Putting Merino weaner management recommendations to the test

Abstract

Merino weaner survival is poor under normal traditional management practices. Data from four trials conducted between 2001 and 2005 were used to assess the effectiveness of current industry recommendations to achieve 95% survival rates of Merino weaners. There was very little difference between 2001 and 2003 in survival of Merino weaners despite average weaning weight ranging from 20 to 24 kg between years. The recommended target weaning weight of 23 kg does not always appear to be a good predictor of survival. However, a target of 45% mature liveweight at pasture senescence achieved the industry recommendation of 95% weaner survival. Merino weaners were fed over the summer–autumn period to reach 40 kg liveweight by the time green feed became available. Weaner survival reached 93% compared with 89% survival to hogget shearing in weaners managed under normal growth paths. Furthermore, twice as many ewe weaners died in the traditional feeding program compared with the well fed ewe weaners. Differences in mortality between feeding levels in the wether weaners was less than that observed in the ewe weaners. Flock average growth rates were not useful indicators of weaner survival and there was no relationship between Merino ram estimated breeding values for weaning weight and the survival of the progeny.