the number of farm mates on these items. Data on focal animals, which were turned out with two to four farm mates, were pooled because the sample size was small.
Ž .
If the effect was significant, Fisher’s protected least significance difference test PLSD was used among cows having no farm mate, one, two to four, and 16 farm mates.
As there was no difference in behavioural data between the two herds, the data from them were pooled. The data on one focal animal in oestrus, which was turned out with
16 farm mates, were excluded from the analysis.
3. Results
