Feed Budget for a Drought-Declared Merino Flock
A 900-head self-replacing Merino ewe flock in the southern tablelands is entering a drought-declared summer. The ewes are joined and 70% are expected to lamb in eight weeks. Pasture availability is estimated at 400 kg dry matter per hectare over 300 ha of grazing, with 200 ha of stubble and 100 ha of failed crop. The grower has 120 t of barley in storage and can buy hay at $220/t delivered. Ewes weigh 55 kg and are in condition score 2.5, trending down. The target is to lamb at condition score 3.0 and to keep the flock together rather than sell. The farm has 40 ha of a dual-purpose cereal that could be grazed or cut for hay. Sheep are the only enterprise, and cash flow is tight until wool is sold in three months.
1. Estimate whether the standing feed and stored grain can carry the flock to lambing, showing your assumptions, and identify the shortfall.
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Assumptions: a 55 kg dry ewe in late pregnancy eats roughly 1.5-2.0 kg dry matter per day, rising to about 2.0-2.5 kg in the last weeks before lambing. Use 2.0 kg/head/day as a planning figure for the eight weeks to lambing.
Flock demand: 900 × 2.0 kg = 1,800 kg DM/day, or 1.8 t/day. Over 56 days that is about 100 t DM.
Standing feed: 300 ha × 400 kg/ha = 120 t DM, but only about half is usable before ground cover becomes too low, so about 60 t usable. Stubble and failed crop might add 20-30 t of low-quality feed. Total pasture perhaps 80-90 t.
Grain: 120 t barley, but grain should not exceed about 30-40% of the diet, so it can supply perhaps 0.6-0.8 kg/head/day, or about 30-43 t over 56 days.
Shortfall: demand about 100 t, pasture about 85 t, grain contributes about 35 t of usable energy but not bulk. The flock is short on bulk roughage and on protein, because dry stubble and barley are both low in protein for late-pregnant ewes.
2. Recommend how to use the 40 ha of dual-purpose cereal and whether to buy hay, justifying the decision on both animal and cash-flow grounds.
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Recommendation: cut about half the cereal for hay and graze the rest, and buy a limited amount of hay only if the feed budget still shows a gap after that.
Animal grounds: late-pregnant ewes need both energy and protein, and a cereal hay or silage is better roughage than dry stubble. Grazing the cereal directly gives high-quality feed but risks the sheep eating it out too fast and leaving bare ground; strip-grazing with a back fence controls this. Cutting half for hay gives a stored reserve that can be fed after lambing when demand peaks.
Cash-flow grounds: hay at $220/t is expensive, and cash is tight until wool is sold. Every tonne bought is cash out the door before income arrives. Home-grown hay from the 40 ha avoids that cash cost, and grain already in storage is a sunk cost that should be used first. The grower should buy hay only to cover a measured shortfall, not as a precaution, and should negotiate delivery timing to match cash flow.
Judgement: use the home-grown feed first, protect ewe condition, and defer purchased hay until the mid-season feed budget confirms the gap. Selling some ewes is the fallback if the gap cannot be closed.
3. The grower asks whether to sell 100 ewes now to reduce demand. Evaluate this option and state the conditions under which it would be the better choice.
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Selling 100 ewes cuts demand by about 11%, from 1.8 t/day to about 1.6 t/day, or roughly 11 t over the 56 days. That is a modest saving and does not close a shortfall of the size estimated.
Selling now also has costs: the ewes are joined, so selling them forfeits the lamb crop and the wool income from those animals; cull ewe prices in a drought are usually depressed because everyone is selling; and the flock loses genetic progress and future replacement capacity.
When selling would be the better choice: if the feed gap cannot be closed even after using the cereal, buying hay, and adjusting stocking rate; if condition score is falling below 2.5 and ewes will not lamb successfully; if cash flow cannot fund purchased feed until wool income arrives; or if the season outlook points to an extended drought rather than a short one.
The better first step is to reduce demand without losing the lamb crop: sell the oldest, emptiest or driest ewes selectively rather than 100 at random, and keep the young, condition-score-3 ewes. That preserves the flock's productive core while cutting demand, which is the judgement the exam is testing.