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Temporal distribution
and grouping of suckling events on water buffalo calves
L. Brusius, L.C. Pinheiro
Machado Filho, P.A.D. Coimbra, M.J. Hötzel, M.C. Yunes, C.T. Berton,
M. Ouriques, J.A.R. Ribeiro and
S.A. F. de Quadros
Lab. Etologia Aplicada,
Dep. De Zootecnia & Des. Rural, Universidade Federal de Santa Catarina,
Florianópolis, SC, Brasil
Understanding the behaviour of species in free-range conditions may help in the design of species-appropriate management strategies that are not harmful for the welfare of animals. In a previous study we found a suckling interval of 7 hours for water-buffaloes. If suckling occurs at long intervals, and if it is influenced by social facilitation, then a clustering of suckling events among cow-calf pairs over 24 hours may occur. We evaluated the temporal distribution and a possible grouping of suckling events over a 24-hour period in two water-buffalo herds raised on pasture. Five and eight cow-calf pairs were randomly chosen from a herd of 12 (Ressacada-RS) and 36 (São José-SJ) cows, respectively. The calves were directly and continuously observed for 48 hours at ages 0, 2 and 5 months. Every suckling bout of the focal animals was recorded from beginning to end of the event. To evaluate the temporal distribution of suckling events within each age, they were arranged in eight periods of 3 hours/24 hours. To evaluate if suckling events were grouped, the number of solitary suckling events and those occurring in a cluster, each day, were compared within each herd and age. Data were analysed using the Chi-square test. There was a significant effect of period on the frequency of suckling at ages 0 (chi-square=14.72, P<0.04) and 2 (chi-square=17.56, P<0.014) months, but not at 5 months (P>0.28). At younger ages suckling frequency was higher early in the morning (6 AM to 9 AM) and lower from midnight to 6 AM. In the SJ herd the number of solitary and clustered sucklings did not differ at any age (P>0.09). In the RS herd there were more solitary than grouped suckling events during months 0 (chi-square=4.12, P<0.04) and 2 (chi-square=11.64, P<0.01). We conclude that suckling events were not randomly distributed over 24 h. However, group suckling, which would suggest social facilitation of this behaviour, was not clearly identified and requires further investigation.