. 2007. Patterns of maternal-offspring behaviour of dairy sheep and potential association with mammary health. Can. J. Anim. Sci. 87: 469-478. Behaviour during lactation and its relationship with mammary health was investigated in 12 dairy ewes (six with single lambs and six with twins) for 42 d after lambing. Behavioural recordings were made. Samples of teat duct material and of mammary secretion were collected for bacteriological and cytological examination. Ewes performed similar patterns of behaviour as those described in the literature for meat breeds, but with some differences. No negative maternal behaviours were observed; ewes showed reduced "Grooming" and "Sniffing" immediately post-partum. Of 480 duct or secretion samples, 39 and 3, respectively (P < 0.001), yielded bacteria. There was no difference in the frequency of bacterial isolation from ewes suckling singles or twins: 46 and 54% of isolates, respectively (P = 0.637). There was greater frequency of bacterial isolation during the first stage of lactation (day 0-day 3), 0.125, compared with the second (day 4-day 11), 0.083, the third (day 12-day 30), 0.063, and the fourth (day 31-day 42), 0.069 (P < 0.001). There was also greater frequency of positive California Mastitis Test scores during the first stage of lactation, 0.917, compared with that in stages 2 (0.550), 3 (0.140) and 4 (0.181) (P < 0.001). There was decreasing duration of "Sucking attempt" and "Successful suck" throughout lactation (P < 0.05). There was increasing frequency of "Hindering sucking" and of "Head up posture" from first to subsequent stages of lactation (P = 0.038 and P = 0.002), whilst "Hindering sucking" coincided with end of "Sucking bouts" of lambs. It is concluded that termination of lamb's sucking activity by the ewe when her mammary glands have been emptied may prevent damage to the teat and likely development of mastitis. Furthermore, frequent and longer sucking events by lambs during early lactation, may contribute to increased bacterial recoveries from mammary glands of ewes.Key words: Sheep, maternal behaviour, mastitis, sucking, post-partum period, lactation, mammary infection Gougoulis, D. A., Kyriazakis, I., Mavrogianni, V. S., Fragkou, A. A., Skoufos, J., Tzora, A., Taitzoglou, I. A., Kokoli, A. N. et Fthenakis, G. C. 2007. Comportement des brebis laitières avec leur progéniture et liens éventuels avec la santé du pis. Can. J. Anim. Sci. 87: 469-478. Les auteurs ont étudié le comportement de 12 brebis laitières (6 avec un agneau et 6 avec des jumeaux) durant la lactation au cours des 42 jours qui ont suivi l'agnelage en vue d'établir un lien avec la santé mammaire. Ils ont noté les comportements et prélevé des échantillons des trayons ainsi que des sécrétions mammaires pour analyse bactériologique et cytologique. Les brebis se comportent de la même façon que les races à viande, selon la description donnée dans la littérature, outre quelques variations. Les auteurs n'ont remarqué aucun comportement négatif de la mère; les brebis se nettoient et reniflent moins...