The magnitude of reproductive wastage to lamb marking in 30 Merino flocks in south-west Queensland.

Thirty groups of Merino ewes in 6 districts of south-west Queensland were studied between 1976 and 1985 to determine the magnitude of reproductive wastage to lamb making. Relatively high pregnancy rates (77 to 100%, mean 93%) and a wide range of lamb marking percentages (10 to 115%, mean 78%) were recorded. The mean reproductive wastage due to failure to mate and failure to lamb was low (1.6 and 3.4% respectively) in 8 flocks where harnessed rams were used. This indicated that loss of lambs from birth to lamb making was the major cause of reproductive wastage in most years.