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Relation between milking order and dominance value in a group of dairy cows
Applied Animal Ethology, 2 (1976) 271-276 o Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
271
Short Communication RELATION BETWEEN MILKING ORDER AND DOMINANCE A GROUP OF DAIRY COWS
VALUE IN
MONIQUE SOFFIE, G. THIN&S and G. DE MARNEFFE Centre de Psychologie Pellenberg (Belgium)
Expkrimentale
et Comparee,
Universitk
de Louvain,
3041
(Received April 28th, 1975)
ABSTRACT Soffie, M., Thin&s, G. and De Marneffe, G., 1976. Relation between milking order and dominance value in a group of dairy cows. Appl. Anim. Ethel., 2: 271-276. A group of Friesian Dutch dairy cows (varying between 34 to 60 individuals) in an open stall system was observed for a period of 1 year. The milking order and the dominance order of the group were determined. Results show that (1) the order of entrance of the herd to the milking parlor is systematic; (2) the same animal leads at the exit of the yard and at the entrance to the milking parlor; the order of the rest of the herd is not the same; (3) the leading animal occupies a high social position but is not the dominant of the whole group; (4) there is a low positive correlation between the order of entrance to the milking parlor and the dominance order; (5) high correlations between all periods were found for milking order and for dominance value; (6) there is no correlation between milk production and milking order or dominance rank.
INTRODUCTION
In this study, we recorded the movements of a herd of dairy cows towards their milking parlor. This so-called milking order was established in two places: at the exit of the yard, and at the entrance to the milking parlor. These two sub-orders were observed separately because the animals had the possibility of redistributing themselves differently in the space between the exit and the entrance points (Fig.1). Besides, the movements at the exit of the yard appeared to be freer than those at the entrance of the milking parlor, where the animals were, among other things, forced gently inside by a rotating gate. Once established, the milking order was correlated with dominance value and milk production. METHODS
The observations were carried out on a dairy farm. The group observed included a majority of Friesian dairy cows and a few individuals of other races
272
(Flemish breed and Canadian Holstein). The bull was of pure Holstein race. The open stall system in which the observations took place has been described previously (Thin&s et al., 1975). The observations on the milking order lasted 13 months (from May 1972 to June 1973). During this period, the herd underwent several changes due to departures and arrivals. A total number of 56 animals was observed in spite of these fluctuations. The number of animals present in any one period was never less than 34. The total number of observations was distributed over eight distinct periods, during each of which a homogenous group was available. The number of observations (N) (two observations a day; morning and afternoon milking) was 21,15, 52, 32,28, 43, 30 and 24 during periods 1 to 8 respectively. Exits from the yard were noted simultaneously only during three of the above-mentioned periods due to darkness in winter. The number of observations was 14 (period l), 34 (period 7) and 23 (period 8). Since the animals entered the milking parlor individually the order of the whole group could be noted easily. The yard exit was sufficiently wide to allow several animals to pass in a line, so that it proved only possible to note with precision the movement of the first three individuals and of the last one. The hierarchy of the group was established by a food competition test in which the whole herd took part (Bouissou and Signoret, 1970). It consisted in placing a food container from which only one animal could feed at a time at one of two different points (A and B) in the yard. All animals had free access to the container and all thrusts occurring in this situation, with or without physical contact, were recorded. This test took place every morning before food was issued in the central feeding trough. According to usual practice, the animal who succeeded in feeding after having chased its competitor, was credited with a victory. A dominance value index was calculated for each cow according to Beilharz and Mylrea (1963 a). The correlation was calculated between milking order and transformed dominance values. RESULTS
Order of entrance to the milking parlor (milking order) For each of the eight periods of observation, the mean rank of each animal was calculated. The Friedman test shows that the order of entrance is very systematic for all series of observations (P < 0.001) (Siegel, 1956). Order at the exit of the yard For the reasons stated above, the recording of positions at the exit of the yard could not be effected for the whole herd. We have therefore only calculated the relative frequencies of passage for the three top animals and for the last one. These data are given in Table I.
273
lrinkinl
milkin(l
parlor
trou#k \
;: :: :., ;; :. ;:
‘#L container A
:ontrinsr B
Fig.1. Plan of yard and milking parlor.
Comparison of Table I and milking order seems to indicate that the leader is the same in both situations. For the individuals next to the leader however, the relationship between the two situations is apparently very slight or even non-existent. A higher stability is found for the top individual or for the first two than for the following cows (71% against 28.4 and 14.2%; 73.5% against 33.3, 32.4 and 52.9%; 56.8 and 52.2% against 14.4 and 34.8%).
274 TABLE I Relative frequencies of passage of the individual animals most frequently observed in the three top positions and in the last position at the exit of the yard. N = number of observations; t animal not present in the group during periods 7 and 8 Rank
1 2 3 Last
Period 1 N= 14
Period 7 N= 34
Period 8 N= 23
Animal number
%
Animal number
%
Animal number
%
474 598 429f
71.4 28.4 14.2
474 598 593 365
73.5 33.3 32.4 52.9
474 598 287 365
56.5 52.2 14.4 34.3
Hierarchy of the herd As was said above, the hierarchy was estimated by calculating the dominance value of each individual (Beilharz and Mylrea, 1963 a), i.e. dividing the number of individuals w by the number of encountered animals. In order to normalize the distribution, this ratio was transformed to a sine value (Dagnelie, 1970). In this manner a position could be attributed to each individual in the group. In all cases, the bull was the absolute dominant. Relation between the various observation periods With regard to the milking orders obtained during the successive periods, we considered the results with the bull (periods 2 to 8) and without it (periods 1 to 8). Periods 2 to 8 (with bull) were correlated two by two using all possible combinations. In all cases, there was a very strong correlation for the animals present in all successive periods (0.73 Q r < 0.96, P < 0.001 for N = 16) (Dagnelie, 1970). With regard to the relation between the dominance values obtained during periods 7 and 8, the correlations found for all animals present during these two periods are also very strong (r = 0.68, P < 0.001 for N = 31). The leader occupied the fourth position during these two periods. Relation between milking order and dominance value The correlations between these two variables could only be calculated for the two last periods of observation because the dominance value was estimated for the latter only. The correlation is very low for period 7 (r = 0.36, P < 0.05 for N = 35) and not significant for period 8 (r = 0.283, P > 0.05 for N = 34).
275
Relation with milk production No correlation milk production
was found between milk production and dominance value.
and milking order or
DISCUSSION
Different aspects of the relations between milking order and other variables have been considered in a number of previous studies. According to Hafez and Bouissou (1975), entrance to the milking parlor should be considered as a voluntary movement, different from free movements as observed in pastures and forced movements as in weighing and other manipulations. Beilharz and Mylrea (1963 b) state that animals acting as leaders in forced movements show a low dominance value, whereas leaders in voluntary movements tend to occupy a high social position. However, the work of Kilgour and Scott (1959) had shown that leadership and dominance values were poorly, if at all, correlated (rs = 0.1). Various authors (Kilgour and Scott, 1959; Dietrich et al., 1965; Dickson et al., 1967; Reinhardt, 1973 j agree that milking order is fairly consistent, a fact which was confirmed in the present study, contrary to Guhl and Atkeson’s (1959) statement that the movements observed in this situation were random. We found a low correlation level (P < 0.05 and P > 0.05) between milking order and dominance value, whereas Reinhardt (1973) had found a strong correlation between these two variables (P < 0.025). In our results, neither milking order nor dominance value correlate with milk production. In other studies however, a low (Dietrich et al., 1965) or not significant (Reinhardt, 1973; P > 0.1) correlation was found between milk production and milking order, while Beilharz et al. (1966) as well as Dickson et al. (1967) did not find a significant correlation between milking order and dominance value. These contradictary results can tentatively be explained by considering some differences in handling and methodology. For one thing, routine and handling practices may differ widely from one farm or plant to another. The stability of the milking order may be dependent, at least partly, on the manner in which operations are carried out, viz. according to factors such as whether a strict timing and a constant order between groups is respected, and having the same herdsman in control. Differences in the methods adopted to establish dominance values as well as the cattle breed used may also explain certain inconsistencies in the conclusions reached by various authors. ACKNOWLEDGEMENTS
This experimental study was sponsored by a grant from the Institut pour 1’Encouragement de la Recherche dans 1’Industrie et 1’Agriculture (I.R.S.I.A., Belgium).The authors express their thankfulness to Baron V. de Tornaco
276
(Exploitation of Vervoz, Belgium) who kindly put his cattle at their disposal for these observations. They also thank Professor P. Dagnelie and his collaborator Dr K. In (Facult6 des Sciences agronomiques de l’ktat, Gembloux, Belgium) for their help in the statistical analysis of data. REFERENCES Beilharz, R.G. and Mylrea, P.J., 1963 a. Social position and behaviour of dairy heifers in yard. Anim. Behav., 11: 522-528. Beilharz, R.G. and Mylrea, P.J., 1963 b. Social position and movement orders of dairy heifers. Anim. Behav., 11: 529-533. Beilharz, R.G., Butcher, D.F. and Freeman, A.E., 1966. Social dominance and milk production in Holsteins. J. Dairy Sci., 49 : 887-892. Bouissou, M.F. and Signoret, J.P., 1970. La hiCarchie sociale chez les Mammifares. Rev. Comp. Anim., 4: 43-61. Dagnelie, P., 1970. Theorie et Methodes Statistiques, I et II. Duculot, Gembloux, 378 pp., 451 pp. Dickso?, D.P., Barr, G.R. and Wieckert, D.A., 1967. Social relationship of dairy cows in a feed lot. Behaviour., 29 : 195-203. Dietrich, J.P., Snyder, W.W., Meadows, C.E. and Albright, J.L., 1965. Rank order in dairy cows. Am. Zool., 5: 713 (Abstract). Guhl, A.M. and Atkeson, F.W., 1959. Social organization in a herd of dairy cows. Trans. Kans. Acad. Sci., 62: 80-87. Hafez, E.S.E. and Bouissou, M.F., 1975. The behaviour of cattle. In: E.S.E. Hafez (Editor), The Behaviour of Domestic Animals. Bailliere Tindall, London, 3rd edn, pp. 203-237. Kilgour, R. and Scott, T.H., 1969. Leadership in a herd of dairy cows. Proc. N.Z. Sot. Anim. Prod., 19: 36-43. Reinhardt, V., 1973. Beitriige zur sozialen Rangordnung und Melkordnung bei Kiihen. Z. Tierpsychol., 32: 281-292. Schein, M.W. and Fohrman, M.H., 1955. Social dominance relationships in a herd of dairy cattle. Anim. Behav., 3: 46-55. Siegel, S., 1956. Non Parametric Statistics for the Behavioral Sciences. McGraw-Hill, New York, N.Y., 312 pp. Thin&s, G., Soffib, M. and De Marneffe, G., 1975. Aires de residence preferentielles d’un groupe de vaches laiti&es en stabulation libre. Ann. Zootech., 24 (2): 177-187.
271
Short Communication RELATION BETWEEN MILKING ORDER AND DOMINANCE A GROUP OF DAIRY COWS
VALUE IN
MONIQUE SOFFIE, G. THIN&S and G. DE MARNEFFE Centre de Psychologie Pellenberg (Belgium)
Expkrimentale
et Comparee,
Universitk
de Louvain,
3041
(Received April 28th, 1975)
ABSTRACT Soffie, M., Thin&s, G. and De Marneffe, G., 1976. Relation between milking order and dominance value in a group of dairy cows. Appl. Anim. Ethel., 2: 271-276. A group of Friesian Dutch dairy cows (varying between 34 to 60 individuals) in an open stall system was observed for a period of 1 year. The milking order and the dominance order of the group were determined. Results show that (1) the order of entrance of the herd to the milking parlor is systematic; (2) the same animal leads at the exit of the yard and at the entrance to the milking parlor; the order of the rest of the herd is not the same; (3) the leading animal occupies a high social position but is not the dominant of the whole group; (4) there is a low positive correlation between the order of entrance to the milking parlor and the dominance order; (5) high correlations between all periods were found for milking order and for dominance value; (6) there is no correlation between milk production and milking order or dominance rank.
INTRODUCTION
In this study, we recorded the movements of a herd of dairy cows towards their milking parlor. This so-called milking order was established in two places: at the exit of the yard, and at the entrance to the milking parlor. These two sub-orders were observed separately because the animals had the possibility of redistributing themselves differently in the space between the exit and the entrance points (Fig.1). Besides, the movements at the exit of the yard appeared to be freer than those at the entrance of the milking parlor, where the animals were, among other things, forced gently inside by a rotating gate. Once established, the milking order was correlated with dominance value and milk production. METHODS
The observations were carried out on a dairy farm. The group observed included a majority of Friesian dairy cows and a few individuals of other races
272
(Flemish breed and Canadian Holstein). The bull was of pure Holstein race. The open stall system in which the observations took place has been described previously (Thin&s et al., 1975). The observations on the milking order lasted 13 months (from May 1972 to June 1973). During this period, the herd underwent several changes due to departures and arrivals. A total number of 56 animals was observed in spite of these fluctuations. The number of animals present in any one period was never less than 34. The total number of observations was distributed over eight distinct periods, during each of which a homogenous group was available. The number of observations (N) (two observations a day; morning and afternoon milking) was 21,15, 52, 32,28, 43, 30 and 24 during periods 1 to 8 respectively. Exits from the yard were noted simultaneously only during three of the above-mentioned periods due to darkness in winter. The number of observations was 14 (period l), 34 (period 7) and 23 (period 8). Since the animals entered the milking parlor individually the order of the whole group could be noted easily. The yard exit was sufficiently wide to allow several animals to pass in a line, so that it proved only possible to note with precision the movement of the first three individuals and of the last one. The hierarchy of the group was established by a food competition test in which the whole herd took part (Bouissou and Signoret, 1970). It consisted in placing a food container from which only one animal could feed at a time at one of two different points (A and B) in the yard. All animals had free access to the container and all thrusts occurring in this situation, with or without physical contact, were recorded. This test took place every morning before food was issued in the central feeding trough. According to usual practice, the animal who succeeded in feeding after having chased its competitor, was credited with a victory. A dominance value index was calculated for each cow according to Beilharz and Mylrea (1963 a). The correlation was calculated between milking order and transformed dominance values. RESULTS
Order of entrance to the milking parlor (milking order) For each of the eight periods of observation, the mean rank of each animal was calculated. The Friedman test shows that the order of entrance is very systematic for all series of observations (P < 0.001) (Siegel, 1956). Order at the exit of the yard For the reasons stated above, the recording of positions at the exit of the yard could not be effected for the whole herd. We have therefore only calculated the relative frequencies of passage for the three top animals and for the last one. These data are given in Table I.
273
lrinkinl
milkin(l
parlor
trou#k \
;: :: :., ;; :. ;:
‘#L container A
:ontrinsr B
Fig.1. Plan of yard and milking parlor.
Comparison of Table I and milking order seems to indicate that the leader is the same in both situations. For the individuals next to the leader however, the relationship between the two situations is apparently very slight or even non-existent. A higher stability is found for the top individual or for the first two than for the following cows (71% against 28.4 and 14.2%; 73.5% against 33.3, 32.4 and 52.9%; 56.8 and 52.2% against 14.4 and 34.8%).
274 TABLE I Relative frequencies of passage of the individual animals most frequently observed in the three top positions and in the last position at the exit of the yard. N = number of observations; t animal not present in the group during periods 7 and 8 Rank
1 2 3 Last
Period 1 N= 14
Period 7 N= 34
Period 8 N= 23
Animal number
%
Animal number
%
Animal number
%
474 598 429f
71.4 28.4 14.2
474 598 593 365
73.5 33.3 32.4 52.9
474 598 287 365
56.5 52.2 14.4 34.3
Hierarchy of the herd As was said above, the hierarchy was estimated by calculating the dominance value of each individual (Beilharz and Mylrea, 1963 a), i.e. dividing the number of individuals w by the number of encountered animals. In order to normalize the distribution, this ratio was transformed to a sine value (Dagnelie, 1970). In this manner a position could be attributed to each individual in the group. In all cases, the bull was the absolute dominant. Relation between the various observation periods With regard to the milking orders obtained during the successive periods, we considered the results with the bull (periods 2 to 8) and without it (periods 1 to 8). Periods 2 to 8 (with bull) were correlated two by two using all possible combinations. In all cases, there was a very strong correlation for the animals present in all successive periods (0.73 Q r < 0.96, P < 0.001 for N = 16) (Dagnelie, 1970). With regard to the relation between the dominance values obtained during periods 7 and 8, the correlations found for all animals present during these two periods are also very strong (r = 0.68, P < 0.001 for N = 31). The leader occupied the fourth position during these two periods. Relation between milking order and dominance value The correlations between these two variables could only be calculated for the two last periods of observation because the dominance value was estimated for the latter only. The correlation is very low for period 7 (r = 0.36, P < 0.05 for N = 35) and not significant for period 8 (r = 0.283, P > 0.05 for N = 34).
275
Relation with milk production No correlation milk production
was found between milk production and dominance value.
and milking order or
DISCUSSION
Different aspects of the relations between milking order and other variables have been considered in a number of previous studies. According to Hafez and Bouissou (1975), entrance to the milking parlor should be considered as a voluntary movement, different from free movements as observed in pastures and forced movements as in weighing and other manipulations. Beilharz and Mylrea (1963 b) state that animals acting as leaders in forced movements show a low dominance value, whereas leaders in voluntary movements tend to occupy a high social position. However, the work of Kilgour and Scott (1959) had shown that leadership and dominance values were poorly, if at all, correlated (rs = 0.1). Various authors (Kilgour and Scott, 1959; Dietrich et al., 1965; Dickson et al., 1967; Reinhardt, 1973 j agree that milking order is fairly consistent, a fact which was confirmed in the present study, contrary to Guhl and Atkeson’s (1959) statement that the movements observed in this situation were random. We found a low correlation level (P < 0.05 and P > 0.05) between milking order and dominance value, whereas Reinhardt (1973) had found a strong correlation between these two variables (P < 0.025). In our results, neither milking order nor dominance value correlate with milk production. In other studies however, a low (Dietrich et al., 1965) or not significant (Reinhardt, 1973; P > 0.1) correlation was found between milk production and milking order, while Beilharz et al. (1966) as well as Dickson et al. (1967) did not find a significant correlation between milking order and dominance value. These contradictary results can tentatively be explained by considering some differences in handling and methodology. For one thing, routine and handling practices may differ widely from one farm or plant to another. The stability of the milking order may be dependent, at least partly, on the manner in which operations are carried out, viz. according to factors such as whether a strict timing and a constant order between groups is respected, and having the same herdsman in control. Differences in the methods adopted to establish dominance values as well as the cattle breed used may also explain certain inconsistencies in the conclusions reached by various authors. ACKNOWLEDGEMENTS
This experimental study was sponsored by a grant from the Institut pour 1’Encouragement de la Recherche dans 1’Industrie et 1’Agriculture (I.R.S.I.A., Belgium).The authors express their thankfulness to Baron V. de Tornaco
276
(Exploitation of Vervoz, Belgium) who kindly put his cattle at their disposal for these observations. They also thank Professor P. Dagnelie and his collaborator Dr K. In (Facult6 des Sciences agronomiques de l’ktat, Gembloux, Belgium) for their help in the statistical analysis of data. REFERENCES Beilharz, R.G. and Mylrea, P.J., 1963 a. Social position and behaviour of dairy heifers in yard. Anim. Behav., 11: 522-528. Beilharz, R.G. and Mylrea, P.J., 1963 b. Social position and movement orders of dairy heifers. Anim. Behav., 11: 529-533. Beilharz, R.G., Butcher, D.F. and Freeman, A.E., 1966. Social dominance and milk production in Holsteins. J. Dairy Sci., 49 : 887-892. Bouissou, M.F. and Signoret, J.P., 1970. La hiCarchie sociale chez les Mammifares. Rev. Comp. Anim., 4: 43-61. Dagnelie, P., 1970. Theorie et Methodes Statistiques, I et II. Duculot, Gembloux, 378 pp., 451 pp. Dickso?, D.P., Barr, G.R. and Wieckert, D.A., 1967. Social relationship of dairy cows in a feed lot. Behaviour., 29 : 195-203. Dietrich, J.P., Snyder, W.W., Meadows, C.E. and Albright, J.L., 1965. Rank order in dairy cows. Am. Zool., 5: 713 (Abstract). Guhl, A.M. and Atkeson, F.W., 1959. Social organization in a herd of dairy cows. Trans. Kans. Acad. Sci., 62: 80-87. Hafez, E.S.E. and Bouissou, M.F., 1975. The behaviour of cattle. In: E.S.E. Hafez (Editor), The Behaviour of Domestic Animals. Bailliere Tindall, London, 3rd edn, pp. 203-237. Kilgour, R. and Scott, T.H., 1969. Leadership in a herd of dairy cows. Proc. N.Z. Sot. Anim. Prod., 19: 36-43. Reinhardt, V., 1973. Beitriige zur sozialen Rangordnung und Melkordnung bei Kiihen. Z. Tierpsychol., 32: 281-292. Schein, M.W. and Fohrman, M.H., 1955. Social dominance relationships in a herd of dairy cattle. Anim. Behav., 3: 46-55. Siegel, S., 1956. Non Parametric Statistics for the Behavioral Sciences. McGraw-Hill, New York, N.Y., 312 pp. Thin&s, G., Soffib, M. and De Marneffe, G., 1975. Aires de residence preferentielles d’un groupe de vaches laiti&es en stabulation libre. Ann. Zootech., 24 (2): 177-187.