Teagasc has carried out extensive research on the most economic sales route or finishing system for hill lambs. For most, October is the crunch month in deciding whether to sell lambs or retain and finish on farm. Where grass is available, the option of introducing supplementary feeding (300g per head) at grass will help to maintain average performance at 100g/day through October and into mid-November.

This will lead to heavier lambs for sale and, importantly, more suitable lambs to put on to an intensive finishing diet. For example, 25kg Scottish Blackface lambs finished on an intensive concentrate diet took 73 days on a full finishing diet to reach 39kg liveweight at slaughter, while 29kg lambs took 61 days on average to reach 40.4kg liveweight.

Weight before finishing is key

As concentrate is the primary cost in the system, the heavier lambs are at the start of the finishing period the better. Heavier Scottish Blackface lambs weighing 36.9kg (ram lambs) and 36kg (wether lambs) achieved an average daily gain of 255g and 218g/day respectively, compared with 200g for lighter lambs, and reached slaughter weight of 45kg and 47kg after a finishing period of just 36 days.

Average concentrate daily intake of heavier lambs averaged 1.4kg compared with 1.2kg for lighter lambs, with crossbred lambs consuming higher levels, but capable of returning higher performance.

Important factors to consider are building lambs slowly on to an ad-lib diet, operating a robust health programme and ensuring lambs have access to a roughage source and a clean supply of water, along with regular weighing and drafting to market lambs at the correct weight and fat cover. A full analysis can be found here, with the Teagasc website also providing a lamb finishing calculator.

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