EWE COLOSTRUM AND SUBSEQUENT LAMB SUCKLING BEHAVIOR

Behavioural and colostral data were obtained from 70 parous Border Lei cester x Merino ewes (and their lambs) that lambed in 0.25 ha paddocks . Data collected included a colostral sample immediately postpartum, l amb weight and temperature, site of parturition and lamb sucking attem pts to 48 h post-partum. Colostrum dry matter percentage was 56.5 for ewes with single lambs and 61.5 for ewes with twins (P<0.05). Colostru m colour and consistency score (1-7) of twin-bearing ewes was 5.5 comp ared with single-bearing ewes of 6.5 (nearer normal milk). Lamb suckin g behaviour suggested the more viscous the colostrum, the more often t he lamb attempts to suck (P<0.001) and for a longer period at each att empt (P<0.05). This effect diminished over time so that by 24-48 h the re was no difference in behaviour expressed as duration x number of su cking bouts, when normal milk would be expected. Twin lambs had signif icantly more sucking bouts than single lambs up to 4 h postpartum. The consequences of these observations would be more serious for twin lam b survival and may explain why some individual twin lambs often die fr om starvation.