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Data on lamb survival and associated traits involving records from 15 192 lambs, 6308 dams and 284 sires from the Sheep CRC’s Information Nucleus were studied. Lamb survival to 3 days of age and to weaning was 85 and 80%, respectively, and heritability (±s.e.) was 0.014 ± 0.010 and 0.010 ± 0.010, respectively. Of the 14 traits recorded at birth, time taken for the lamb to bleat, rectal temperature and crown–rump length had the highest genetic correlations with lamb survival to weaning (–0.43 ± 0.32, 0.56 ± 0.33 and –0.38 ± 0.36, respectively). Under selection for a multi-trait objective including net reproduction rate (but not lamb survival), survival was predicted to decline genetically by 0.25 lambs weaned per 100 lambs born.year, although this was reversed to a gain of 0.20 lambs weaned per 100 lambs born.year by including the trait in the breeding objective and using 50 half-sib and 50 progeny records per selection candidate. Accuracy of selection for lamb survival was improved to 0.735 with a selection index of lamb survival to weaning, lamb ease, birth coat score, time taken to bleat, rectal temperature and crown–rump length, with the addition of 50 half-sibs and 50 progeny records per candidate. Our results suggest that unless actively incorporated into breeding objectives, lamb survival may genetically decline; however, gains are possible with direct selection using half-sib and progeny records. The addition of indirect selection criteria for lamb survival can further improve accuracy, up to 93.4%, but requires further investigation.

Consumer discrimination against meat products from animals treated with hormones has provided the impetus to investigate alternative ways of boosting feed conversion efficiency and growth rates of animals and to manipulate the reproductive capacity of animals. In view of the longevity of the immune response to specific antigens and the realization that antibodies are capable of neutralizing or mimicking the actions of hormones, vaccination techniques have been explored as alternatives to hormone administration to boost animal productivity. To date, only two commercial vaccines are available to improve the efficiency of production, although neither is related to the stimulation of growth efficiency: Fecundin (registered product, Glaxo Pty Ltd) is designed to improve lambing percentages, and Vaxstrate (registered product, Arthur Webster & Co.) to prevent reproductive activity. In this review, recent advances in vaccine development are explored together with some of the problems encountered in research in this field.

Dryland farming and its profitability is directly affected by the amount and timing of rainfall that influence and consequently impacts on pasture and crop yields. Yet rainfall is not the sole determinant of farm enterprise profitability; prices of farm inputs and commodities produced also affect farm profits. This study draws on farm commodity prices and input prices from the past 9 years to form correlated price and cost datasets that are then used in examining the profitability of a range of farm enterprises in south eastern Australia under low, average and high rainfall scenarios. Fourteen representative farm enterprises were examined that included the production of Merino fine wool, prime lamb, beef cattle, milk, wheat and canola. The spread of profitability of these farm enterprises against the backdrop of price variability and rainfall scenarios was compared. The results show that profitability of the enterprises studied is currently affected more by changes in rainfall than by commodity prices and that dairy enterprises are the most profitable on a $/ha basis but that the profitability of wheat, steer and prime lamb enterprises are least affected by low rainfall scenarios. The self-replacing cow–calf beef systems, canola and dairy enterprises are the most vulnerable to reduced rainfall and may benefit by reducing profit risk through changes such as expanding the enterprise or diversifying across other types of enterprises. Farm diversification involving combinations of enterprises with negatively correlated profits will enable the variance in farm profits to be reduced. Such actions could form part of farms’ adaptation strategies to climate and price variability.