Some benefits and costs of genetic improvement in New Zealand's sheep and beef cattle industry

Abstract

Estimated physical returns and their calculated value net of food costs have been used as the basis for an analysis of discounted costs and returns from a selection programme for a 200-ewe flock and a 100-cow beef herd. Recording costs (computing, labour, tags, and scales) of $1-2 per ewe and $2-3 per cow are assumed, with a discount rate of 10% as used by the New Zealand Treasury. It is also assumed that no stock for breeding were purchased or sold. Results are expressed in 1979 dollars, for 1 year or round of selection applied. The net present value of 10 years of selection is $4950 or $3600 in sheep ($1 or $2 per ewe in costs) and $3670-4870 in beef cattle, depending on recording costs and the assumed level of food costs incurred by the herd in achieving higher weight-for-age. With sheep, net production is much more important than fleece weight in its contribution to higher profits. A very important contribution in the beef herd under consideration is the return from a higher net calf crop; even small percentage biological gains are of great economic importance. Net returns for a breeder also selling stock for breeding would probably be much higher.

Predicting ecological change in tussock grasslands of Aotearoa New Zealand

“…Conifers and hawkweeds can also impact ecosystem functioning by altering soil microbial communities (Dickie et al 2010;Morman 2021). Generally, exotic and invasive plants are most abundant at low elevations and in disturbed areas, which corresponds with dominance of short tussock grasslands and where management is most intensive (Day & Buckley 2011, 2013. With changing climates, there is potential for new plants to become invasive and for present invasive plants to expand their ranges and spread upslope (e.g.…”

“…conditions in elevation, aspect, drainage, management, pest densities). Predictions are further challenged by likely legacy effects of past management regimes common over 100 years ago, such as burning and oversowing of pasture species, and high stocking densities well above those used now in at least some areas of the high country (O 'Connor 1982;Morris 2013).…”

Relative economic value estimates of grasscutter production traits

“…Culled does and bucks were disposed off at 90% of the expected weight of marketed does and bucks, respectively to compensate for wastage resulting from old age (Morris, 1980). Average life cycle of a breeding doe ended at 60 months and age at first parturition was 11.9 months.…”