- Email: [email protected]
Social licking pattern and its relationships to social dominance and live weight gain in weaned calves
Applied Animal BehaviourScience, 12 (1984) 26--32
25
Elsevier Science Publishers B.V., ~ m . t e r d a m - - Printed in The Netherlands
SOCIAL LICKING PATTERN AND ITS RELATIONSHIPS TO SOCIAL DOMINANCE AND LIVE WEIGHT GAIN IN WEANED CALVES
SYUSUKE SATO
Department of Animal Science, Faculty of Agriculture, Miyazaki University, Miyazaki 880 (Japan) (Accepted for publication 23 February 1983)
ABSTRACT Sato, S., 1984. Social licking pattern and its relationships to social dominance and live weight gain in weaned calves. Appl. Anita. Behav. Sci., 12: 25--32. Social licking patterns of heifer and steer herds were observed and recorded during periods of resting and intermittent feeding. The results revealed the following features: (1) heifers and steers had 15.0 and 15.2 social licking interactions per hour which lasted for 37.8 and 41.0 s on average, respectively. The average time an animal spent licking was about 25 s per hour; (2) all the animals in the herds were licked by others, but only 72.3% o f the animals licked other animals; (3) the animals close in the social hierarchy tended to lick each other for a longer time than did remote animals; (4) the time receiving licking and weight gain tended to be positively correlated. The observations suggest that (1) the motivation o f giving licking may be individual-specific and may be influenced b y genetic factors, while that of receiving licking appears to be general, a n d that (2) social licking may mean not only cleaning the skin and hair o f a passive partner, but also leading it to psychological stability.
INTRODUCTION
In the field of cattle management, appeasing relationships have been less emphasized than hostile relationships such as social dominance. Sambraus (1969) and Wood (1975, 1977) suggested that social licking can be used as an index of affiliative relationship between two cows. In addition, Wood (1975) reported that "grooming is important as a behaviour leading to social stability within a herd". If the above ideas on social licking are supported, the weight gain of growing cattle may be positively correlated with social licking. From this point of view, the present study was designed to obtain some fundamental information about social licking patterns and the relationships of social licking to social dominance and weight gain of growing cattle.
0168-1591/84/$03.00
© 1984 Elsevier Science Publishers B.V.
26
MATERIALS AND METHODS Observations were made Qn 2 herds of weaned steer and heifer calves kept in adjacent pen barns during the first winter after weaning.
Animals and management The calves used in this study were born at the Kawatabi Farm of T o h o k u University from February to May in 1978. The animals were de-homed prior to weaning, and the male calves were castrated at about 5 months of age. The calves were weaned at around the middle of December 1978, and were allocated to one of t w o pen barns b y sex. Figure 1 shows the outline of the adjacent pen barns used. The barns had 1.3-m high fences, and the floors were covered with rice straw. The weaned calves were fed concentrates (2-2.5 kg/head/day), silage (5 kg/head/day) and hay (4--5 kg/head/day) twice a day at 9.00 a.m. and 3.00 p.m. Rice straw and water were provided ad libitum.
t
FEED TROUGH
HEIFERS
WATER
P
T
TROUGH
k\\\\\
FEED TROUGH
l
STEERS
N
I
__
16 8
JAPANESE BLAC
10
JAPANESESHOR HORN
11
SHORTHORN x BACK
<
9M
~<
Fig. 1. Plan of pen barns for raising cattle.
--
2
9M
>
J
l
OBSERVATORY (3M IN HEIGHT)
The herd of steer calves consisted of 10 Japanese Blacks, 11 Japanese Shorthorns and 2 crossbreds (Japanese Shorthorn X Japanese Blacks), while the herd of heifer calves consisted of 16 Japanese Blacks and 8 Japanese Shorthorns. The calves were half-sibs of each other within a breed. Freezebranding, ear-tagging and neck-tagging were done so that all the animals could be identified clearly from all directions.
Observations (1) Social licking. Observations of social licking patterns of calves were
27 carried o u t for the duration o f resting or intermittent feeding, when social licking is often observed. An observer stood on an observatory, 3 m high, at the south-east corner of the pen barns, and checked the behaviour of the animals using binoculars. The heifer herd was observed for a total 18.5 h from 17 January to 1 February, and the steer herd was observed for a total 10.5 h from 27 February to 6 March. The animals seen giving and/or receiving social licking were identified, and the time spent licking the b o d y surfaces was recorded with a stopwatch. Vulva-, penis- and udder-licking were excluded from the data. (2) Social dominance. The dominance relationships in the herds of heifer and steer calves were observed from 16 January to 15 February and from 27 February to 30 March 1979, respectively. All clear indications of social dominance were recorded when both dominant and subordinate animals were identified. The animals in heat and the animals which showed mere displacements at the feed and water troughs were omitted. The rank orders of animals in the herds were detemrined by the proportion of dominance behaviour the animal showed. (3) Weight gain. The calves were weighed on 18 December 1978 and 11 April 1979. Since the weight gain, which was taken as the difference between these 2 live weights, differed markedly by breed and sex, it was converted to a ratio o f the individual's weight gain to the mean weight gain by breed and sex. RESULTS AND DISCUSSION The results of social licking patterns of the calves are summarised in Table I. Fifteen and 15.2 incidents of social licking interactions per hour were obTABLE I Summary of data Herd of heifers No. of animals 24 Total observation time (h) 18.5 Licking interactions (times/h) 15.0 Time spent licking (s/h) 566.3 (s/interaction) 37.8 Time an animal spent giving licking (%)1
Range
0--3.826
Mean 0.655 Time an animal spent receiving licking (%)1
Herd of steers
23 10.5 15.2
625.3 41.0
0--6.362 0.755
Range
0.011--1.428
0.093--2.468
Mean
0.655
0.755
i Time spent licking Total observation time
x 10o.
28
served in herds of heifers and steers, respectively. The interactions lasted for 37.8 s and 41.0 s on average, respectively, during the observation time. The average times an animal spent in social licking were 23.6 and 27.2 s per hour in the herds of heifers and steers, respectively. Wood (1977) reported that the average time an animal spent in social licking in 2 monozygotic-twin herds of 104 cows and 40 heifers was about 7.5 s per hour. The areas available to these herds ranged from 0.77 to 1.42 ha. Sato et al. (1982, unpublished data) observed average licking times of 2.04 s per hour for a dairy herd of 61 animals in an area of 0.135 ha, and 45.21 and 35.88 s per hour for herds of 6 feeder calves of 4 and 6 months of age in pens of 37 m ~, respectively. These data indicate that age and density, as well as friendliness, may influence the time spent in social licking. It is noticeable that individual difference in time spent licking is greater than that in time spent receiving licking. Five heifers and 8 steers never licked any other calves, while all the calves were licked by other calves. The difference between the range (0--3.826% in heifers and 0--6.362% in steers) of time an animal spent licking and that (0.011--1.428% in heifers and 0.093--2.468% in steers) spent receiving licking may reflect the difference between the motivations of the licker and the lickee. As Sambraus (1969) pointed out, the motivation of the active partner may be to the specific individual, while that of the passive partner appears to be general and clear-cut (e.g. irritating stimuli). The time an animal spent licking did not differ by sex, but differed significantly by breed (P < 0.05). The time an animal spent receiving licking did not differ by sex or breed. ×2 tests for the numbers of licking partners (Table II) show that Japanese Black calves gave significantly more licking interactions than Japanese Shorthorn calves (P < 0.01). It is u n k n o w n whether this tendency was contributed by breed or by sire, because all the animals were
TABLE II ×2 tests for the numbers of animals socially licked by Japanese Shorthorns and Japanese Blacks Breed'
Observed number
Expected number
x2-value
Heifers JS JB
21 93
38.0 76.0
11.41"*
Steers JS JB
9 49
30.4 27.6
31.66"*
' JS ffi Japanese Shorthorn; JB = Japanese Black. **P < 0.01.
29
half-sibs of each other within a breed. In any case, the genetic factors appear to influence the motivation of licking animals. In order to ascertain whether the animal giving social licking t o o k the breed of its licking partners into account, the licking partners were grouped according to breed. The observed numbers of licking partners were compared to the expected numbers (Table III), and the average licking times per licking pair were compared between the 2 groups (Table IV). Tables III and IV show that Japanese Blacks tended to lick their own breeds more than the other breeds, while Japanese Shorthorns did not express preference for their own breed. The Japanese Shorthorns at the Kawatabi Farm of Tohoku University have been considered to be socially independent of neighbours, because of weak following-behaviour and a dispersive tendency during grazing (Sato et al., 1976a,b). This socially independent disposition of Japanese Shorthorns may be attributed to fewer licking interactions and the preference for a licking partner regardless o f breed.
TABLE III ×2 tests for the numbers of animals that socially licked the Japanese Shorthorns and the Japanese Blacks
Breed1 Licker
Observed
Expected
number
number
x 2.value
Lickee
Heifers
JS JS
JS JB
7 14
6.4 14.6
0.081
JB JB
JS JB
27 66
32.3 60.7
1.332 (P < 0.25)
Steers JS
JS
5
4.5
JS
JB
4
4.5
JB JB
JS JB
22 27
27.0 22.1
0.111 2.012 (P 0.175)
JS = Japanese Shorthorn; JB = Japanese Black. Table V shows the mean licking time per licking pair, with special reference to social order. Although the dominants tended to select subordinates as licking partners when giving licking, they did n o t always spend more time in licking subordinates than the subordinates did in licking the dominants. As the animals used in this study were immature and had been reared together since birth, their dominance relationships were not established completely and bidirectiolially. Therefore, the dominance relationship may be very loosely related with the social licking relationship.
30 TABLE IV Breed comparison between times (s/licking pair) spent licking Breed I
Time x (s/licking pair)
Licker
Lickee
Heifers JS JS
JS JB
28.43 ± 36.88 (7) 38.57 ± 41.08 (14)
JB JB
JS JB
94.52 ± 112.67 (27) 108.86 ± 143.88 (66)
Steers JS JS
JS JB
215.00 ± 198.97 (5) 64.50 ± 102.44 (4)
JB JB
JS JB
80.95 ± 99.61 (22) 106.15 ± 118.30 (27)
1JS ffi Japanese Shorthorn; JB ffi Japanese Black. 2Mean ± S.D. (No. of licking pairs). TABLE V Number of animals that preferred to lick dominant or subordinate animals, and average licking time Preferred animal
No. of licking pair
x~-value
Average licking time/pair (s)
Observed
Expected
Heifers Dominant Subordinate Same rank
44 68 2
56 56
5.14 (P < 0.025)
77.57 101.50
Steers Dominant Subordinate
28 38
33 33
0.76
121,39 83.34
Analysis of variance
F~I 0 = 0.95
FI4 ffi 1.76
T a b l e V I s h o w s t h e r e l a t i o n s h i p b e t w e e n social licking a n d closeness o f a licking p a i r in t h e d o m i n a n c e o r d e r . A l t h o u g h t h e a n i m a l s c h o s e t h e licking p a r t n e r s a t r a n d o m , regardless o f d i f f e r e n c e s in d o m i n a n c e r a n k , t h e a n i m a l s closest in d o m i n a n c e o r d e r t e n d e d t o lick e a c h o t h e r f o r a l o n g e r t i m e t h a n did animals r e m o t e in r a n k . R e i n h a r d t a n d R e i n h a r d t ( 1 9 7 5 ) r e p o r t e d t h a t t h e animals o f similar d o m i n a n c e are o f t e n fighting a n d socially straining. P r o l o n g e d social licking a m o n g t h e a n i m a l s closest in d o m i n a n c e o r d e r m a y
31 TABLE VI Comparison among licking pairs in each grade of dominance rank difference between licker and lickee Dominance rank difference
No. of licking pair Observed
x2-value
Expected
Average licking time/pair
Analysis of variance
(s) Heifers 0--6 6.5--11.5 12--17 18--23
47 34 25 8
50.0 32.2 23.1 8.7
0.493
114.19 110.41 47.16 22.00
F~I 0 ffi 2.73 (P < 0.05)
Steers 0--5.5 6--11 11.5--16.5 17--22
28 20 13 5
26.4 22.2 12.3 5.2
0.363
126.57 96.70 63.08 53.60
F~2 = 1.21
TABLE VH Spearman's coefficient of rank correlation Time spent licking Giving Heifers Time spent licking Giving Receiving Social dominance Weight gain Steers Time spent licking Giving Receiving Social dominance Weight gain
1.000
Weight gain
Receiving
0.007 1.000
1.000
Social dominance
-0.218 1.000
0.129 0.176 1.000
-0.026 0.289" 0.360** 1.000
0.309* -0.006 1.000
0.024 0.278* 0.308" 1.000
*P < 0.2; **P < 0.1. r e l a x this social t e n s i o n . F u r t h e r strict research using a d u l t animals is necess a r y t o h e l p clarify this h y p o t h e s i s . T a b l e V I I s h o w s t h e r e l a t i o n s h i p s o f t h e licking r e s p o n s e t o social d o m i n a n c e a n d w e i g h t gain o f calves. A l t h o u g h n o n e o f S p e a r m a n ' s c o e f f i c i e n t s o f r a n k c o r r e l a t i o n in T a b l e V I I was significant, it is n o t e w o r t h y t h a t t h e
32
time spent receiving licking and the weight gain tended to be positively correlated (P < 0.2). W o o d (1977) found that the time spent receiving licking and milk weight were significantly related. These results suggest that social licking results not only in cleaning the skin and hair of the passive partner, but also leads to psychological stability. ACKNOWLEDGEMENTS T h e a u t h o r wishes t o t h a n k t h e K a w a t a b i F a r m o f T o h o k u University f o r permission t o use t h e i r cattle and facilities, and particularly t h a n k s Mr. T. Isawa f o r his assistance in this w o r k . G r a t e f u l a c k n o w l e d g e m e n t s are also e x t e n d e d t o Prof. Dr. K. Hayashi for his helpful advice, and Prof. Dr. Z. Kurosaki and Prof. Dr. R. F u k u h a r a for t h e i r c o m m e n t s o n t h e m a n u s c r i p t .
REFERENCES Reinhardt, V. and Reinhardt, A., 1975. Dynamics of social hierarchy in a dairy herd. Z. Tierpsychol., 38: 315--323. Sambraus, H.H., 1969. Das Sozial~ Lecken des Rindes. Z. Tierpsychol., 26: 805--810. Sato, S., Ito, I. and Hayashi, K., 1976a. Studies on the spatial pattern of grazing cattle. II. The influence of seasons and the paddock size. J. Jpn. Grassl. Sci., 22:313--318 (in Japanese, with English abstract). Sato, S., Yamagishi, T. and Mizuma, Y., 1976b. Studies on the separation and integration of grazing cattle. J. Jpn. Grassl. Sci., 22:307--312 (in Japanese, with English abstract). Wood, M.T., 1975. Social grooming patterns of dairy cattle. Proc. N.Z. Soc. Anim. Prod., 35: 219--220. Wood, M.T., 1977. Social grooming patterns in two herds of monozygotic twin dairy cows. Anita. Behav., 25: 635--642.
25
Elsevier Science Publishers B.V., ~ m . t e r d a m - - Printed in The Netherlands
SOCIAL LICKING PATTERN AND ITS RELATIONSHIPS TO SOCIAL DOMINANCE AND LIVE WEIGHT GAIN IN WEANED CALVES
SYUSUKE SATO
Department of Animal Science, Faculty of Agriculture, Miyazaki University, Miyazaki 880 (Japan) (Accepted for publication 23 February 1983)
ABSTRACT Sato, S., 1984. Social licking pattern and its relationships to social dominance and live weight gain in weaned calves. Appl. Anita. Behav. Sci., 12: 25--32. Social licking patterns of heifer and steer herds were observed and recorded during periods of resting and intermittent feeding. The results revealed the following features: (1) heifers and steers had 15.0 and 15.2 social licking interactions per hour which lasted for 37.8 and 41.0 s on average, respectively. The average time an animal spent licking was about 25 s per hour; (2) all the animals in the herds were licked by others, but only 72.3% o f the animals licked other animals; (3) the animals close in the social hierarchy tended to lick each other for a longer time than did remote animals; (4) the time receiving licking and weight gain tended to be positively correlated. The observations suggest that (1) the motivation o f giving licking may be individual-specific and may be influenced b y genetic factors, while that of receiving licking appears to be general, a n d that (2) social licking may mean not only cleaning the skin and hair o f a passive partner, but also leading it to psychological stability.
INTRODUCTION
In the field of cattle management, appeasing relationships have been less emphasized than hostile relationships such as social dominance. Sambraus (1969) and Wood (1975, 1977) suggested that social licking can be used as an index of affiliative relationship between two cows. In addition, Wood (1975) reported that "grooming is important as a behaviour leading to social stability within a herd". If the above ideas on social licking are supported, the weight gain of growing cattle may be positively correlated with social licking. From this point of view, the present study was designed to obtain some fundamental information about social licking patterns and the relationships of social licking to social dominance and weight gain of growing cattle.
0168-1591/84/$03.00
© 1984 Elsevier Science Publishers B.V.
26
MATERIALS AND METHODS Observations were made Qn 2 herds of weaned steer and heifer calves kept in adjacent pen barns during the first winter after weaning.
Animals and management The calves used in this study were born at the Kawatabi Farm of T o h o k u University from February to May in 1978. The animals were de-homed prior to weaning, and the male calves were castrated at about 5 months of age. The calves were weaned at around the middle of December 1978, and were allocated to one of t w o pen barns b y sex. Figure 1 shows the outline of the adjacent pen barns used. The barns had 1.3-m high fences, and the floors were covered with rice straw. The weaned calves were fed concentrates (2-2.5 kg/head/day), silage (5 kg/head/day) and hay (4--5 kg/head/day) twice a day at 9.00 a.m. and 3.00 p.m. Rice straw and water were provided ad libitum.
t
FEED TROUGH
HEIFERS
WATER
P
T
TROUGH
k\\\\\
FEED TROUGH
l
STEERS
N
I
__
16 8
JAPANESE BLAC
10
JAPANESESHOR HORN
11
SHORTHORN x BACK
<
9M
~<
Fig. 1. Plan of pen barns for raising cattle.
--
2
9M
>
J
l
OBSERVATORY (3M IN HEIGHT)
The herd of steer calves consisted of 10 Japanese Blacks, 11 Japanese Shorthorns and 2 crossbreds (Japanese Shorthorn X Japanese Blacks), while the herd of heifer calves consisted of 16 Japanese Blacks and 8 Japanese Shorthorns. The calves were half-sibs of each other within a breed. Freezebranding, ear-tagging and neck-tagging were done so that all the animals could be identified clearly from all directions.
Observations (1) Social licking. Observations of social licking patterns of calves were
27 carried o u t for the duration o f resting or intermittent feeding, when social licking is often observed. An observer stood on an observatory, 3 m high, at the south-east corner of the pen barns, and checked the behaviour of the animals using binoculars. The heifer herd was observed for a total 18.5 h from 17 January to 1 February, and the steer herd was observed for a total 10.5 h from 27 February to 6 March. The animals seen giving and/or receiving social licking were identified, and the time spent licking the b o d y surfaces was recorded with a stopwatch. Vulva-, penis- and udder-licking were excluded from the data. (2) Social dominance. The dominance relationships in the herds of heifer and steer calves were observed from 16 January to 15 February and from 27 February to 30 March 1979, respectively. All clear indications of social dominance were recorded when both dominant and subordinate animals were identified. The animals in heat and the animals which showed mere displacements at the feed and water troughs were omitted. The rank orders of animals in the herds were detemrined by the proportion of dominance behaviour the animal showed. (3) Weight gain. The calves were weighed on 18 December 1978 and 11 April 1979. Since the weight gain, which was taken as the difference between these 2 live weights, differed markedly by breed and sex, it was converted to a ratio o f the individual's weight gain to the mean weight gain by breed and sex. RESULTS AND DISCUSSION The results of social licking patterns of the calves are summarised in Table I. Fifteen and 15.2 incidents of social licking interactions per hour were obTABLE I Summary of data Herd of heifers No. of animals 24 Total observation time (h) 18.5 Licking interactions (times/h) 15.0 Time spent licking (s/h) 566.3 (s/interaction) 37.8 Time an animal spent giving licking (%)1
Range
0--3.826
Mean 0.655 Time an animal spent receiving licking (%)1
Herd of steers
23 10.5 15.2
625.3 41.0
0--6.362 0.755
Range
0.011--1.428
0.093--2.468
Mean
0.655
0.755
i Time spent licking Total observation time
x 10o.
28
served in herds of heifers and steers, respectively. The interactions lasted for 37.8 s and 41.0 s on average, respectively, during the observation time. The average times an animal spent in social licking were 23.6 and 27.2 s per hour in the herds of heifers and steers, respectively. Wood (1977) reported that the average time an animal spent in social licking in 2 monozygotic-twin herds of 104 cows and 40 heifers was about 7.5 s per hour. The areas available to these herds ranged from 0.77 to 1.42 ha. Sato et al. (1982, unpublished data) observed average licking times of 2.04 s per hour for a dairy herd of 61 animals in an area of 0.135 ha, and 45.21 and 35.88 s per hour for herds of 6 feeder calves of 4 and 6 months of age in pens of 37 m ~, respectively. These data indicate that age and density, as well as friendliness, may influence the time spent in social licking. It is noticeable that individual difference in time spent licking is greater than that in time spent receiving licking. Five heifers and 8 steers never licked any other calves, while all the calves were licked by other calves. The difference between the range (0--3.826% in heifers and 0--6.362% in steers) of time an animal spent licking and that (0.011--1.428% in heifers and 0.093--2.468% in steers) spent receiving licking may reflect the difference between the motivations of the licker and the lickee. As Sambraus (1969) pointed out, the motivation of the active partner may be to the specific individual, while that of the passive partner appears to be general and clear-cut (e.g. irritating stimuli). The time an animal spent licking did not differ by sex, but differed significantly by breed (P < 0.05). The time an animal spent receiving licking did not differ by sex or breed. ×2 tests for the numbers of licking partners (Table II) show that Japanese Black calves gave significantly more licking interactions than Japanese Shorthorn calves (P < 0.01). It is u n k n o w n whether this tendency was contributed by breed or by sire, because all the animals were
TABLE II ×2 tests for the numbers of animals socially licked by Japanese Shorthorns and Japanese Blacks Breed'
Observed number
Expected number
x2-value
Heifers JS JB
21 93
38.0 76.0
11.41"*
Steers JS JB
9 49
30.4 27.6
31.66"*
' JS ffi Japanese Shorthorn; JB = Japanese Black. **P < 0.01.
29
half-sibs of each other within a breed. In any case, the genetic factors appear to influence the motivation of licking animals. In order to ascertain whether the animal giving social licking t o o k the breed of its licking partners into account, the licking partners were grouped according to breed. The observed numbers of licking partners were compared to the expected numbers (Table III), and the average licking times per licking pair were compared between the 2 groups (Table IV). Tables III and IV show that Japanese Blacks tended to lick their own breeds more than the other breeds, while Japanese Shorthorns did not express preference for their own breed. The Japanese Shorthorns at the Kawatabi Farm of Tohoku University have been considered to be socially independent of neighbours, because of weak following-behaviour and a dispersive tendency during grazing (Sato et al., 1976a,b). This socially independent disposition of Japanese Shorthorns may be attributed to fewer licking interactions and the preference for a licking partner regardless o f breed.
TABLE III ×2 tests for the numbers of animals that socially licked the Japanese Shorthorns and the Japanese Blacks
Breed1 Licker
Observed
Expected
number
number
x 2.value
Lickee
Heifers
JS JS
JS JB
7 14
6.4 14.6
0.081
JB JB
JS JB
27 66
32.3 60.7
1.332 (P < 0.25)
Steers JS
JS
5
4.5
JS
JB
4
4.5
JB JB
JS JB
22 27
27.0 22.1
0.111 2.012 (P 0.175)
JS = Japanese Shorthorn; JB = Japanese Black. Table V shows the mean licking time per licking pair, with special reference to social order. Although the dominants tended to select subordinates as licking partners when giving licking, they did n o t always spend more time in licking subordinates than the subordinates did in licking the dominants. As the animals used in this study were immature and had been reared together since birth, their dominance relationships were not established completely and bidirectiolially. Therefore, the dominance relationship may be very loosely related with the social licking relationship.
30 TABLE IV Breed comparison between times (s/licking pair) spent licking Breed I
Time x (s/licking pair)
Licker
Lickee
Heifers JS JS
JS JB
28.43 ± 36.88 (7) 38.57 ± 41.08 (14)
JB JB
JS JB
94.52 ± 112.67 (27) 108.86 ± 143.88 (66)
Steers JS JS
JS JB
215.00 ± 198.97 (5) 64.50 ± 102.44 (4)
JB JB
JS JB
80.95 ± 99.61 (22) 106.15 ± 118.30 (27)
1JS ffi Japanese Shorthorn; JB ffi Japanese Black. 2Mean ± S.D. (No. of licking pairs). TABLE V Number of animals that preferred to lick dominant or subordinate animals, and average licking time Preferred animal
No. of licking pair
x~-value
Average licking time/pair (s)
Observed
Expected
Heifers Dominant Subordinate Same rank
44 68 2
56 56
5.14 (P < 0.025)
77.57 101.50
Steers Dominant Subordinate
28 38
33 33
0.76
121,39 83.34
Analysis of variance
F~I 0 = 0.95
FI4 ffi 1.76
T a b l e V I s h o w s t h e r e l a t i o n s h i p b e t w e e n social licking a n d closeness o f a licking p a i r in t h e d o m i n a n c e o r d e r . A l t h o u g h t h e a n i m a l s c h o s e t h e licking p a r t n e r s a t r a n d o m , regardless o f d i f f e r e n c e s in d o m i n a n c e r a n k , t h e a n i m a l s closest in d o m i n a n c e o r d e r t e n d e d t o lick e a c h o t h e r f o r a l o n g e r t i m e t h a n did animals r e m o t e in r a n k . R e i n h a r d t a n d R e i n h a r d t ( 1 9 7 5 ) r e p o r t e d t h a t t h e animals o f similar d o m i n a n c e are o f t e n fighting a n d socially straining. P r o l o n g e d social licking a m o n g t h e a n i m a l s closest in d o m i n a n c e o r d e r m a y
31 TABLE VI Comparison among licking pairs in each grade of dominance rank difference between licker and lickee Dominance rank difference
No. of licking pair Observed
x2-value
Expected
Average licking time/pair
Analysis of variance
(s) Heifers 0--6 6.5--11.5 12--17 18--23
47 34 25 8
50.0 32.2 23.1 8.7
0.493
114.19 110.41 47.16 22.00
F~I 0 ffi 2.73 (P < 0.05)
Steers 0--5.5 6--11 11.5--16.5 17--22
28 20 13 5
26.4 22.2 12.3 5.2
0.363
126.57 96.70 63.08 53.60
F~2 = 1.21
TABLE VH Spearman's coefficient of rank correlation Time spent licking Giving Heifers Time spent licking Giving Receiving Social dominance Weight gain Steers Time spent licking Giving Receiving Social dominance Weight gain
1.000
Weight gain
Receiving
0.007 1.000
1.000
Social dominance
-0.218 1.000
0.129 0.176 1.000
-0.026 0.289" 0.360** 1.000
0.309* -0.006 1.000
0.024 0.278* 0.308" 1.000
*P < 0.2; **P < 0.1. r e l a x this social t e n s i o n . F u r t h e r strict research using a d u l t animals is necess a r y t o h e l p clarify this h y p o t h e s i s . T a b l e V I I s h o w s t h e r e l a t i o n s h i p s o f t h e licking r e s p o n s e t o social d o m i n a n c e a n d w e i g h t gain o f calves. A l t h o u g h n o n e o f S p e a r m a n ' s c o e f f i c i e n t s o f r a n k c o r r e l a t i o n in T a b l e V I I was significant, it is n o t e w o r t h y t h a t t h e
32
time spent receiving licking and the weight gain tended to be positively correlated (P < 0.2). W o o d (1977) found that the time spent receiving licking and milk weight were significantly related. These results suggest that social licking results not only in cleaning the skin and hair of the passive partner, but also leads to psychological stability. ACKNOWLEDGEMENTS T h e a u t h o r wishes t o t h a n k t h e K a w a t a b i F a r m o f T o h o k u University f o r permission t o use t h e i r cattle and facilities, and particularly t h a n k s Mr. T. Isawa f o r his assistance in this w o r k . G r a t e f u l a c k n o w l e d g e m e n t s are also e x t e n d e d t o Prof. Dr. K. Hayashi for his helpful advice, and Prof. Dr. Z. Kurosaki and Prof. Dr. R. F u k u h a r a for t h e i r c o m m e n t s o n t h e m a n u s c r i p t .
REFERENCES Reinhardt, V. and Reinhardt, A., 1975. Dynamics of social hierarchy in a dairy herd. Z. Tierpsychol., 38: 315--323. Sambraus, H.H., 1969. Das Sozial~ Lecken des Rindes. Z. Tierpsychol., 26: 805--810. Sato, S., Ito, I. and Hayashi, K., 1976a. Studies on the spatial pattern of grazing cattle. II. The influence of seasons and the paddock size. J. Jpn. Grassl. Sci., 22:313--318 (in Japanese, with English abstract). Sato, S., Yamagishi, T. and Mizuma, Y., 1976b. Studies on the separation and integration of grazing cattle. J. Jpn. Grassl. Sci., 22:307--312 (in Japanese, with English abstract). Wood, M.T., 1975. Social grooming patterns of dairy cattle. Proc. N.Z. Soc. Anim. Prod., 35: 219--220. Wood, M.T., 1977. Social grooming patterns in two herds of monozygotic twin dairy cows. Anita. Behav., 25: 635--642.