Calculating carry-over silage stocks

Learning from this year’s drought to plan a preventative strategy is good risk management, but calculate figures, don’t guess. In a grazing system, it ideally means budgeting to carry over 300–500 kgDM/cow of silage as an insurance policy for times of feed shortage, says Ian Browne of The Farm Consultancy Group. This will feed 10–12 kgDM/cow/day for over a month. Thus, for 300 cow places, it comes to about 1,000 tonnes of silage.

“Work out how much you need to carry over by measuring what you have and what you need – do a feed budget”, he says. “Using the five-year weather average as a guide, it’s important not to plan around the worst year. Be a realist! Don’t plan for that dry year or a peak yield but choose a sensible average. As a rule of thumb, with an average stocking rate of 2.5 cows/ha, you rarely get into too much trouble and can build reasonable insurance, challenge your grassland, and reduce cake.”

He points out that it's sensible to build flexibility into silage clamps and pit management for carry-over stocks: “People have ended up buying poor quality hay this year to bridge a gap, yet there’s no milk in it. It’s important to allocate good silage to milking cows and be able to access it. Don’t have it mixed up with poorer dry cow silage in the back of the clamp.”