Economics of feeding energy-based supplements to grazing ewes before mating in order to increase the reproduction rate of a wool-producing flock

Abstract

The financial wisdom of feeding energy-based supplements to ewes before mating to increase fecundity was evaluated using mathematical models of sheep production systems. It was concluded that, for a wool-producing enterprise in southern Australia, feeding supplements to ewes pre-mating is likely to be highly unprofitable. This is partly because relatively few ewes would have extra ova and also because multiple embryos and lambs have a lower probability of survival than single embryos and lambs. Further more, the extra lambs reared would be associated with an increase in grazing pressure which would necessitate a reduction in either stocking rate or in ewe liveweight at mating and thus fecundity in the subsequent season.