The selected method of introducing replacements into the flock is generally influenced by breeding policy and farmer preference, as discussed on the previous page. The replacement policy selected should also take account of the financial impact.

Teagasc sheep specialist Shane McHugh outlines an example cost comparison of the three replacement policies and important aspects to consider in finding the most suitable system for your flock.

The option of purchasing hoggets in autumn breeding sales is the most straightforward and simplest system to manage. It suits a system where the focus is on high-performing terminal rams.

However, Shane says it does have limitations in improving the genetic merit of the breeding flock and also requires a good flock health and quarantine protocol to prevent disease entering the flock.

Taking a standard average cost of €170 for hoggets and a cull ewe value across the flock of €68, the net replacement cost over five years works out at €21.60 per ewe.

Table 2 looks at the option of purchasing or retaining hoggets and running dry over the winter. In this scenario, Shane says it is important to consider the impact that dry hoggets will have on the stocking rate and grass demand at key stages throughout the year.

The system is lower labour when compared with breeding from ewe lambs and suits retaining home-reared replacements best.

On lowly-stocked farms, where there is resistance to increased ewe numbers, it also provides a means of increasing the stocking rate and farm output. Taking standard production costs, the system has a net replacement cost of €13.78 per ewe.

The lowest cost option is breeding from ewe lambs. However, Shane cautions that the budget detailed in Table 3 is based on good management practices in place to deal with a more complex system and achieving high levels of performance.

It is based on 80% of ewe lambs mated going in lamb, a litter size of 1.2 lambs per hogget lambed and one lamb weaned per hogget lambed. Meal feeding to hoggets is continued for three weeks post-lambing and lambs are supplemented with creep feeding up until weaning.

The system offers faster flock improvement and the potential to achieve higher lifetime production. Shane stresses that high level of management is required. This is detailed in further detail on page 8. Operating a breeding ewe lamb flock will also generally require a higher replacement rate of 22% to 24%.

Realistic budgets

Shane advises flock owners to carry out their own budget using realistic costs for their farm. He adds that while one system may compare favourably against another, this should not be the sole factor on which decisions are based and that the policy selected has to suit you and your farm’s circumstances. The three systems will be detailed in greater detail along with farmer experience and lessons learned in the coming weeks.