It is best to check sward heights on a regular basis to ensure there is adequate feed for them. The table below is a guide to grass heights for cattle at grass. Other factors such as quality of grazing, stocking rates and weather will also need to be taken into account.
|Type Of Stock
|Set Stocked Grazing System
|Rotational System Field Entry Grazing Height
|Rotational System Field Exit Grazing Height
|Suckler cows & calves
|6 - 7 cm
|7 - 8 cm
The critical point is when to exit a field on rotational grazing systems. But as quality declines, and the thatch of dead material increases towards the base of the plant asking cattle to graze lower will compromise performance, if not gut fill. Grazing to lower heights will also prolong recovery, particularly when the plant is under water stress.
As a simple rule of thumb, later on in the season – where feeding concentrates alongside grass – if grass is reasonably plentiful then concentrates can be fed at 0.5kg per 100kg live weight. Where grass supply is moderate or poor, as is likely on dry fields now burning up and into the slow declining quality of autumn grazings, feeding concentrates at 1kg per 100kg live weight is more likely to be required. The composition of the concentrate should be high in energy and moderate for protein, around 13-14% crude protein on a fresh basis is sufficient and no more than 0.5kg per 100kg live weight is fed in a single feed.
Karen Stewart, Karen.Stewart@sac.co.uk
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